The present disclosure generally relates to methods and apparatus for processing a substrate, and more specifically to methods and apparatus for improving photolithography processes.
Integrated circuits have evolved into complex devices that can include millions of components (e.g., transistors, capacitors and resistors) on a single chip. Photolithography is a process that may be used to form components on a chip. Generally the process of photolithography involves a few basic stages. Initially, a photoresist layer is formed on a substrate. A chemically amplified photoresist may include a resist resin and a photoacid generator. The photoacid generator, upon exposure to electromagnetic radiation in the subsequent exposure stage, alters the solubility of the photoresist in the development process. The electromagnetic radiation may have any suitable wavelength, for example, a 193 nm ArF laser, an electron beam, an ion beam, or other suitable source.
In an exposure stage, a photomask or reticle may be used to selectively expose certain regions of the substrate to electromagnetic radiation. Other exposure methods may be maskless exposure methods. Exposure to light may decompose the photo acid generator, which generates acid and results in a latent acid image in the resist resin. After exposure, the substrate may be heated in a post-exposure bake process. During the post-exposure bake process, the acid generated by the photoacid generator reacts with the resist resin, changing the solubility of the resist during the subsequent development process.
After the post-exposure bake, the substrate, particularly the photoresist layer, is developed and rinsed. Depending on the type of photoresist used, regions of the substrate that were exposed to electromagnetic radiation are either resistant to removal or more prone to removal. After development and rinsing, the pattern of the mask is transferred to the substrate using a wet or dry etch process.
The evolution of chip design continually requires faster circuitry and greater circuit density. The demands for greater circuit density necessitate a reduction in the dimensions of the integrated circuit components. As the dimensions of the integrated circuit components are reduced, more elements are required to be placed in a given area on a semiconductor integrated circuit. Accordingly, the lithography process must transfer even smaller features onto a substrate, and lithography must do so precisely, accurately, and without damage. In order to precisely and accurately transfer features onto a substrate, high resolution lithography may use a light source that provides radiation at small wavelengths. Small wavelengths help to reduce the minimum printable size on a substrate or wafer. However, small wavelength lithography suffers from problems, such as low throughput, increased line edge roughness, and/or decreased resist sensitivity.
An electrode assembly may be utilized to generate an electric field to a photoresist layer disposed on the substrate prior to or after an exposure process so as to modify chemical properties of a portion of the photoresist layer where the electromagnetic radiation is transmitted for improving lithography exposure/development resolution. However, the challenges in implementing such systems have not yet been adequately overcome.
Therefore, there is a need for improved methods and apparatus for improving immersion field guided post exposure bake processes.
The present disclosure generally relates to substrate process apparatus. Specifically, embodiments of the disclosure relate to a substrate apparatus including a chamber body, a substrate carrier, an electrode, a track, and an actuator. The chamber body defining a process volume and includes a bottom surface, one or more sidewalls, and a fluid port disposed through the bottom surface of the chamber body. The electrode is disposed above the bottom surface comprising a major surface. The track is disposed within the chamber body and is configured to guide the substrate carrier to a processing position. A device side of each of the one or more substrates is parallel to a major surface of the electrode while in the processing position. The actuator is operable to position the substrate carrier in a position parallel to at least a portion of the carrier track.
In another embodiment, a substrate processing apparatus includes a chamber body, and a swing assembly. The chamber body defines a process volume and includes a bottom surface, one or more sidewalls, and a fluid port disposed through the bottom surface of the chamber body. The swing assembly includes a substrate carrier with a substrate support surface, an electrode with a major surface disposed parallel to the substrate support surface, and an actuator coupled to the substrate carrier and the electrode and configured to swing the substrate carrier and the electrode about an axis.
In yet another embodiment, a substrate processing method is described. The substrate processing method includes positioning one or more substrates on a substrate carrier while the substrate carrier is in a transfer position. The one or more substrates on the substrate carrier have a substantially horizontal orientation when the substrate carrier is in the transfer position. The method further includes flowing a processing fluid from a fluid port into a process volume of a chamber body and orienting the substrate carrier in a fluid entry position. While in the fluid entry position, the one or more substrates are disposed on the substrate carrier having a fluid entry orientation that is about 60 degrees to about 90 degrees from the substantially horizontal orientation. The method further includes submerging at least a portion of the one or more substrates disposed on the substrate carrier into the processing fluid while in the fluid entry orientation and positioning the substrate carrier at a processing position, wherein the one or more substrates disposed on the substrate carrier are fully submerged within the processing fluid and a device side of the substrate is parallel to a major surface of a second electrode.
In yet another embodiment, a substrate process apparatus includes a base assembly defining a process volume and an electrode assembly. The base assembly includes a bottom surface, one or more sidewalls, a fluid inlet disposed through the chamber body, and a fluid outlet disposed through the chamber body. The electrode assembly includes a perforated electrode and an actuator coupled to a side of the perforated electrode and the base assembly.
So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, may admit to other equally effective embodiments.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.
The present disclosure generally relates to methods and apparatus for post exposure bake processes. Methods and apparatus disclosed herein assist in reducing line edge/width roughness and improving exposure resolution in a photolithography process for semiconductor application.
The methods and apparatus disclosed herein improve the photoresist sensitivity and productivity of photolithography processes. The random diffusion of charged species generated by a photoacid generator during a post exposure bake procedure contributes to line edge/width roughness and reduced resist sensitivity. An electrode assembly, such as those described herein, is utilized to apply an electric field and/or a magnetic field to the photoresist layer during photolithography processes. The field application controls the diffusion of the charged species generated by the photoacid generator. Furthermore, an intermediate medium is utilized between the photoresist layer and the electrode assembly so as to enhance the electric field generated therebetween.
An air gap defined between the photoresist layer and the electrode assembly results in voltage drop applied to the electrode assembly, thus, adversely lowering the level of the electric field desired to be generated to the photoresist layer. Inaccurate levels of the electric field at the photoresist layer may result in insufficient or inaccurate voltage power to drive or create charged species in the photoresist layer in certain desired directions, thus leading to diminished line edge profile control to the photoresist layer. Thus, an intermediate medium is placed between the photoresist layer and the electrode assembly to prevent an air gap from being created therebetween so as to maintain the level of the electric field interacting with the photoresist layer at a certain desired level. By doing so, the charged species generated by the electric field are guided in a desired direction along the line and spacing direction, substantially preventing the line edge/width roughness that results from inaccurate and random diffusion. Thus, a controlled or desired level of electric field as generated increases the accuracy and sensitivity of the photoresist layer to expose and/or development processes. In one example, the intermediate medium is a non-gas phase medium, such as a slurry, gel, liquid solution, or a solid state medium that may efficiently maintain voltage levels as applied at a determined range when transmitting from the electrode assembly to the photoresist layer disposed on the substrate.
Even while using the intermediate medium, a voltage drop is still present between the photoresist layer and the electrode assembly. This voltage drop is directly related to the distance between the photoresist layer and the electrode assembly. Therefore, reducing the distance between the photoresist layer and the electrode assembly assists in improving the uniformity of the electric field between the photoresist layer and the electrode assembly. Another consideration while using the intermediate medium is bubbling between the photoresist layer and the electrode assembly. Bubbling and the formation of air pockets between the photoresist layer and the electrode assembly causes non-uniformities within the electric field and therefore increases the number of defects and inaccuracies within the photoresist after the post-exposure bake process. The present apparatus and methods described herein for reducing the distance between the photoresist and the electrode assembly beneficially reduces the number of bubbles or air pockets between the photoresist layer and the electrode assembly.
The chamber body 102 includes a bottom surface 124, one or more sidewalls 104, a first fluid port 120 disposed through the bottom surface 124 of the chamber body 102, a second fluid port 125 disposed through the bottom surface 124 of the chamber body 102, a track 106, and a loading device 114.
The bottom surface 124 and the one or more sidewalls 104 define a process volume 105. The process volume 105 is at least partially filled with the intermediate medium 139 through one or both of the first fluid port 120 and the second fluid port 125 as described herein. The process volume 105 may be at least partially open on one side as the intermediate medium 139 is a liquid, slurry, gel, or solid state medium. The intermediate medium 139 flows from one or both of the first fluid port 120 and the second fluid port 125 to cover the bottom surface 124 of the chamber body 102, before filling the process volume 105 and covering the one or more sidewalls 104. The intermediate medium 139 completely fills the process volume 105, such that the intermediate medium 139 rises to the level of the top surface 140 of the one or more sidewalls 104 and spills over the one or more sidewalls 104 into a fluid accumulation basin 112. The bottom surface 124 and the one or more sidewalls 104 of the chamber body 102 are heated. In some embodiments, the chamber body 102 includes one or more resistive heating elements or heating channels disposed therein (not shown).
The fluid accumulation basin 112 is disposed outside of the chamber body 102, such that the fluid accumulation basin 112 at least partially surrounds the chamber body 102. The fluid accumulation basin 112 is disposed below the bottom surface 124 of the chamber body 102. Alternatively, the fluid accumulation basin 112 may be attached to one or more of the sidewalls 104. The fluid accumulation basin 112 acts as a receptacle or catch basin for the intermediate medium 139 which spills over the sidewalls 104 from the process volume 105. The fluid accumulation basin 112 includes a drain (not shown) to remove the intermediate medium 139 from the fluid accumulation basin 112.
The first fluid port 120 and the second fluid port 125 are disposed through the bottom surface 124 of the chamber body 102. Each of the first fluid port 120 and the second fluid port 125 comprise either a fluid inlet or a fluid outlet. In some embodiments, the first fluid port 120 is a fluid inlet, while the second fluid port 125 is a fluid outlet. In this embodiment, the intermediate medium 139 may be continuously circulated through the process volume 105 as fluid is introduced into the process volume 105 through the first fluid port 120 and fluid is either simultaneously or periodically removed through the second fluid port 120.
In yet other embodiments, only the first fluid port 120 is present and the intermediate medium 139 is removed from the chamber body 102 using an overflow valve 129 between process operations. The overflow valve 129 may be configured to be opened or closed between process operations. In some embodiments, when the overflow valve 129 is in an open position, the intermediate medium 139 drains into the fluid accumulation basin 112. The overflow valve 129 may alternatively be coupled to a conduit (not shown) for removal of the intermediate medium 139. The overflow valve 129 is disposed on the bottom surface 124 of the chamber body 102.
The first fluid port 120 includes a first fluid conduit 121, a first port valve 122, and a first fluid source 123. The first fluid conduit 121 is fluidly connected to the chamber body 102 and the process volume 105. The first fluid conduit 121 is disposed between the bottom surface 124 of the chamber body 102 and the first fluid source 123. The first fluid conduit 121 is a pipe or channel. The first fluid conduit 121 has a first end connected to the process volume 105 on the bottom surface 124 of the chamber body 102 and a second end connected to the first fluid source 123. The first fluid source 123 is a fluid source configured to provide the intermediate medium 139 into the process volume 105. The first fluid source 123 may be a part of a fluid panel for distribution of the intermediate medium 139. The first fluid source 123 may additionally be configured to provide other fluids to the process volume 105, such as cleaning fluids. The first fluid source 123 controls the flow of the intermediate medium 139 into the process volume 105. The first port valve 122 is disposed along the first fluid conduit 121 and between the first fluid source 123 and the process volume 105. The first port valve 122 is a gate valve or throttle valve. The first port valve 122 is configured to control the flow of the intermediate medium 139 into the process volume 105, such that in some embodiments, the first port valve 122 fine tunes the flow of the intermediate medium 139 to the process volume 105. In some embodiments, the first port valve 122 is configured to be in an open or a closed position and can stop fluid from flowing into the process volume 105 from the first fluid source 123. The first fluid source 123 may preheat the process fluid in some embodiments. In some embodiments, the process fluid is preheated to a temperature of about 100° C. to about 200° C., such as about 110° C. to about 150° C., such as about 115° C. to about 130° C.
The second fluid port 125 includes a second fluid conduit 126, a second port valve 127, and a second fluid source 128. The second fluid port 125 may be configured as either an additional fluid inlet or a fluid outlet. When utilized as a fluid inlet, the second fluid conduit 126 is similar to the first fluid conduit 121, the second port valve 127 is similar to the first port valve 122, and the second fluid source 128 is similar to the first fluid source 123. When the second fluid port is configured as a fluid outlet, the second fluid conduit 126 and the second port valve 127 remain the same, but the second fluid source 128 is replaced with a fluid pump. The fluid pump serves to remove fluid from the process volume 105 through the second fluid conduit 126. The first fluid port 120 and the second fluid port 125 are disposed on opposite sides of the bottom wall 124 in order to increase the circulation of the intermediate medium 139 within the process volume 105.
The track 106 is disposed at least partially within the process volume 105. The track 106 includes a first track segment 107, a transition track segment 108, and a second track segment 109. The first track segment 107 is disposed at an angle to a horizontal plane. The horizontal plane may be parallel to the x-axis, the bottom surface 124 of the chamber body 102, or parallel to the second track segment 109. The first track segment 107 is connected to the transition track segment 108 and extends upwards towards the top of the chamber body 102, such that the first track segment 107 extends from the transition track segment 108 towards the top surface 140 of the one or more sidewalls 104. In some embodiments, the first track segment 107 extends along one of the one or more sidewalls 104 and a top portion of the first track segment 107 is level with the top surface of the intermediate medium 139 when the process volume 105 is full. The first track segment 107 is a linear track segment. However, in some embodiment, the first track segment 107 may be curved. The first track segment 107 is angled such that the angle of entry of a substrate and a substrate carrier is a non-zero angle. The angle of entry is the initial angle at which the major plane of the substrate 150 and the substrate carrier 101 intersects the horizontal plane as the substrate 150 and/or the substrate carrier 101 enter the process volume 105 and the intermediate medium 139. The major plane or major surface of the substrate 150 and the substrate carrier 101 is defined as the plane passing through the top surface. With respect to the substrate 150, the major plane or major surface is a plane parallel with the top surface or device side of the substrate 150. With respect to the substrate carrier 101, the major plane or major surface is a plane parallel to the top surface of the substrate carrier 101, where the top surface is parallel to the device side of the substrate 150 when the substrate is disposed therein. The first track segment 107 has an angle of entry of about 70 degrees to about 90 degrees from the horizontal plane. The transition track segment 108 is a curved section of track which connects the first track segment 107 and the second track segment 109. The second track segment 109 is a horizontal track segment. The second track segment 109 is parallel to the horizontal plane and the x-axis. The second track segment 109 is a linear track segment and is disposed on top of connectors 110, which couple the second track segment 109 of the track 106 to the bottom surface 124 of the chamber body 102. The connectors 110 are additionally be grounded, which grounds the track 106. The track 106 is connected to ground by an electrical connection 130. There is an end stop 111 connected to the end of the second track segment 109 opposite the connection to the transition track segment 108. The end stop 111 serves as a guide to ensure the carrier 101 is properly positioned on the second track segment 109 during substrate processing.
The loading device 114 is disposed on top of the top surface 140 of the one or more sidewalls 104. The loading device 114 is configured to couple to the carrier 101 at a top surface 141 of the loading device 114 using one or more connectors. The one or more connectors include a front connector 118a and a back connector 118b. Each of the front connector 118a and the back connector 118b may be actuators for moving the carrier 101 along the loading device 114 and the track 106. In some embodiments, the front connector 118a and the back connector 118b are coupled to the loading device 114 and may transition to being coupled to the track 106 as the carrier 101 moves to a processing position. The front connector 118a and the back connector 118b may be shuttle connections or sliders, such that each of the front connector 118a and the back connector 118b interlock with the loading device 114 and the track 106 during transfer. In some embodiments, the carrier 101 is transferred along the track 106 and the loading device 114 using the front connector 118a and/or the back connector 118b as an actuator. In yet other embodiments, the carrier 101 is acted upon by an outside actuation device or is on a conveyor disposed within the track 106 and the loading device.
The loading device 114 is coupled to the chamber body 102 using an actuator 116. The actuator 116 is coupled to a distal end of the loading device 114 closest to the track 106 and to the top surface 140 of the one or more sidewalls 104. The actuator 116 is configured to swing the loading device 114 along with the carrier 101 from a horizontal position to an angled position. As shown in
The electrode assembly 135 is disposed above the chamber body 102. The electrode assembly 135 includes an electrostatic mesh 136, a linear actuator 137, and a power source 138. The electrostatic mesh 136 is a conductive mesh which forms an electrode. The electrostatic mesh 136 has a linear bottom surface, which may be defined as a major surface of the electrostatic mesh 136. The major surface of the electrostatic mesh 136 is the surface configured to be parallel to the device side of the substrate 150 when in a processing position. The electrostatic mesh 136 may be woven in one or more layers and includes a plurality of openings disposed therethrough. In some embodiments, the electrostatic mesh 136 is a finely perforated electrode plate. The electrostatic mesh 136 is utilized in order to reduce the amount of bubbles or gas pockets which are trapped under the electrode assembly 135 as the electrode assembly 135 is submerged into the intermediate medium 139. The electrostatic mesh 136 in some embodiments, is a non-metal mesh, such as a silicon carbide mesh. In other embodiments, the electrostatic mesh 136 is a conductive metal mesh, such as a copper, aluminum, or a steel mesh. The linear actuator 137 is coupled to the top surface of the electrostatic mesh 136 in order to enable the vertical movement of the electrostatic mesh 136. The linear actuator 137 may be coupled to the top surface of a process environment (not shown) and extends vertically downward. The power source 138 is electrically coupled to the electrostatic mesh 136 through the linear actuator 137. The power source 138 is configured to apply power to the electrostatic mesh 136. In some embodiments, an electrical potential of up to 5000 V is applied to the electrostatic mesh 136 by the power source 138, such as less than 4000 V, such as less than 3000 V. As shown in
During the first operation 802, a process fluid, such as the intermediate medium 139, is introduced into the process volume 105. The process fluid is introduced through one or a combination of the first fluid port 120 or the second fluid port 125. The process fluid may be continuously circulated within the process volume 105 and flown over the top surface 140 of the one or more sidewalls 104. In some embodiments, the entire process volume 105 may be emptied of the process fluid between each substrate processed. In yet other embodiments, since the process fluid is continuously circulated, the process volume may remain full between each substrate processed.
During the second operation 804, a substrate, such as the substrate 150 of
After the substrate 150 has been secured by the carrier 101 in the transfer position of
While in the angled position, the loading device 114 is in line with an upper portion of the first track segment 107 of the track 106. The top surface 141 of the loading device 114 is in line with the top surface 142 of the first track segment 107. The alignment of the top surface 141 of the loading device 114 and the top surface 142 of the first track segment 107 enables the carrier 101 to be transferred onto the first track segment 107 from the loading device 114. In some embodiments, the loading device 114 and the first track segment 107 interact while in the angled position and couple together.
After the loading device 114 is swung into the angled position, the carrier 101 and the substrate 150 are transferred from the loading device 114 onto the first track segment 107 and into the process volume 105 during a fifth operation 810. The transfer of the carrier 101 and the substrate 150 from the loading device 114 onto the first track segment 107 is shown in
The carrier 101 reaches the transition track segment 108 before the carrier 101 is fully submerged by the intermediate medium 139. As the carrier 101 reaches the transition track segment 108, the carrier 101 is swung from the angle of the angled position to an angle closer to a horizontal. The swinging motion of the carrier 101 and the substrate 150 as the carrier 101 and the substrate 150 are submerged has been found to further reduce the number and size of bubbles accumulated around the carrier 101 and the substrate 150. The swinging motion additionally is beneficial in that it enables the use of a shallower chamber body 102. The use of a shallow chamber body 102 additionally reduces the size of the overall immersion field guided post-exposure bake chamber 100. The use of separate front connectors 118a and back connectors 118b additionally enables the swinging motion by allowing the carrier 101 to travel along a curved track.
After the carrier 101 and the substrate 150 are fully submerged within the intermediate medium 139, the carrier 101 and the substrate 150 are transferred to a process position within the process volume 105 during a sixth operation 812. The process position of the carrier 101 and the substrate 150 is shown in
After the carrier 101 and the substrate 150 have been placed in the process position, the electrostatic mesh 136 is lowered into the process volume 105 at a position parallel to the top device side surface of the substrate 150. In some embodiments, the electrostatic mesh 136 may be lowered throughout the first through sixth operations 802-812, but the electrostatic mesh 136 is only brought to a processing position after the carrier 101 has reached the process position. The electrostatic mesh 136 is placed at a position in close contact with and parallel to the device side of the substrate 150, such that the bottom surface of the electrostatic mesh 136 is a second height H2 from the device side of the substrate 150. The second height H2 is less than about 7 mm, such as less than about 5 mm, such as less than about 3 mm, such as less than about 1 mm, such as less than about 0.5 mm. In the embodiment described herein, it is possible to reduce the second height H2 as there are limited mechanical barriers between the device side of the substrate 150 and the electrostatic mesh 136.
Once the seventh operation 814 is complete and the electrostatic mesh 136 is in a process position, an electric field is applied to the substrate 150 and a post exposure bake process is performed during an eighth operation 816. The electric field is distributed between the carrier 101, which serves as a first electrode, and the electrostatic mesh 136, which serves as a second electrode. The electric field may be created by applying a voltage differential of up to about 5000 V, such as up to about 3500 V, such as up to about 3000 V. The electric field between the electrostatic mesh 136 and the substrate 150 is less than about 10×106 V/m, such as less than 1×106 V/m, such as less than 1×105 V/m. The electric field is applied to the substrate 150 until the post exposure bake operation is complete.
After the application of the electric field during the eighth operation 816, the electrostatic mesh 136 is moved away from the process position and transferred out of the process volume 105 during a ninth operation 818. As the electrostatic mesh 136 is removed from the process volume 105, the carrier 101 is also removed from the process volume 105 along a similar path as that which it followed into the process volume 105. During the ninth operation 818, the carrier 101 may be transferred back to the transfer position, such that the substrate 150 may be removed from the carrier by a robot (not shown).
After the carrier and the electrostatic mesh 136 are removed from the process volume 105 during the ninth operation 818, the process volume 105 is optionally drained of process fluid, such as the intermediate medium 139. The process fluid is drained from the process volume 105 during the tenth operation 820.
The second substrate carrier 201 includes a lower carrier portion 202 and an electrode lid 203. The electrode lid 203 is coupled to the lower carrier portion 202 at one end, such that the electrode lid 203 swings between a substrate receiving position, such as shown in
The electrode lid 203 swings to a closed position after the substrate 150 is loaded into the carrier portion 202. Closing the carrier portion 202 may assist in securing the substrate 150 to the carrier portion 202 as the second substrate carrier 201 and the substrate 150 are rotated and transferred along the track 106. The electrode lid 203 is electrically coupled to the power source 238 through the track 106. The power source 238 is configured to apply power to the electrode lid 203. In some embodiments, an electrical potential of up to 5000 V is applied to the electrode lid 203 by the power source 238, such as less than 4000 V, such as less than 3000 V. In some embodiments, the carrier portion 202 is electrically grounded 130, such that one of the two rails of the track 106 included a lead line to electrically ground the track 106 while the other of the two rails of the track 106 includes a lead line to couple the power source 238 to the electrode lid 203. The electrode lid 203 may be electrically coupled to the track 106 through one or more of the connectors 118a, 118b.
A method 900 can be described with reference to
The second substrate carrier 201 is similarly utilized to secure the substrate 150 during a third operation 906. During the third operation 906, the electrode lid 203 is swung to a closed position and the substrate 150 is secured within the second substrate carrier 201. The substrate 150 is either secured before or during the lowering of the electrode lid 203 to the closed position. Subsequent to the third operation 906, the substrate 150 is transferred into the process volume 105 from the loading device 114 during a fourth operation 908 and a fifth operation 910. The fourth operation 908 and the fifth operation 910 are similar to the fourth operation 808 and the fifth operation 810 of the method 800 of
As shown in
After the second substrate carrier 201 is positioned in the process position, an electric field is applied to the substrate 150. The electric field is applied by providing power to the electrode lid 203 as the substrate 150 is grounded by the carrier portion 202 of the second substrate carrier 201. The application of the electric field to the substrate 150 is similar to the application of the electric field described with respect to the eighth operation 816 of the method 800 of
An opening 310 is disposed between the first portion 302 and the second portion 304 and opposite the span portion 306. The opening 310 is disposed to allow for a robot (not shown) to place and remove the substrate 150 from the carrier 101, such that a blade of the robot is temporarily inserted between the first portion 302 and the second portion 304. Once the substrate 150 has been placed on the carrier 101 by the robot, one or more mechanical clamps 308a, 308b, 308c are actuated to a clamping position to secure the substrate 150. The one or more mechanical clamps includes a first clamp 308a, a second clamp 308b, and a third clamp 308c. The first clamp 308a is attached to the span portion 306, the second clamp 308b is attached to the second portion 304, and the third clamp 308c is attached to the first portion 302. Each of the first clamp 308a, the second clamp 308b, and the third clamp 308c are evenly distributed about the depression 316, such that each of the clamps 308a, 308b, 308c is disposed at an angle of about 180 degrees from one another. Each of the first clamp 308a, the second clamp 308b, and the third clamp 308c are disposed within a corresponding one of a plurality of divots 307. Each divot 307 is a small recess formed within the top surface of the carrier 101. The divots 307 are disposed below each of the first clamp 308a, the second clamp 308b, and the third clamp 308c. Each of the divots 307 are disposed slightly further outward from the first clamp 308a, the second clamp 308b, and the third clamp 308c so that the first clamp 308a, the second clamp 308b, and the third clamp 308c may retract from a clamping position into the divots 307 and release the substrate 150. In some embodiments, there may be more or less clamps to secure the substrate 150 inside of the depression 316. In some embodiments there may be only a single clamp, two clamps, or four or more clamps. The number of clamps utilized may depend upon the size of the substrate 150 and the type of clamping mechanism.
The substrate 150 is disposed within the depression 316. The depression. As shown in
The lower carrier portion 202 includes the first portion 302, the second portion 304, and the span portion 306. The depression 316 is formed within both the first portion 302 and the second portion 304. The opening 310 is disposed between the first portion 302 and the second portion 304 and opposite the span portion 306. The one or more mechanical clamps 308a, 308b, 308c are additionally still utilized. The lower carrier portion 202 of
The electrode lid 203 includes a perforated electrode 323, the protrusion 324, and an actuator 322 (shown in
The perforated electrode 323 is placed at a position in close contact with and parallel to the device side of the substrate 150, such that the bottom surface 321 of the perforated electrode 323 is a third height H3 from the top surface 151 of the substrate 150. The third height H3 is less than about 7 mm, such as less than about 5 mm, such as less than about 3 mm, such as less than about 1 mm, such as less than about 0.5 mm. The third height H3 may be reduced as there are limited mechanical barriers between the device side of the substrate 150 and the perforated electrode 323.
As shown in
The protrusion 339 surrounds the substrate carrier 201, which improves electric field uniformity near the edges of the substrate 150 during processing. In some embodiments, each of the first portion 302, the second portion 304, the span portion 306, and the protrusion 339 are coated with a similar material on at least a portion of the surfaces of the first portion 302, the second portion 304, the span portion 306, and the protrusion 339 in order to better facilitate formation of a uniform magnetic field between the top surface 151 of the substrate 150 and the perforated electrode 323.
Each of the clamps 308a, 308b, 308c being coupled to the bottom surface 321 of the perforated electrode 323 further reduces the mechanical complexity of clamping the substrate 150 because the substrate 150 is clamped into place within the substrate carrier 201 as the perforated electrode 323 swings to a closed position. Although not explicitly shown in the figures, the clamps 308a, 308b, 308c may alternatively be coupled to the bottom surface 321 of the perforated electrode 323 in the embodiments of
As illustrated in
The one or more linking members 410 are rigid electrical insulators. The one or more linking members 410 may be formed from any one of a ceramic, a polymer, or a combination of ceramic and a polymer. In some embodiments, the one or more linking members 410 are made of quartz or alumina. The one or more linking members 410 are coupled to the edges of the electrode 436 and the swing carrier 401. The one or more linking members 410 are rigid to maintain a constant displacement between the electrode 436 and the swing carrier 401.
In some embodiments, the one or more linking members 410 may be coupled with one or more linear actuators 412, which enable the displacement between the electrode 436 and the swing carrier 401 to be increased or decreased. The one or more linear actuators 412 are connected to the electrode 436 and the one or more linking members 410 and move the one or more linking members 410 with respect to the electrode 436. The one or more linking members 410 is fixed to the swing carrier 401 and enable the movement of the swing carrier 401 closer to and further away from the electrode 436 as the one or more linear actuators 412 actuate the one or more linking members 410.
It is envisioned the one or more linear actuators 412 would space apart the electrode 436 and the swing carrier 401 during loading of the substrate 150 into the swing carrier 401. The space between the electrode 436 and the swing carrier 401 would then be reduced by the one or more linear actuators 412 after the substrate 150 has been loaded onto the swing carrier 401 and the swing carrier 401 is prepared for processing. Reducing the displacement between the electrode 436 and the swing carrier 401 assists in maintaining a uniform electric field between the electrode 436 and the substrate 150 during post exposure bake processes.
The substrate 150 is secured to the swing carrier 401 using one or more clamps 408. The one or more clamps 408 are similar to the clamps 308a, 308b, 308c described with respect to
The actuator coupling 437 couples to electrode 436 to an actuator 420. The actuator 420 is configured to rotate the entire swing assembly about a swing axis B. The swing axis B is offset from both the electrode 436 and the swing carrier 401.
The first operation 1002, the second operation 1004, and the third operation 1006 are illustrated with respect to
The second operation 1004 includes positioning the substrate 150 on the swing carrier 401, while the swing carrier 401 is in a transfer position. The transfer position is a position parallel to electrode 436 and the horizontal plane as previously described. The substrate 150 is placed onto the swing carrier 401 using a robot (not shown). The swing carrier 401 and the electrode 436 are in a spaced position while positioning the substrate 150 onto the swing carrier 401.
After the substrate 150 is placed on the swing carrier 401, the substrate 150 is secured to the swing carrier 401 during the third operation 1006. The substrate 150 is secured to the swing carrier 401 using one or more clamps 408. The one or more clamps 408 are either mechanical, pneumatic, or hydraulic clamps. The securing of the substrate 150 to the swing carrier 401 enables to the swing carrier 401 and the electrode 436 to be rotated about the swing axis B without the substrate 150 moving or falling out of the swing carrier 401.
After the substrate 150 is secured to the swing carrier 401, the electrode 436, the swing carrier 401, and the substrate 150 are swung to an angled position from the horizontal transfer position during a fourth operation 1008. The swing carrier 401, the electrode 436, and the substrate 150 are swung about the swing axis B to an angled position as illustrated in
During the fifth operation 1010, the electrode 436, the swing carrier 401, and the substrate 150 are transferred into the process volume and submerged in the intermediate medium 139. The fifth operation 1010 is illustrated in
After the entire electrode 436, the swing carrier 401, and the substrate 150 have been submerged in the intermediate medium 139, the swing assembly 450 is transferred to a process position within the process volume in a sixth operation 1012. The process position of the swing assembly 450 is illustrated in
While in the process position, a seventh operation 1014 of applying an electric field to the substrate 150 and performing a post exposure bake process is performed. The seventh operation 1014 is similar to the eighth operation 816 of the method 800 of
After the post exposure bake process of the seventh operation 1014 is performed, the electrode 436, the swing carrier 401, and the substrate 150 are transferred out of the process volume 105 during an eighth operation 1016. During the eighth operation 1016, the intermediate medium 139 in a method similar to, but reversed from, the method utilized to place the electrode 436, the swing carrier 401, and the substrate 150 within the process volume 105.
During a ninth operation 1018, the process fluid, such as the intermediate medium 139, is drained from the process volume 105 through one of the first fluid source 120, the second fluid source 125, or the overflow valve 129. The draining of the process fluid from the process volume 105 of the ninth operation 1018 is similar to the tenth operation 820 of the method 800 of
The batch electrode device 536 includes a plurality of single electrodes 506a-506f. The batch electrode device 536 is disposed within the process volume 105 of the chamber body 102 and is configured to be completely submerged in process fluid, such as the intermediate medium 139, while the process volume 105 is sufficiently full of intermediate medium 139. The plurality of single electrodes 506a-506f are disposed parallel with one another and perpendicular to the bottom surface 124 of the chamber body 102. Each of the single electrodes 506a-506f include a major surface, which is configured to be a planar surface parallel to the substrate 150 while the substrate 150 is in a process position. The major surface may be the largest planar surface of the single electrodes 506a-506f and configured to form an electric field. The plurality of electrodes 506a-506f are disposed along one or more support beams 507. The one or more support beams 507 are disposed perpendicular to the electrodes 506a-506f. The one or more support beams 507 are coupled to a sidewall 104 of the chamber body 102 at a coupling 508. The plurality of electrodes 506a-506f are spaced along the one or more support beams 507 and centered about batch electrode axis D. The batch electrode axis D is perpendicular to the chamber body 102 sidewall 104.
The coupling 508 may be disposed on a track (not shown) separate, but parallel to, the sidewall track 510. Alternatively, each of the electrodes 506a-506f may be individually mounted onto a sidewall 104 of the process chamber without the use of the support beam. Mounting each electrode of the plurality of electrodes 506a-506f allows for each electrode to be replaced separately and reduces the mechanical complexity within the process volume 105. The batch electrode device 536 is electrically coupled to a power source 138, such that each of the electrodes 506a-506f are electrically coupled to the power source 138. In some embodiments, the power source 138 includes multiple power sources.
The batch carrier 501 is disposed along the sidewall track 510 and includes a plurality of single substrate carriers or single carriers 502a-502f. The plurality of single carriers 502a-502f are coupled together by one or more support beams 504. The plurality of single carriers 502a-502f are parallel to one another and spaced apart along the one or more support beams 504. The plurality of single carriers 502a-502f are centered about a batch carrier axis C. The batch carrier axis C is parallel to the direction in which the one or more support beams 504 run. The batch carrier 501 is coupled to the chamber body by an actuator 505. The actuator 505 is coupled to the sidewall track 510. The actuator 505 is configured to attach the batch carrier 501 to the sidewall track 510 and rotate the batch carrier 501 about the rotation axis E. The plurality of single carriers 502a-502f are grounded. In some embodiments, the batch carrier 501 is a cassette having slots for retaining individual substrates.
The sidewall track 510 is a vertical track attached to and disposed along a sidewall of the one or more sidewalls 104. The sidewall track 510 is a linear track and may be coupled to the one or more sidewalls 104 using fasteners. The sidewall track 510 may extend above the level at which the chamber body 102 is filled with the intermediate medium 139. In some embodiments, the sidewall track 510 extends out of the chamber volume 105 and above the top surface 140 of the one or more sidewalls 104. The sidewall track 510 extends out of the chamber volume 105 to allow for complete rotation of the batch carrier 501 to a horizontal position without the batch carrier 501 impacting the batch electrode device 536.
The second operation 1104 includes positioning a plurality of substrates 150 onto the batch carrier 501. The plurality of substrates 150 are placed on the batch carrier 501 by one or more robots (not shown), while the batch carrier 501 is in a horizontal transfer position. The horizontal transfer position is a position in which the surface of each of the substrates 150 positioned on the single carriers 502a-502f is parallel to the horizontal plane and perpendicular to the main surface of each of the electrodes 506a-506f.
After the substrates 150 are placed on each of the single carriers 502a-502f of the batch carrier 501, the substrates 150 are secured to each of the single carriers 502a-502f during a third operation 1106. Each of the substrates 150 may be secured to the single carriers 502a-502f using one or more clamps 528a-528c (
After the substrates 150 are secured to the batch carrier 501, the batch carrier 501 and the substrates 150 are swung about the rotation axis E during a fourth operation 1108. The swinging of the batch carrier 501 about the rotation axis E, swings the batch carrier 501 and the substrates 150 by an angle 84 to a vertical intermediate position.
After the fourth operation 1108, the single carriers 502a-502f and the substrates 150 are partially submerged within the intermediate medium 139 or not submerged at all depending upon the depth of the intermediate medium 139 and the location of the electrodes 506a-506f.
After the fourth operation 1108, the batch carrier 501 and the substrates 150 are transferred into the process volume 105 along the sidewall track 510 during a fifth operation 1110. The batch carrier 501 and the substrates 150 are transferred to a processing position as shown in
The top surface of one of the substrates 150 is separated from the bottom surface of one of the electrodes 506a-506f by a distance D1. The distance D1 is less than about 7 mm, such as less than about 5 mm, such as less than about 3 mm, such as less than about 1 mm, such as less than about 0.5 mm. In the embodiment described herein, it is possible to reduce the distance D1 as there are limited mechanical barriers between the device side of the substrate 150 and the electrodes 506a-506f.
After the fifth operation 1110, an electric field is applied to each of the substrates 150 within the batch carrier 501 during a sixth operation 1112. The sixth operation 1112 is similar to the eighth operation 816 of the method 800 of
During a eighth operation 1116, the process fluid, such as the intermediate medium 139, is drained from the process volume 105 through one of the first fluid source 120, the second fluid source 125, or the overflow valve 129. The draining of the process fluid from the process volume 105 during the eighth operation 1116 is similar to the tenth operation 820 of the method 800 of
Each of the single carriers 502a-502f include a holding portion 520 and an insulated portion 522. The holding portion 520 is configured to hold the substrate 150. The insulated portion 522 is formed from an insulating material for electrically insulating the substrate 150 from the magnetic field of any electrodes, such as the electrodes 506a-506f disposed below the insulated portion 522. The holding portion 520 is disposed above the insulated portion 522, such that each substrate 150 has an insulated portion 522 disposed therebetween while disposed on the batch carrier 501.
An opening 610 is disposed between the first portion 602 and the second portion 604 and opposite the span portion 606. The opening 610 is disposed to allow for a robot (not shown) to place and remove the substrate 150 from the single carrier 502a-502f, such that a blade of the robot is temporarily inserted between the first portion 602 and the second portion 604. Once the substrate 150 has been placed on the single carrier 502a-502f by the robot, one or more mechanical clamps 528a, 528b, 528c are actuated to a clamping position to secure the substrate 150. The one or more mechanical clamps includes a first clamp 528a, a second clamp 528b, and a third clamp 528c. The first clamp 528a is attached to the span portion 606, the second clamp 528b is attached to the second portion 604, and the third clamp 528c is attached to the first portion 602. Each of the first clamp 528a, the second clamp 528b, and the third clamp 528c are evenly distributed about the depression, such that each of the clamps 528a, 528b, 528c is disposed at an angle of about 180 degrees from one another. In some embodiments, there may be more or less clamps to secure the substrate 150. In some embodiments a hydraulic or a pneumatic clamp may be used.
The support beams 507a, 507b are disposed through the single carrier 502a-502f. The first support beam 507a is connected to the first portion 602 and the second support beam 507b is connected to the second portion 604. Each of the support beams 507a, 507b are disposed around an outer edge of the single carrier 502a-502f and are configured to allow the substrate 150 to be placed onto the single carrier 502a-502f through the opening 610. Underneath the single carrier 502a-502f is the insulated portion 522. The insulated portion 522 is disposed underneath the whole of the single carrier 502a-502f and the substrate 150.
The base portion 701 of the immersion field guided post exposure bake chamber 700 includes a body 707 and a weir 708. The body 707 forms the bottom surface 726 and the sidewalls 724 of the base portion 701. The sidewalls 724 extend upwards from the bottom surface 726 and towards the electrode assembly 703. The bottom surface 726 is configured to support the substrate 150 and includes a cavity 722 disposed below the substrate 150. The cavity 722 is configured to allow a robot blade (not shown) to be disposed therein, such that the substrate 150 may be placed on the bottom surface 726 by a robot blade and the robot blade could then be removed from beneath the substrate 150 without contacting any of the components of the base portion 701. The sidewalls 724 surround at least a portion of the substrate 150.
The base portion 701 further includes one or more fluid inlets 702 and one or more fluid outlets 704. The one or more fluid inlets 702 may be a plurality of fluid inlets 702 surrounding the substrate 150 and disposed along the inner surface of the sidewalls 724. The one or more fluid outlets 704 are a plurality of outlets 704 surrounding the substrate 150 and disposed through the bottom surface 726 of the body 707. The one or more fluid inlets 702 are in fluid communication with a fluid source 710. The fluid source 710 is similar to the first fluid source 123. The fluid source 710 supplies processing fluid to the process volume 705. The one or more fluid outlets 704 are in fluid communication with an evacuation pump 712. The evacuation pump 712 is configured to remove the process fluid from the process volume 705 after the substrate 150 has been processed using an electric field. The one or more fluid outlets 704 are disposed through the bottom surface 726 of the base portion 701 to allow all fluid to be removed from the process volume 705 regardless of the fill level. In some embodiments, the one or more fluid inlets 702 may also be formed through the bottom surface 726. Each of the fluid inlets 702 and the fluid outlets 704 are parts of an annular channel disposed within the base portion 701. Each of the fluid source 710 and the evacuation pump 712 are in fluid contact with annular channels disposed through the base portion 701, wherein the annular channels are in fluid communication with the process volume 705 through the fluid inlets 702 and the fluid outlets 704 respectively.
The substrate 150 is clamped to the bottom surface 726 of the base portion 701 by one or more mechanical clamps 308a, 308b, 308c. The one or more mechanical clamps 308a, 308b, 308c are described in greater detail with respect to
The electrode assembly 703 is disposed on top of the base portion 701 and forms a lid. The electrode assembly 703 includes a perforated electrode 323. The perforated electrode 323 is described in greater detail with respect to
The weir 708 is disposed outside of the process volume 705. The weir 708 is coupled to the base portion 701 and collects excess fluid which escapes through the perforated electrode 323. The weir 708 includes a basin 720 disposed between the weir 708 and the base portion 701. In some embodiments, process fluid from the process volume 705 spills out of the process volume 705 through the perforated electrode 323. The use of excess process fluid may be beneficial and utilized to reduce the amount of bubbles within the process volume 705 during application of the electric field 914. An outlet 706 is formed through the weir 708 and fluidly couples a second evacuation pump 714 to the basin 720 to allow for fluid removal from the basin 720. The weir 708 and the basin 720 may surround the base portion 701.
The apparatus of
The first operation 1202 includes positioning a substrate, such as the substrate 150, within the base portion 701, while the electrode assembly 703 is in an open position. The open position of the first operation 1202 is illustrated in
Subsequent to the first operation 1202, a second operation 1204 is performed to secure the substrate 150 to the base portion 701. Securing the substrate 150 to the base portion 701 may include clamping the substrate 150 with the one or more mechanical clamps 308a, 308b, 308c and/or swinging the perforated electrode 323 to a closed position.
In some embodiments, swinging the perforated electrode 323 to a closed position is part of a third operation 1206 subsequent to the securing of the substrate 150, or in some embodiments, the second operation 1204 and the third operation 1206 are performed simultaneously.
Subsequent to the third operation 1206, a fourth operation 1208 of introducing a process fluid into the process volume 705 is performed. The process fluid enters the process volume 705 through the one or more fluid inlets 702 and fills the process volume 705. Some of the process fluid may spill out of the process volume 705 through the perforated electrode 323 and fall into the weir 708. Subsequent to or simultaneously with the introduction of the process fluid, a fifth operation 1210 is performed to heat the base portion 701 and the process volume 705. Heating the base portion 701 and the process volume 705 may be performed with one of the heating assembly 740 of
Subsequent to the heating during the fifth operation 1210, a sixth operation 1212 is performed by applying an electric field to the substrate 150 by the perforated electrode 323. Applying the electric field performs a post exposure bake process on the substrate and the photoresist disposed thereon. After the post exposure bake process of the sixth operation 1212, the process fluid is drained from the process volume 105 through the one or more fluid outlets 704 during a seventh operation 1214 and the substrate 150 is removed by an indexing robot (not shown) during an eighth operation 1216.
Embodiments described herein are beneficial in that substrates may be processed horizontally, while reducing bubbling effects on the post exposure bake process. Embodiments described herein also allow for the electrodes and substrate to be disposed closer together during processing, which reduces the impact of electric field non-uniformities.
While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.