Patent Application
20220351951
Aspects generally relate to substrate support apparatus and systems having elevated surfaces for heat transfer between the elevated surfaces and a substrate, and the methods of using the same. In one aspect, the elevated surfaces are disposed between a recessed surface and a plurality of support surfaces of a plurality of support protrusions that extend from the recessed surface. In one aspect, the elevated surfaces are disposed between a base surface and a plurality of support surfaces of a plurality of support protrusions that extend from the base surface.
During processing of substrates, temperature non-uniformity can occur within the substrates. For example, areas of the substrate that are above lift pin openings (and adjacent thereto) can be cooler than other areas of the substrate due. The cooler areas can result from less heat transfer to the substrate relative to the other areas, and heat loss through lift pins and the lift pin openings.
Attempts to address the temperature non-uniformity have failed and have resulted in other concerns, such as component breakage. Moreover, the temperature non-uniformity can involve problems such as deposition non-uniformity, reduced throughput, increased costs, and more complex downstream processing.
Therefore, there is a need for improved apparatus, methods, and systems that facilitate one or more of enhanced temperature uniformity during substrate processing, reduced likelihood of component breakage, increased throughput, reduced costs, and less complex downstream processing.
Aspects generally relate to substrate support apparatus and systems having elevated surfaces for heat transfer between the elevated surfaces and a substrate, and the methods of using the same. In one aspect, the elevated surfaces are disposed between a recessed surface and a plurality of support surfaces of a plurality of support protrusions that extend from the recessed surface. In one aspect, the elevated surfaces are disposed between a base surface and a plurality of support surfaces of a plurality of support protrusions that extend from the base surface.
In one implementation, a substrate support apparatus includes a support body. The support body includes a substrate support face. The substrate support face includes an outer support surface, a recessed surface disposed inwardly of the outer support surface, and a plurality of support protrusions extending from the recessed surface. The plurality of support protrusions have a plurality of support surfaces. The support body incudes a plurality of pin openings configured to received lift pins therein, and a plurality of elevated surfaces disposed between the recessed surface and the plurality of support surfaces. Each elevated surface of the plurality of elevated surfaces is disposed about a respective pin opening of the plurality of pin openings.
In one implementation, a substrate support apparatus includes a support body. The support body includes a substrate support face. The substrate support face includes a base surface and a plurality of support protrusions extending from the base surface. The plurality of support protrusions have a plurality of support surfaces. The support body includes a plurality of pin openings configured to received lift pins therein, and a plurality of elevated surfaces disposed between the base surface and the plurality of support surfaces. Each elevated surface of the plurality of elevated surfaces is disposed about a respective pin opening of the plurality of pin openings
In one implementation, a method of processing substrates includes positioning a substrate on one or more support surfaces of a substrate support apparatus disposed in a processing chamber. The positioning includes moving the substrate support apparatus relative to a plurality of lift pins disposed in a plurality of pin openings of the substrate support apparatus. The method includes conducting a substrate processing operation on the substrate. The substrate processing operation includes heating the substrate support apparatus, and transferring heat to the substrate through a plurality of cavities positioned between the substrate and a plurality of elevated surfaces. The plurality of elevated surfaces are disposed between the one or more support surfaces and one or more recessed surfaces of the substrate support apparatus. Each elevated surface of the plurality of elevated surfaces is disposed about a respective pin opening of the plurality of pin openings.
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 scope, as the disclosure 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.
Aspects generally relate to substrate support apparatus and systems having elevated surfaces for heat transfer between the elevated surfaces and a substrate, and the methods of using the same. In one aspect, the elevated surfaces are disposed between a recessed surface and a plurality of support surfaces of a plurality of support protrusions that extend from the recessed surface. In one aspect, the elevated surfaces are disposed between a base surface and a plurality of support surfaces of a plurality of support protrusions that extend from the base surface.
The processing chamber 100 includes a chamber body 102, a pedestal 104 disposed within the chamber body 102, and a lid assembly 106 coupled to the chamber body 102 and enclosing the pedestal 104 in a processing volume 120. The lid assembly 106 includes a gas distributor 112. A substrate 107 is provided to the processing volume 120 through an opening 126 formed in the chamber body 102.
An isolator 110, which may be a dielectric material such as a ceramic or metal oxide, for example aluminum oxide and/or aluminum nitride, separates the gas distributor 112 from the chamber body 102. The gas distributor 112 includes openings 118 for admitting process gases into the processing volume 120. The process gases may be supplied to the processing chamber 100 via a conduit 114, and the process gases may enter a gas mixing region 116 prior to flowing through the openings 118. An exhaust 152 is formed in the chamber body 102 at a location below the pedestal 104. The exhaust 152 may be connected to a vacuum pump (not shown) to remove unreacted species and by-products from the processing chamber 100.
The gas distributor 112 may be coupled to an electric power source 141, such as an RF generator or a DC power source. The DC power source may supply continuous and/or pulsed DC power to the gas distributor 112. The RF generator may supply continuous and/or pulsed RF power to the gas distributor 112. The electric power source 141 is turned on during the operation to supply an electric power to the gas distributor 112 to facilitate formation of a plasma in the processing volume 120.
The pedestal 104 may be formed from a ceramic material, for example a metal oxide or nitride or oxide/nitride mixture such as aluminum, aluminum oxide, aluminum nitride, or an aluminum oxide/nitride mixture. The pedestal 104 is supported by a shaft 143. The pedestal 104 may be grounded. One or more heaters 128 are embedded in the pedestal 104. The one or more heaters 128 (one is shown) are one or more resistive heaters. The heater 128 may be a plate, a perforated plate, a mesh (such as a wire mesh), a wire screen, or any other distributed arrangement. The heater 128 is coupled to an electric power source 132 via a connection 130. The electric power source 132 may be a power supply that controls the heater 128. The electric power source 132 supplies electric power (such as an alternating current) to the heater 128 to generate heat. One or more cooling channels 180 can be formed in the pedestal 104 to cool the substrate 107. The one or more cooling channels 180 receive a cooling fluid to cool the substrate 107.
The pedestal 104 includes an electrode 136 and an electric power source 138 electrically coupled to the electrode 136. The electrode 136 may be a plate, a perforated plate, a mesh (such as a wire mesh), a wire screen, or any other distributed arrangement. The electric power source 138 is configured to supply a chucking voltage and/or RF power to the electrode 136 through the electrode 136. Using the electrode 136, the pedestal 104 is as an electrostatic chuck that chucks the substrate 107 thereto. Using the electrode 136, the electric power source 138 may be utilized to control properties of the plasma formed in the processing volume 120, or to facilitate generation of the plasma within the processing volume 120. For example, the electric power source 141 and the electric power source 138 may be tuned to two different frequencies to promote ionization of multiple species in the processing volume 120. The electric power source 141 and the electric power source 132 may be utilized to generate a capacitively-coupled plasma within the processing volume 120.
The pedestal 104 includes a substrate support face 142 for supporting the substrate 107. The pedestal 104 may also include a step 140 having a pocket 144. The step 140 may be an edge ring. The substrate 107 and the step 140 may be concentrically disposed on the substrate support face 142 of the pedestal 104. The step 140 can be integrally formed with the pedestal 104.
The pedestal 104 can be at least a part of a substrate support apparatus coupled to the shaft 143. The pedestal 104 can include a single support body, or can include a plurality of bodies, such as a top plate (a support body) having the substrate support face 142 mounted to a base plate, where the base plate is mounted to the shaft 143.
The processing chamber 100 is a part of a system 101 for processing substrates. The system 101 includes a controller 190 to control the operations of the system 101. The controller 190 includes a central processing unit (CPU) 191, a memory 192 containing instructions, and support circuits 193 for the CPU 191. The controller 190 controls the system 101 directly, or via other computers and/or controllers (not shown) coupled to the system 101. The controller 190 is of any form of a general-purpose computer processor that is used in an industrial setting for controlling various chambers and equipment, and sub-processors thereon or therein.
The memory 192, or non-transitory computer readable medium, is one or more of a readily available memory such as random access memory (RAM), read only memory (ROM), floppy disk, hard disk, flash drive, or any other form of digital storage, local or remote. The support circuits 193 are coupled to the CPU 191 for supporting the CPU 191 (a processor). The support circuits 193 include cache, power supplies, clock circuits, input/output circuitry and subsystems, and the like. Substrate processing parameters and operations are stored in the memory 192 as a software routine that is executed or invoked to turn the controller 190 into a specific purpose controller to control the operations of the system 100. The controller 190 is configured to conduct any of the methods and operations described herein. The instructions stored in the memory 192, when executed, cause one or more of operations 502-506 of method 500 to be conducted.
As an example, the instructions stored in the memory 192, when executed, cause the electric power source 132 to change a heated temperature of the one pedestal 104 using the one or more heaters 128. The system 101 can include one or more sensors 195 to measure temperatures of different zones of the substrate 107 during a substrate processing operation. As an example, the one or more sensors 195 can measure first temperatures of zones of the substrate 107 aligned vertically above the cavities 263 and the elevated surfaces 240 described below and second temperatures of zones of the substrate 107 aligned outside of the cavities 263 and the elevated surfaces 240.
The plurality of instructions executed by the controller 190 include instructions that instruct the one or more sensors 195 conduct the measurements. The one or more sensors 195 can alternatively or additionally measure properties of the substrate 101, such as film thickness and/or film uniformity. The one or more sensors 195 include one or more particle counters, metrology sensors, on-substrate spectroscopy sensors (such as X-ray fluorescence spectroscopy (XRF) sensors and/or X-ray photoelectron spectroscopy (XPS) sensors), cameras, and/or optical sensors (such as laser sensors). Sensors outside of the processing chamber 100, such as sensors coupled to a second chamber (for example a measurement chamber, a load lock chamber, a transfer chamber, a buffer chamber, an interface chamber, or a factory interface chamber), which are similar to the sensors 195 can also measure the properties of the substrate 101.
The controller 190 can determine differences between the first temperatures and the second temperatures. If the differences exceed a threshold, the controller 190 can output an alert and/or adjust a heated temperature for the pedestal 104. The alert can instruct an operator to replace the pedestal 104 (such as a support body of the pedestal 104). The instructions in the memory 192 of the controller 190 can include one or more machine learning/artificial intelligence algorithms that can be executed in addition to the operations described herein. As an example, a machine learning/artificial intelligence algorithm executed by the controller 190 can optimize and alter operational parameters (such as the heated temperature for the pedestal 104) based on the temperature measurements and/or the substrate property measurements taken by the one or more sensors 195 and/or the sensors coupled to the second chamber. The machine learning/artificial intelligence algorithm can also output the alert. The machine learning/artificial intelligence algorithm can account for stored data collected during previous iterations of substrate processing operations.
The substrate support apparatus 201 includes a support body 204. The support body 204 shown in
Each of the support protrusions 210 is a support post (e.g., a support mesa). Each of the plurality of support protrusions 210 are shown as being rectangular in shape in plan view. The present disclosure contemplates that the support protrusions 210 may be circular, oval, hexagonal, or other shape in plan view.
A plurality of pin openings 212 (three are shown in
The support body 204 includes a plurality of elevated surfaces 240 (three are shown in
A circular gap 261 can be disposed about each cylindrical gap 260 and between the respective cylindrical gap 260 and adjacent support protrusions 210. As shown in
The plurality of support surfaces 215 are disposed at a first height H1 relative to the recessed surface 245, and the plurality of elevated surfaces 240 are disposed at a second height H2 relative to the recessed surface 245. The second height H2 is less than the first height H1. The recessed surface 245 can be referred to as a base surface of the support body 204. The second height H2 is a fraction F1 of the first height H1. In one embodiment, which can be combined with other embodiments, the fraction F1 is within a range of 0.3 to 0.8. Each of the first height H1 and the second height H2 is within a range of 5 microns to 75 microns. In one embodiment, which can be combined with other embodiments, the first height H1 is within a range of 25 microns to 35 microns, and the second height H2 is within a range of 7 microns to 24 microns. In one embodiment, which can be combined with other embodiments, the second height H2 is within a range of 25 microns to 35 microns, and the first height H1 is within a range of 40 microns to 50 microns. In one embodiment, which can be combined with other embodiments, a difference between the first height H1 and the second height H2 is within a range of 10 microns to 20 microns. In one embodiment, which can be combined with other embodiments, the recessed surface 245 of an Ra that is greater than an Ra of the support surfaces 215 of each of the support protrusions 210. In one example, which can be combined with other examples, the Ra of the recessed surface 245 is about 63 micro inches.
The substrate support 204 can be a part of the pedestal 104, such as a top plate that is mounted to a base plate of the pedestal 104. The base plate is coupled to the shaft 143.
The substrate 107 is positioned on and supported on the outer support surface 202 and the plurality of support surfaces 215 for a substrate processing operation. Cavities 263 are disposed between the elevated surfaces 240 and a backside surface of the substrate 107. A plenum 264 is disposed between the recessed surface 245 and the backside surface of the substrate 107. The cavities 263 have a cavity depth (between the respective elevated surface 240 and the substrate 107) and the cavity depth is less than a plenum depth (between the recessed surface 245 and the substrate 107) of the plenum 264. During the substrate processing operation, the substrate 107 is heated using the support body 204, and the heat is conducted to the substrate 107 through the support protrusions 210. The heat is also radiated and conducted through the plenum 264 from the recessed surface 245. The support body 204 includes one or more vacuum openings 267 (one is shown in
Additionally, the heat is radiated and conducted through the cavities 263 from the elevated surfaces 240, from the tapered surfaces 257, and from the lift pins 231. The heat transferred through the cavities 263 is increased by having elevated surfaces 240 at the second height H2 that is less than the first height H1. The cavities 263 have a cavity depth that is equal to the first depth D1 described below. The plenum 254 has a plenum depth that is equal to the second depth D2 described below. Using the cavity depth of the cavities 263 that is shorter than the plenum depth of the plenum 264 facilitates increasing heat transfer through the cavities 263 relative to the plenum 264. Increasing the heat transferred through the cavities 263 relative to the plenum 264 facilitates increasing a temperature of zones of the substrate 107 that are vertically aligned with the cavities 263.
Increasing the temperature of the zones vertically aligned above the cavities 263 facilitates more uniform temperatures as compared to zones of substrate 107 that are aligned outside of the cavities 263. Otherwise, the temperature of the zones aligned above cavities 263 can be a difference DIFF of 10 degrees Celsius (or more) lower than the zones aligned outside of the cavities 263. The difference DIFF can be 1% or more of the temperature of the zones aligned outside of the cavities 263. Using the elevated surfaces 240 and the cavities 263, the difference DIFF is less than 1%, such as less than 0.5%. Accordingly, the second height H2 of the elevated surfaces 240 facilitates maintaining temperature uniformity during heating of the substrate 107 even when heat is lost through the lift pins 231 and the pin openings 212. The lost heat would otherwise cause zones of the substrate 107 above the cavities 263 to be heater to a temperature that is less than other zones of the substrate 107, causing non-uniform deposition thereon during a deposition process, such as a CVD process or a PECVD process. The second height H2 of the elevated surfaces 240 facilitates uniform film deposition.
Referring to
Using a first mask pattern 320 placed on the support body 204 In
The first bead blasting operation is conducted to a first depth D1 that is equal to the second height H2 subtracted from the first height H1. The first bead blasting operation removes material to form the elevated surfaces 240.
As shown in
The present disclosure contemplates that other mechanical polishing operations such as wet abrasive blasting and micro-blasting can be used in place of the first bead blasting operation and the second bead blasting operation.
As shown in
The substrate support apparatus 401 includes a support body 404. The support body 404 includes a substrate support face 442. The substrate support face 442 includes a base surface 445, and a plurality of support protrusions 410 extending from the base surface 445. The plurality of support protrusions 410 have a plurality of support surfaces 415. The support body 404 also includes a ledge 426. In one embodiment, which can be combined with other embodiments, the ledge 426 includes an outer support surface 427 disposed outwardly of and peripherally around the base surface 445 and the support protrusions 410. In one embodiment, which can be combined with other embodiments, the base surface 445 is a recessed surface that is recessed relative to the outer support surface 427 and the support protrusions 410. The support body includes the plurality of pin openings 212 configured to received the lift pins 231 therein. The plurality of elevated surfaces 240 are disposed between the base surface 445 and the plurality of support surfaces 415. The substrate 107 is supported on the outer support surface 427 and the support surfaces 415 during the substrate processing operation.
As shown in
The support protrusions 410 can be disposed along the base surface 445 in a uniform arrangement or a non-uniform arrangement. The support protrusions 410 may be disposed along the base surface 445 in any suitable arrangement, for example, concentric circles or hexagonal arrangements. The number (e.g. density) and dimensions of the support protrusions 410 may be selected to improve electrostatic chucking of substrates. In one embodiment, which can be combined with other embodiments, the support protrusions 410 have a surface roughness within a range of 1 Ra to 64 Ra.
The support protrusions 410 each have a diameter DA1 within a range of 0.25 mm to 2.5 mm. The support surfaces 415 of the support protrusions 410 are formed at the first height H1 relative to the base surface 445. The first height H1 is the same as a height of the outer support surface 327 of the ledge 416. The present disclosure contemplates that the first height H1 of the support protrusions 410 can be greater or less than the height of the outer support surface 327 of the ledge 226. The second height H2 of the elevated surfaces 240 is relative to the base surface 445. A distance between individual support protrusions 410 is within a range of 0.1 mm to 3 mm. A ratio of the distance between individual support protrusions 410 and a diameter of the base surface 445 is within a range of 0.01 to 0.2, such as within a range of 0.05 to 0.15, for example 0.1.
The method 500 includes conducting a substrate processing operation on the substrate. The substrate processing operation can include a deposition operation such as a CVD operation or a PECVD operation. The substrate processing operation can include an etching operation, an oxidation operation, an anneal operation, and/or an ion implantation operation.
The substrate processing operation includes, at operation 504, heating the substrate support apparatus. The substrate support apparatus is heated to a temperature within a range of 500 degrees Celsius to 560 degrees Celsius. The present disclosure contemplates that operation 504 may include cooling (e.g., dissipating heat from) the substrate support apparatus in place of or in addition to the heating of the substrate support apparatus.
The substrate processing operation includes, at operation 506, transferring heat to the substrate (from the substrate support apparatus) through a plurality of cavities positioned between the substrate and a plurality of elevated surfaces. The plurality of elevated surfaces are disposed between the one or more support surfaces and one or more recessed surfaces of the substrate support apparatus. The present disclosure also contemplates that operation 506 may include—in place of or in addition to the transferring heat to the substrate—transferring heat to the substrate support apparatus (from the substrate) through the plurality of cavities.
One or more of the operations 502-506 can be repeated. According to one implementation, heating can occur at operation 504, then heat can be transferred to the substrate at operation 506, then cooling can occur at operation 504, and then heat can be transferred to the substrate support apparatus at operation 506.
Each elevated surface of the plurality of elevated surfaces is disposed about a respective pin opening of the plurality of pin openings. In one embodiment, which can be combined with other embodiments, the one or more support surfaces are part of a plurality of support posts extending from the one or more recessed surfaces. The one or more support surfaces are disposed at the first height H1 relative to the one or more recessed surfaces, and the plurality of elevated surfaces are disposed at the second height H2 relative to the one or more recessed surfaces. The second height H2 is less than the first height H1. In one embodiment, which can be combined with other embodiments, the one or more support surfaces are part of a plurality of raised dimples extending from the one or more recessed surfaces. The plurality of elevated surfaces are formed at the first depth D1 relative to the one or more support surfaces. The one or more recessed surfaces are formed at the second depth D2 relative to the one or more support surfaces. The second depth D2 is greater than the first depth D1.
The cylindrical bands 260 can be recessed below the single support surface 645, as shown in
Benefits of the present disclosure include at least enhanced and efficient temperature uniformity during substrate processing (such as efficient temperature uniformity during heating and/or cooling of the substrate), uniform film deposition on substrates, reduced likelihood of component breakage, increased throughput, reduced costs, and less complex
It is contemplated that one or more aspects disclosed herein may be combined. As an example, one or more aspects, features, components, and/or properties of the processing chamber 100, the substrate support apparatus 201, the method of making the substrate support apparatus 201 shown in relation to
The present disclosure achieves the aforementioned benefits over other operations that involve decreasing the size of lift pins and pin openings, and operations that involve increasing heat generated in areas of the heater that are adjacent the pin openings. For example, reducing the size of lift pins and pin openings involve breakage of the lift pins, resulting in machine downtime and replacement costs. As another example, increasing heat generated in areas of the heater that are adjacent the pin openings still involves temperature non-uniformity in zones of the substrate that are aligned above the lift pins and pin openings. Additionally, increasing the heat fails to account for non-uniformities during cooling of the substrate. Attempts have been made, but failed, to solve the problems of temperature non-uniformity. The present disclosure achieves unexpected results in reducing the temperature non-uniformity of the substrate as it was previously thought that using elevated surfaces 240 would complicate manufacturing.
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. The present disclosure also contemplates that one or more aspects of the embodiments described herein may be substituted in for one or more of the other aspects described. The scope of the disclosure is determined by the claims that follow.
