1. Field of Art
The present invention relates to a depositing apparatus for depositing one or more layers of materials on a substrate using atomic layer deposition (ALD).
2. Description of the Related Art
An atomic layer deposition (ALD) is a thin film deposition technique for depositing one or more layers of material on a substrate. ALD uses two types of chemical, one is a source precursor and the other is a reactant precursor. Generally, ALD includes four stages: (i) injection of a source precursor, (ii) removal of a physical adsorption layer of the source precursor, (iii) injection of a reactant precursor, and (iv) removal of a physical adsorption layer of the reactant precursor. ALD can be a slow process that can take an extended amount of time or many repetitions before a layer of desired thickness can be obtained. Hence, to expedite the process, a vapor deposition reactor with a unit module (so-called a linear injector), as described in U.S. Patent Application Publication No. 2009/0165715 or other similar devices may be used to expedite ALD process. The unit module includes an injection unit and an exhaust unit for a source material (a source module), and an injection unit and an exhaust unit for a reactant (a reactant module).
A conventional ALD vapor deposition chamber has one or more sets of reactors for depositing ALD layers on substrates. As the substrate passes below the reactors, the substrate is exposed to the source precursor, a purge gas and the reactant precursor. The source precursor molecules deposited on the substrate reacts with reactant precursor molecules or the source precursor molecules are replaced with the reactant precursor molecules to deposit a layer of material on the substrate. After exposing the substrate to the source precursor or the reactant precursor, the substrate may be exposed to the purge gas to remove excess source precursor molecules or reactant precursor molecules from the substrate.
Embodiments relate to a radical reactor in a reactor assembly that includes a body placed adjacent to a susceptor on which the substrate is mounted. The body is formed with a first plasma chamber in a first reactor section extending for a first distance along the length of the radical reactor and a second plasma chamber in a second reactor section extending for a second distance along the length of the radical reactor. A first inner electrode extends within the first plasma chamber. The first inner electrode generates the radicals of a first gas within the first plasma chamber by applying a voltage difference across the first inner electrode and a first outer electrode. A second inner electrode extends within the second plasma chamber. The second inner electrode generates the radicals of the first gas within the second plasma chamber by applying the voltage difference across the second inner electrode and a second outer electrode.
In one embodiment, the body is further formed with an injection chamber, a constriction zone and at least one outlet. The injection chamber is connected to the first plasma chamber and the second plasma chamber to receive the radicals. The radicals are injected onto the substrate from the injection chamber. The constriction zone has a height lower than the height of the injection chamber. At least one outlet is connected to the construction zone. The at least one outlet discharges the radicals from the reactor assembly.
In one embodiment, the first plasma chamber is formed at one side of the injection chamber and the second plasma chamber is formed at the other side of the injection chamber.
In one embodiment, the body is further formed with a first reactor channel in the first reactor section and a second reactor channel in the second reactor section. The first reactor channel is connected to a gas source via a first conduit, and the second reactor channel is connected to the gas source via a second conduit separate from the first conduit.
In one embodiment, the body is further formed with at least two outlets for discharging the radicals from the reactor assembly. The inner surfaces of the at least two outlets join between the outlets.
In one embodiment, the reactor assembly further includes an injector formed with a first injector channel, a second injector channel, a chamber and a constriction zone. The first injector channel is placed in a first injector section of the injector for receiving a second gas via a first conduit. The second injector channel is placed in a second injector section of the injector receiving the second gas via a second conduit. A chamber is connected to the first injector channel and the second injector channel for receiving the gas and injecting the gas onto the substrate, at least one outlet for discharging the gas from the reactor assembly, and a constriction zone connecting the chamber to the at least one outlet. The constriction zone has a height lower than a height of the injection chamber.
In one embodiment, the first injector channel is formed at one side of the injector chamber and the second injector channel is formed at the opposite sided of the chamber.
In one embodiment, the effective length of the reactor assembly is greater than the width of the substrate.
In one embodiment, the first inner electrode includes a core and an outer layer. The core is made of a first material having a higher conductivity compared to a second material of the outer layer.
In one embodiment, the first material comprises copper, silver or alloy thereof; and the second material comprises stainless steel, austenitic nickel-chromium-based superalloy or nickel steel alloy.
Embodiments also relate to a deposition apparatus for depositing one or more layers of material on a substrate using atomic layer deposition (ALD). The deposition apparatus includes a susceptor, a radical reactor and an actuator. The susceptor is mounted with a substrate. The radical reactor includes a body placed adjacent to the susceptor. The body is formed with a first plasma chamber in a first reactor section of the radical reactor extending lengthwise for a first distance and a second plasma chamber in a second reactor section extending lengthwise for a second distance. A first inner electrode extends within the first plasma chamber. The first inner electrode generates the radicals of a first gas within the first plasma chamber by applying a voltage difference across the first inner electrode and a first outer electrode. A second inner electrode extends within the second plasma chamber. The second inner electrode generates the radicals of the first gas within the second plasma chamber by applying the voltage difference across the second inner electrode and a second outer electrode. The actuator causes relative movement between the susceptor and the radical reactor.
Embodiments are described herein with reference to the accompanying drawings. Principles disclosed herein may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. In the description, details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the features of the embodiments.
In the drawings, like reference numerals in the drawings denote like elements. The shape, size and regions, and the like, of the drawing may be exaggerated for clarity.
Embodiments relate to an elongated reactor assembly in a deposition device for performing atomic layer deposition (ALD) on a wide substrate. The elongated reactor assembly includes one or more injectors and/or radical reactors. As part of the ALD process, each injector or radical reactor injects a gas or radicals onto the substrate as the substrate passes the injector or radical reactor. Each injector or radical reactor includes a plurality of sections where at least two sections have different cross sectional configurations. Different sections receive the gas via different conduits (e.g., pipes). By providing different sections in the injector or radical reactor, the injector or radical reactor may inject the gas or the radicals more uniformly over the substrate. Each injector or radical reactor may include more than one outlet for discharging excess gas or radicals outside the deposition device.
Figure (
The process chamber enclosed by the walls 110 may be maintained in a vacuum state to prevent contaminants from affecting the deposition process. The process chamber contains a susceptor 128 which receives a substrate 120. The susceptor 128 is placed on a support plate 124 for a sliding movement. The support plate 124 may include a temperature controller (e.g., a heater or a cooler) to control the temperature of the substrate 120. The linear deposition device 100 may also include lift pins (not shown) that facilitate loading of the substrate 120 onto the susceptor 128 or dismounting of the substrate 120 from the susceptor 128.
In one embodiment, the susceptor 128 is secured to brackets 210 that move across an extended bar 138 with screws formed thereon. The brackets 210 have corresponding screws formed in their holes receiving the extended bar 138. The extended bar 138 is secured to a spindle of a motor 114, and hence, the extended bar 138 rotates as the spindle of the motor 114 rotates. The rotation of the extended bar 138 causes the brackets 210 (and therefore the susceptor 128) to make a linear movement on the support plate 124. By controlling the speed and rotation direction of the motor 114, the speed and direction of the linear movement of the susceptor 128 can be controlled. The use of a motor 114 and the extended bar 138 is merely an example of a mechanism for moving the susceptor 128. Various other ways of moving the susceptor 128 (e.g., use of gears and pinion at the bottom, top or side of the susceptor 128) may be used. Moreover, instead of moving the susceptor 128, the susceptor 128 may remain stationary and the reactor assembly 136 may be moved.
One or more of the reactors 320, 334, 364, 368 are connected to gas pipes via inlet 330 to receive source precursor, reactor precursor, purge gas and/or other materials. The materials provided by the gas pipes may be (i) injected onto the substrate 314 directly by the reactors 320, 334, 364, 368, (ii) after mixing in a chamber inside the reactors 320, 334, 364, 368, or (iii) after conversion into radicals by plasma generated within the reactors 320, 334, 364, 368. After the materials are injected onto the substrate 314, the redundant materials may be exhausted through outlets 330.
Embodiments of reactor assembly described herein can be used in deposition devices such as the linear deposition device 100, the rotating deposition device 300 or other types of deposition devices.
The injector 402 receives gas through pipes (e.g., pipe 424, and pipe 512 illustrated in
The radical reactor 404 receives gases via pipes (not shown) and has two sections with different cross sectional configurations and separate inner electrodes. Channels are formed in the body of the radical reactor 404 to convey the received gases to the plasma chambers. Two inner electrodes extend approximately halfway across the radical reactor 404 and are connected to a voltage source (not shown) or ground (not shown) via wires 432. The inner electrodes are placed inside plasma chambers, as described below in detail with reference to
As illustrated in
Similarly, the radical reactor 404 has two reactor sections 505, 507 with different cross sectional configurations. The body 606 (see
As for the radical reactor 404, the radical reactor 404 has a body 606 with outlets 416, 420 formed thereon. The outlets 416, 420 are cavities adjoining at a center section of the body 606. The bottom part 618 of the outlets 416, 420 extends substantially across the length of the radical reactor 404 while the upper parts 612, 614 of the outlets 416, 420 are smaller for connection to discharge pipes. The outlets 416 and 420 have contoured inner surfaces 640, 644 that join smoothly around the middle of the radical reactor 404.
As the length of the injector 402 or radical reactor 404 increases, vacuum conductivity within the injector 402 or the radical reactor 404 may be decreased. The decrease in the vacuum conductivity results in decreased efficiency in discharging the gases or radicals remaining in the injector 402 or radical reactor 404. By providing multiple outlets, the vacuum conductivity can be enhanced. This contributes to more efficient discharge of the gases or radicals from the injector 402 or the radical reactor 404.
Although only two outlets are formed in the injector 402 and the radical reactor 404, more than two outlets can be formed in the injector 402 and the radical reactor 404 depending on the length of the injector 402 or the radical reactor 404.
During the operation of the radical reactor 404, the gas is injected into channels 510, 518 via pipes 714A, 714B. The gas flows into the plasma chamber 718, 720 via holes 540, 544. Plasma is generated in the plasma chamber 718, 720, resulting in radicals of the gas. The radicals are then injected via the slits 734, 738 into the injection chamber 560 formed on the bottom part of the radical reactor 404.
Similarly, the channel 510, the holes 540, the plasma chamber 718 and the inner electrode 504 are aligned along plane G-G″. Plane G-G″ is slanted at an angle of β with respect to the vertical plane G-G′. The angle α and the angle β may have an identical or different amplitude.
The gas injected into the plasma chamber 718 via the channel 510 and the holes 540 are converted into radicals by applying a voltage difference across the inner electrode 504 and an outer electrode 820. The generated radicals travel via the slit 734 into the injection chamber 560. Within the injection chamber 560, the radicals move towards the substrate 120, and come into contact with the substrate 120. The radicals may function as a source precursor, a reactant precursor or as surface treating material on the substrate 120. The remaining radicals (and/or gases reverted to an inactive state) pass a constriction zone 844 and are discharged via the outlet 420.
The channel 518, the holes 544, the plasma chamber 720 and the inner electrode 432 are aligned along plane I-I″. Plane I-I″ is slanted at an angle of β′ with respect to the vertical plane I-I′. Within the injection chamber 560, the radicals move towards the substrate 120, and come into contact with the substrate 120. The radicals may function as a source precursor, a reactant precursor or as surface treating material on the substrate 120. The remaining radicals (and/or gases reverted to an inactive state) pass a constriction zone 844 and are discharged via the outlet 420. The angle α′ and the angle β′ may be of identical or different amplitude.
Embodiments described above with reference to
(the left and the right sides) of the injector or radical reactor instead of being provided only on one side (e.g., the right side as illustrated in
In one embodiment, the reactor assembly deposits a layer of Al2O3 on the substrate 120 by having the injector 402 inject Trimethylaluminium (TMA) onto the substrate 120 as a source precursor and the radical reactor 404 inject radicals of N2O or O2 as a reactant precursor onto the substrate. Various other materials may be used as source precursors and reactant precursors to deposit other materials on the substrate.
The radical reactor of
Depending on the size and the use of the reactor assembly, its injectors or radical reactors may be divided into more than three sections. The sections need not be of an equal length, and the sections of the injectors and the radical reactors may have different lengths. In one embodiment, the total lengths of the injectors and the radical reactors are different. Further, the injectors and the radical reactors need not be placed and tandem, and can be placed remotely from each other.
Although the present invention has been described above with respect to several embodiments, various modifications can be made within the scope of the present invention. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.
This application claims priority under 35 U.S.C. §119(e) to co-pending U.S. Provisional Patent Application No. 61/416,931, filed on Nov. 24, 2010, which is incorporated by reference herein in its entirety.
Number | Date | Country | |
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61416931 | Nov 2010 | US |