SYSTEMS FOR PLASMA ENHANCED CHEMICAL VAPOR DEPOSITION AND BEVEL EDGE ETCHING
Embodiments described herein relate to a substrate processing system that integrates substrate edge processing capabilities. Illustrated examples of the processing system include, without limitations, a factory interface, a loadlock chamber, a transfer chamber, and one or more twin process chambers having two or more processing regions that are isolatable from each other and share a common gas supply and a common exhaust pump. The processing regions in each twin process chamber include separate gas distribution assemblies and RF power sources to provide plasma at selective regions on a substrate surface in each processing region. Each twin process chamber is thereby configured to allow multiple, isolated processes to be performed concurrently on at least two substrates in the processing regions.
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This application is a continuation of co-pending U.S. patent application Ser. No. 12/106,881, filed Apr. 21, 2008 (Attorney Docket No. 11997), which claims the benefit of U.S. Provisional Patent Applications Ser. No. 60/949,397 (Attorney Docket No. 011997L), filed Jul. 12, 2007, Ser. No. 60/982,961 (Attorney Docket No. 011997L02), filed Oct. 26, 2007, and Ser. No. 60/982,993 (Attorney Docket No. 011997L03), filed Oct. 26, 2007. All aforementioned patent applications are herein incorporated by reference.
BACKGROUND OF THE INVENTION1. Field of the Invention
Embodiments of the invention generally relate to apparatus and methods for processing semiconductor substrates. More particularly, embodiments of the present invention relate to apparatus and methods for processing a substrate near an edge region.
2. Description of the Related Art
To reduce the cost of ownership, semiconductor manufacture processes may be performed in an integrated system that is capable of processing multiple substrates in parallel with high repeatability. The integrated system usually comprises a factory interface, a loadlock chamber and a substrate deposition chamber adapted to form a deposition film on one or more substrates by chemical vapor deposition (CVD) or plasma enhanced chemical vapor deposition (PECVD) processes.
During the CVD/PECVD process, it is usually desirable to have a uniform thickness profile across a substrate and no deposition near an edge area of the substrate. The area near the edge where deposition is not desired is generally referred to as the “edge exclusion.”
To prevent the formation of the deposition film at the edge of the substrate,
While the use of the shadow ring 105 can currently achieve thickness uniformity, or other desired edge profile, within up to a 3.5 mm-wide edge exclusion area, the requirement for thickness non-uniformity, or other desired profile characteristics, has to be reduced to a 2 mm-wide edge exclusion area owing to increasingly shrinking device dimensions. As a result of the smaller edge exclusion area, the conventional approach using the shadow ring 105 to prevent deposition at the edge area may not provide satisfactory result.
Therefore, there is a need for an apparatus and method for depositing a film on a substrate and removing the film from the substrate edge region in an integrated manner without using a shadow ring.
SUMMARY OF THE INVENTIONThe present application describes substrate processing apparatuses and methods that integrate substrate edge processing capabilities. In one embodiment, an apparatus comprises a loadlock chamber, a transfer chamber coupled to the loadlock chamber, and one or more twin process chamber coupled to the transfer chamber, each process chamber defining a plurality of separate processing regions. Each processing region comprises a substrate support having a substrate support surface, a plasma generator configured to supply an etching agent in a plasma phase to a peripheral region of the substrate support surface, and a gas delivery assembly coupled to a gas source, wherein the gas delivery assembly is configured to generate a radial gas flow over the substrate support surface, and the radial gas flow travels from an approximately central region of the substrate support surface toward the peripheral region of the substrate support surface.
In another embodiment, a substrate processing apparatus comprises a loadlock chamber, a transfer chamber coupled to the loadlock chamber, one or more twin process chamber coupled to the transfer chamber and adapted for implementing deposition processes, and a substrate edge processing chamber coupled to the transfer chamber. The substrate edge processing chamber comprises a substrate support having a substrate support surface, a plasma generator configured to supply an etching agent in a plasma phase to a peripheral region of the substrate support surface, and a gas delivery assembly coupled to a gas source, wherein the gas delivery assembly is configured to generate a radial gas flow over the substrate support surface, and the radial gas flow travels from an approximately central region of the substrate support surface toward the peripheral region of the substrate support surface.
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, 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 typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention 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 disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.
DETAILED DESCRIPTIONEmbodiments described herein relate to a substrate processing system that integrates substrate edge processing capabilities. More specifically, the processing system is operable to receive the load of one or more substrate, form a deposition film on each substrate, and etch a selective portion of the deposition film at an edge region of the substrate. Illustrated examples of the processing system comprises, without limitations, a factory interface, a loadlock chamber, a transfer chamber, and one or more twin process chambers having two or more processing regions that are isolatable from each other and share a common gas supply and a common exhaust pump. The processing regions in each twin process chamber include separate gas distribution assemblies and RF power sources to provide plasma at selective regions on a substrate surface in each processing region. Each twin process chamber is thereby configured to allow multiple, isolated processes to be performed concurrently on at least two substrates in the processing regions.
As shown in
Referring to
A substrate support assembly 330 may be centrally disposed within each processing region 302. In one embodiment, the support assembly 330 may be temperature controlled. The support assembly 330 may support a substrate 304 during processing. In one embodiment, the support assembly 330 comprises a support base 332 made of aluminum that may encapsulate at least one embedded heater 334 operable to controllably heat the support assembly 330 and the substrate 304 positioned thereon to a predetermined temperature. In one embodiment, the support assembly 330 may operate to maintain the substrate 304 at a temperature between about 150 degrees Celsius to about 1000 degrees Celsius, depending on the processing parameters for the material being processed.
Each support base 332 may have an upper side 336A and a lower side 336B. The upper side 336A that supports the substrate 304 has a surface area smaller than the substrate 304, so that a peripheral edge region of the substrate 304 remains free of contact with the support base 332 to facilitate its processing, such as etching, or cleaning. The lower side 336B may have a stem 338 coupled thereto. The stem 338 couples the support assembly 330 to a lift system 340 that moves the support assembly 330 vertically between an elevated processing position and a lowered position that facilitates substrate transfer to and from the processing region 302. The stem 338 additionally provides a conduit for electrical and thermocouple leads between the support assembly 330 and other components of the chamber 300. A bellows 342 may be coupled between the stem 338 and the bottom 314 of each processing region 202. The bellows 342 provides a vacuum seal between the process volume 316 and the atmosphere outside each processing region 302 while facilitating vertical movement of the support assembly 330.
To facilitate the transfer of the substrate 304, each support base 332 also has a plurality of openings 346 through which lift pins 348 are movably mounted. The lift pins 348 are operable to move between a first position and a second position. The first position, shown in
Each support assembly 330 may also comprise a centering mechanism 360 operable to center the substrate 304 relative to a vertical reference axis Z perpendicular to the substrate support plane of the support base 332. The centering mechanism 360 comprises three or more movable centering fingers 362 positioned at a periphery of the support base 332, and an opposing plate 364 placed below the fingers 362. Each finger 362 is pivotally mounted on the support base 332. The opposing plate 364 and the support base 332 are relatively movable so that the opposing plate 364 may contact and pivot the fingers 362 in a release position and stay free from the fingers 362 in a centering position.
In one embodiment, the opposing plate 364 may be stationary and the relative movement between the support base 332 and the opposing plate 364 is due to the vertical movement of the support base 332. The fingers 362 engage on the peripheral edge of the substrate 304 to center the substrate 304 when the support assembly 330 is in an elevated position as shown in
The lid assembly 322 provides an upper boundary to the process volume 316 in each processing region 302. The lid assembly 322 may be removed or opened to service the processing regions 302. In one embodiment, the lid assembly 322 may be fabricated from aluminum.
A gas delivery assembly is coupled to an interior side of the lid assembly 322 in each processing region 302. The gas delivery assembly includes a gas bowl 370 that is connected to a switchable power source 372 operable to selectively apply various potential biases to the gas bowl 370, including an RF potential bias, DC potential bias, AC potential bias, or ground potential. The gas bowl 370 has an outer wall 374, inner wall 376 and bottom 378. The shape of the bottom 378 may be configured to substantially follow the profile of the substrate 304 processed in each processing region 302. Each gas bowl 370 includes a first gas distribution circuit coupled to the first gas source 306 via the first entry port 307, and a second gas distribution circuit coupled to the second gas source 308 via the second entry port 309.
The first gas distribution circuit includes a first plenum 380A partially delimited between the outer wall 374, inner wall 376 and bottom 378, and a plurality of slits 382 formed through a peripheral region of the bottom 378 and connected to the first plenum 380A. In one embodiment, the slits 382 may be angled outwards to avoid gas flow toward a center portion of the substrate 304.
The second gas distribution circuit includes a plenum 380B that is surrounded by the first plenum 380A. The second plenum 380B, which is connected to the second entry port 309, is partially delimited between the inner wall 376 and a perforated portion 384 of the bottom 378. The perforated portion 384 includes a plurality of apertures 386 through which gases received in the plenum 380B flow into the process volume 316.
To etch a portion of a deposition film at an edge region of one substrate 304, each processing region 302 also includes a plasma generator that is disposed adjacent to the outer wall 374 for striking a plasma in a peripheral region of the substrate 304. The plasma generator includes an electrode 388 sandwiched between isolator materials 390, which are arranged adjacent to the outer wall 374 of the gas bowl 370. The electrode 388 is coupled to a RF power source 392, and includes a slant end 394 positioned proximate to the outer wall 374 and a peripheral portion of the support base 332.
Each of the processing region 302 configured as described above may be able to selectively operate in either a deposition mode or edge etching mode.
In a deposition mode of operation (such as PECVD), the plenum 380B receives a process gas from the second gas source 308, and the substrate 304 is heated. While the support assembly 330 is grounded, the switchable power source 372 applies an RF potential bias to the gas bowl 370, such that a plasma is generated from the process gas introduced through the apertures 386 into the process volume 316 between the support assembly 330 and the gas bowl 370. The entire substrate 304 is thereby exposed to the plasma for processing, for example for depositing a film on the substrate 304. The RF power from the switchable power source 372, the composition of the process gas, and the thermal conditions applied to the substrate 304 may be set in accordance with the type of deposition film to form on the substrate 304.
In one embodiment, the deposition film may include an advanced patterning film (“APF”) including amorphous carbon. The APF may be deposited at a substrate temperature between about 200° C. and 1500° C., while a process gas including propylene (C3H6) as carbon source is introduced in the process volume 316. Optionally, the process gas may include additional chemical elements to include in the APF, such as a nitrogen (N2) and doping elements. RF power from about 500W to about 1500W may be applied in the chamber at a frequency of about 13.56 MHz. A more detailed description of conditions for forming the APF by PECVD and its use is described in U.S. Pat. No. 7,262,106, entitled “Absorber Layer for DSA Processing”, which is incorporated herein by reference.
Once the formation of the deposition film is completed, the edge etching function may be used to remove undesirable portions of the deposition film in the edge region of the substrate 304. In an edge etching mode of operation, the first plenum 380A receives an etching gas from the first gas source 306 via the first entry port 307. Examples of etching gases may include, without limitation, NF3, O2, F2, or SF6. In the meantime, the gas bowl 370 and support base 332 may be grounded, such that RF power applied to the electrode 388 excites the etching gas introduced via the slits 382 in the vicinity between the slant end 394, the support base 332 and the gas bowl 370. The inclination angle of the slant end 394 may be set so as to facilitate the ionization of the etching gas delivered from the slits 382. An etching agent in a plasma phase is thereby formed in the vicinity of the edge region of the substrate 304.
To prevent the diffusion of the etching agent toward the central region of the substrate 304, the second gas source 308 provides an inert gas that is delivered via the second gas distribution circuit, and flows radially on the top surface of the substrate 304 from its central region toward its peripheral edge region. The radial flow of the inert gas allows to limit the action area of the etching agent to the peripheral region of the substrate 304.
While one specific implementation of the process system 300 has been illustrated above, variant embodiments may be possible. For example, alternate embodiments may define a plasma volume inside each processing region 302, but away from the substrate edge, such as integrated in the gas bowl 370. The plasma volume receives a flow of processing gas, which is excited as it passes between ground and RF electrodes placed in the plasma volume before it is delivered to the edge region of the substrate 304. In other embodiments, the plasma may be provided by a remote plasma source located outside each of the processing regions 302. Examples of similar processing systems for processing substrate edges are described U.S. Provisional Patent Application Ser. No. 60/982,993, entitled “APPARATUS AND METHOD FOR PROCESSING A SUBSTRATE EDGE REGION” (attorney docket No. 11997.L03), filed Oct. 26, 2007, which is herein incorporated by reference.
As has been described above, the processing system 200 is thus able to integrate substrate edge processing capabilities to process multiple substrates concurrently. While each twin process chamber of the processing system shown in
The twin process chamber 420 receives substrates that have been processed in the twin process chamber 410. The processed substrates have edge regions where portions of deposition films are to be etched away in the twin process chamber 420. A suitable structure for the twin process chamber 420 may be similar to the twin process chamber 300 illustrated in
In one embodiment, the processing system 200a may be operable to process a plurality of substrates by loading the substrates from the factory interface 210 into the loadlock chamber 240a. The substrate-handling robot 272 may then transfer the substrates from the loadlock chamber 240a into the twin process chamber 420 to undergo edge etching. After all the requisite semiconductor processes have been completed, the substrate-handling robot 272 may finally transfer the processed substrates out of the vacuum environment via the loadlock chamber 240b to the factory interface 210.
Each twin process chamber 410 is configured to implement CVD processes to form diverse deposition films on substrates. Each twin process chamber 410 may have two or more processing regions that are isolatable from each other and share a common gas supply and a common exhaust pump. The processing regions in each twin process chamber 410 include separate gas distribution assemblies and RF power sources to provide uniform plasma density over a substrate surface in each processing region. Each twin process chamber 410 is thereby configured to allow multiple, isolated processes to be performed concurrently on at least two substrates in the processing regions. Examples of twin process chambers adapted for deposition processes are disclosed in U.S. Pat. No. 5,855,681, entitled “ULTRA HIGH THROUGHPUT WAFER VACUUM PROCESSING SYSTEM”, which is incorporated herein by reference.
In one embodiment, the processing system 400 may be operable to process a plurality of substrates by loading the substrates from the factory interface 210 into the loadlock chamber 240a. The substrate-handling robot 272 may then transfer the substrates from the loadlock chamber 240a into one twin process chamber 410 to undergo one or more deposition processes. To remove undesirable portions of a deposition film formed at the edge region of the substrates, the substrate-handling robot 272 may transfer the processed substrates from one of the twin process chambers 410 to the twin process chamber 420 to undergo edge etching. After all the requisite semiconductor processes have been completed, the substrate-handling robot 272 may finally transfer the processed substrates out of the vacuum environment via the loadlock chamber 240b to the factory interface 210.
In one embodiment, the edge etching chamber 430 and the loadlock chamber 240 may be vertically stacked together similar to an edge etch-load lock combo shown in
Referring again to
It is worth noting that the edge etching chamber may be configured to process two or more substrates in parallel.
In alternate embodiments, the substrate edge etching function may also be more simply provided in the form of an edge etching apparatus comprised of a factory interface and a standalone edge etching chamber, as illustrated in
In
In
As has been described above, the processing systems and methods described herein are thus able to integrate substrate edge processing capabilities to process multiple substrates concurrently. High throughput processing combined with substrate edge processing capabilities thus can be advantageously achieved.
While the foregoing is directed to certain embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
Claims
1. An apparatus for processing multiple substrates, comprising:
- a loadlock chamber;
- a transfer chamber coupled to the loadlock chamber;
- one or more twin process chambers coupled to the transfer chamber; and
- a substrate edge processing chamber coupled to the transfer chamber, the substrate edge processing chamber comprising: a substrate support having a substrate support surface; and a gas distribution bowl disposed over the substrate support, wherein the gas distribution bowl comprises: an outer wall; and a bottom, wherein a plurality of slits are formed near a peripheral region of the bottom, the plurality of slits are configured to deliver a processing gas towards an edge region of the substrate support surface.
2. The apparatus of claim 1, wherein the gas distribution bowl is connected to a remote plasma source, and configured to distribute a plasma from the remote plasma source to the edge region of the substrate support surface.
3. The apparatus of claim 2, wherein the substrate edge processing chamber is disposed between the transfer chamber and a factory interface.
4. The apparatus of claim 3, further comprising a load lock chamber disposed between the transfer chamber and the factor interface, wherein the substrate edge processing chamber and the load lock chamber are vertically stacked together.
5. The apparatus of claim 4, wherein the substrate edge processing chamber further comprising:
- a first slit valve door adapted to connect with the factory interface; and
- a second slit valve door adapted to connect with the transfer chamber.
6. The apparatus of claim 3, further comprising a load lock chamber disposed between the transfer chamber and the factor interface, wherein the substrate edge processing chamber and the load lock chamber are arranged side by side.
7. The apparatus of claim 3, wherein the substrate edge processing chamber comprises a chamber body assembly defining a first processing region and a second processing region, the first and second processing regions are vertically stacked together, the substrate support and the gas distribution bowl are disposed in the first processing region, and the substrate edge processing chamber further comprises:
- an additional substrate support disposed in the second processing region; and
- an additional gas distribution bowl disposed over the additional substrate support in the second processing region, wherein the additional gas distribution bowl comprises: an outer wall; and a bottom, wherein a plurality of slits are formed near a peripheral region of the bottom, the plurality of slits are configured to deliver a processing gas towards an edge region of the additional substrate support.
8. The apparatus of claim 7, further comprising a load lock chamber disposed between the transfer chamber and the factor interface, wherein the substrate edge processing chamber and the load lock chamber are arranged side by side.
9. The apparatus of claim 1, wherein the gas distribution bowl further comprises an inner wall defining a gas conduit, and the gas conduit opens at a central area of the bottom.
10. The apparatus of claim 9, wherein the gas conduit is adapted to connect with a purge gas source and deliver a purge gas towards a central area of the substrate supporting surface.
11. The apparatus of claim 1, wherein the substrate edge processing chamber is a twin processing chamber coupled to the transfer chamber, the substrate edge processing chamber comprises a chamber body assembly defining a first processing region and a second processing region, the first and second processing regions are arranged side by side, the substrate support and the gas distribution bowl are disposed in the first processing region, and the substrate edge processing chamber further comprises:
- an additional substrate support disposed in the second processing region; and
- an additional gas distribution bowl disposed over the additional substrate support in the second processing region, wherein the additional gas distribution bowl comprises: an outer wall; and a bottom, wherein a plurality of slits are formed near a peripheral region of the bottom, the plurality of slits are configured to deliver a processing gas towards an edge region of the additional substrate support.
12. An apparatus for processing multiple substrates, comprising:
- a loadlock chamber;
- a transfer chamber coupled to the loadlock chamber;
- one or more twin process chambers coupled to the transfer chamber; and
- a substrate edge processing chamber coupled to the transfer chamber, the substrate edge processing chamber comprising: a substrate support having a substrate support surface; a plasma generator configured to supply an etching agent in a plasma phase; and a gas delivery assembly coupled to a gas source, wherein the gas delivery assembly comprises a gas bowl coupled to a chamber lid, the gas bowl comprises: an outer wall; and a bottom facing the substrate support surface, wherein a periphery area of the bottom has a plurality of slits configured to deliver the etching agent from the plasma generator to a peripheral region of the substrate support surface.
13. The apparatus of claim 12, wherein the gas bowl further comprises an inner wall, a gas conduit is defined by the inner wall and opens at a central area of the bottom, and the gas conduit is coupled to a purge gas and delivers a purge gas towards a central region of the substrate support surface.
14. The apparatus of claim 12, wherein the plurality of slits are angled outwards to avoid gas flow towards the center region of the substrate support surface.
15. The apparatus of claim 14, wherein the substrate edge processing chamber comprises a first processing region and a second processing region vertically stacked together.
16. The apparatus of claim 15, wherein the substrate edge processing chamber is disposed between a factory interface and the transfer chamber, and the substrate support and the gas delivery assembly are disposed in the first processing region, and the second processing region is a load lock chamber.
17. The apparatus of claim 15, wherein the substrate support and the gas delivery assembly are disposed in the first processing region, and the substrate edge processing chamber further comprises an additional substrate support and an additional gas delivery assembly disposed in the second processing region.
18. An apparatus for processing a substrate, comprising:
- a chamber body assembly defining a first processing region and a second processing region, the first and second processing regions are vertically stacked together;
- a substrate support having a substrate support surface disposed in the first processing region; and
- a gas distribution bowl disposed over the substrate support in the first processing region, wherein the gas distribution bowl comprises: an outer wall; and a bottom, wherein a plurality of slits are formed near a peripheral region of the bottom, the plurality of slits are configured to deliver a processing gas towards an edge region of the substrate support surface.
19. The apparatus of claim 18, wherein the second processing region is a load lock chamber.
20. The apparatus of claim 18, further comprising:
- an additional substrate support disposed in the second processing region; and
- an additional gas distribution bowl disposed over the additional substrate support in the second processing region, wherein the additional gas distribution bowl comprises: an outer wall; and a bottom, wherein a plurality of slits are formed near a peripheral region of the bottom, the plurality of slits are configured to deliver a processing gas towards an edge region of the additional substrate support.
Type: Application
Filed: Apr 25, 2012
Publication Date: Aug 23, 2012
Applicant: Applied Materials, Inc. (Santa Clara, CA)
Inventors: Ashish Shah (Santa Clara, CA), Dale R. DuBois (Los Gatos, CA), Ganesh Balasubramanian (Sunnyvale, CA), Mark A. Fodor (Los Gatos, CA), Eui Kyoon Kim (Campbell, CA), Chiu Chan (Foster City, CA), Karthik Janakiraman (San Jose, CA), Thomas Nowak (Cupertino, CA), Joseph C. Werner (Santa Clara, CA), Visweswaren Sivaramakrishnan (Cupertino, CA), Mohamad Ayoub (Los Gatos, CA), Amir Al-Bayati (San Jose, CA), Jianhua Zhou (San Jose, CA)
Application Number: 13/456,080
International Classification: H01L 21/3065 (20060101); C23C 16/458 (20060101); C23C 16/50 (20060101); H01L 21/306 (20060101);