The present disclosure relates to alignment of shadow rings in substrate processing systems.
The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
During manufacturing of substrates such as semiconductor wafers, etch processes and deposition processes may be performed within a processing chamber. The substrate is disposed in the processing chamber on a substrate support such as an electrostatic chuck (ESC) or a pedestal. Process gases are introduced and, in some examples, plasma is struck in the processing chamber.
Some substrate supports may include a shadow ring. During deposition and etching processes, a substrate is arranged on the substrate support. The shadow ring may be used to protect outer edges of the substrate from deposition and etching. For example, the shadow ring may be raised to facilitate transfer of the substrate to the substrate support and then lowered. An inner diameter of the shadow ring overlaps the outer edge of the substrate.
A system to align a shadow ring on a substrate support includes a baseplate of the substrate support, an alignment recess defined within an upper surface of the baseplate, a shadow ring, an upper alignment groove defined in a lower surface of the shadow ring, an alignment block disposed within the alignment recess, and an alignment feature disposed between the shadow ring and the alignment block. The alignment feature extends into the upper alignment groove defined in the lower surface of the shadow ring.
In other features, the alignment recess and the alignment block have an interlocking arrangement. The alignment recess and the alignment block have complementary shapes. Each of the alignment recess and the alignment block is “T”-shaped. The alignment recess receives the alignment block from a radially outward direction relative to the substrate support. The alignment block includes a vertical channel and a pin is disposed within the vertical channel. The pin extends from the baseplate below the alignment block into the upper alignment groove. The pin is located radially inward of the alignment feature. The pin is located radially outward of the alignment feature.
In other features, the upper alignment groove is generally rectangular. The lower alignment groove is semicircular. The alignment feature includes a wheel. The alignment block includes a slot that is perpendicular to the lower alignment groove and receives a lower portion of the wheel. A lower alignment groove is defined in an upper surface of the alignment block, the alignment feature includes a shaft coupled to the wheel, and the shaft is aligned with the lower alignment groove.
In other features, the system further includes a controller to lower the shadow ring onto the alignment feature. The system further includes a plurality of the alignment recesses, the alignment blocks, and the alignment features. The system further includes three of the alignment recesses.
A system to align a shadow ring on a substrate support includes a baseplate of the substrate support, an alignment recess defined within an upper surface of the baseplate, a shadow ring, an upper alignment groove defined in a lower surface of the shadow ring, an alignment block disposed within and having an interlocking arrangement with the alignment recess, a lower alignment groove defined in an upper surface of the alignment block, a pin extending from the baseplate and through the alignment block, and an alignment feature disposed between the shadow ring and the alignment block. The alignment features extends into the upper alignment groove defined in the lower surface of the shadow ring and into the lower alignment groove.
In other features, the alignment recess and the alignment block have complementary shapes. Each of the alignment recess and the alignment block is “T”-shaped. The alignment recess receives the alignment block from a radially outward direction relative to the substrate support. The alignment block includes a vertical channel and the pin is disposed within the vertical channel. The alignment feature includes a wheel. The alignment block includes a slot that is perpendicular to the lower alignment groove and receives a lower portion of the wheel.
Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
In the drawings, reference numbers may be reused to identify similar and/or identical elements.
A substrate support may include a shadow ring to protect outer edges of a substrate from deposition and etching during processing. In examples where the shadow ring is used to prevent deposition (e.g., tungsten deposition) on the outer edges of the substrate, a purge gas may be supplied between the shadow ring and the substrate to reduce species concentration at the edge of the substrate and further reduce deposition.
The shadow ring may be configured to be raised and lowered, and may transferred to and from the substrate support. Accordingly, various techniques may be used to align (e.g., center) the shadow ring relative to the substrate support. For example, the shadow ring may be aligned with the substrate support using mechanical components such as screws (e.g., ceramic or metal screws), nuts, springs, wheels, etc. These mechanical components susceptible to failures caused by corrosion, fractures, high temperatures (e.g., damage associated with the presence of fluorine at temperatures above 400° C.), etc.
Shadow ring alignment systems and methods according to the present disclosure implement various features to facilitate alignment while reducing or eliminating mechanical components as described below in more detail.
Referring now to
A gas delivery system 120 includes gas sources 122-1, 122-2, . . . , and 122-N (collectively gas sources 122) that are connected to valves 124-1, 124-2, . . . , and 124-N (collectively valves 124) and mass flow controllers 126-1, 126-2, . . . , and 126-N (collectively MFCs 126). The MFCs 126 control flow of gases from the gas sources 122 to a manifold 128 where the gases mix. An output of the manifold 128 is supplied via an optional pressure regulator 132 to a manifold 136. An output of the manifold 136 is input to a gas distribution device such as a multi-injector showerhead 140. While the manifold 128 and 136 are shown, a single manifold can be used.
In some examples, a temperature of the substrate support 104 may be controlled using resistive heaters 144. The substrate support 104 may include coolant channels 146. Cooling fluid is supplied to the coolant channels 146 from a fluid storage 148 and a pump 150. Pressure sensors 152, 154 may be arranged in the manifold 128 or the manifold 136, respectively, to measure pressure. A valve 156 and a pump 158 may be used to evacuate reactants from the processing chamber 108 and/or to control pressure within the processing chamber 108.
A controller 160 includes a dose controller 162 that controls dosing provided by the multi-injector showerhead 140. The controller 160 also controls gas delivery from the gas delivery system 120. The controller 160 controls pressure in the processing chamber and/or evacuation of reactants using the valve 156 and the pump 158. The controller 160 controls the temperature of the substrate support 104 and the substrate 112 based upon temperature feedback (e.g., from sensors (not shown) in the substrate support and/or sensors (not shown) measuring coolant temperature).
Although described as being configured to perform deposition processes, the substrate processing system 100 may be configured to perform etching processes. In some examples, the substrate processing system 100 may be configured to perform etching on the substrate 112 within the same processing chamber 108 as deposition processes. Accordingly, the substrate processing system 100 may include an RF generating system 164 configured to generate and provide RF power (e.g., as a voltage source, current source, etc.) to one of a lower electrode (e.g., a baseplate of the substrate support 104, as shown) and an upper electrode (e.g., the showerhead 140). The other one of the lower electrode and the upper electrode may be DC grounded, AC grounded or floating.
For example only, the RF generating system 164 may include an RF generator 166 configured to generate the RF voltage that is fed by a matching and distribution network 168 to generate plasma within the processing chamber 108 to etch the substrate 112. In other examples, the plasma may be generated inductively or remotely. Although, as shown for example purposes, the RF generating system 164 corresponds to a capacitively coupled plasma (CCP) system, the principles of the present disclosure may also be implemented in other suitable systems, such as, for example only transformer coupled plasma (TCP) systems, CCP cathode systems, remote microwave plasma generation and delivery systems, etc.
Referring now to
Actuators 180 (e.g., linear actuators responsive to the controller 160) raise and lower the lift pins 178 to raise and lower the shadow ring 170. As shown in
In some embodiments, the shadow ring 170 includes arms or tabs 184 extending radially outward from the shadow ring 170 as shown in a plan view in
The substrate support 104 and shadow ring 170 according to the present disclosure implement alignment features as described below in more detail.
Referring now to
An alignment block 220 is disposed within the alignment recess 212. For example, the alignment block 220 has a shape that is complementary to the shape of the alignment recess 212. As shown, the alignment block 220 is “T”-shaped. Accordingly, the alignment recess 212 and the alignment block 220 have an interlocking arrangement relative to one another. The alignment block 220 may be insertably received within the alignment recess 212 from a radially outward direction. Conversely, the interlocking arrangement of the alignment block 220 within the alignment recess 212 prevents lateral and upward movement of the alignment block 220 relative to the baseplate 204. For example only, the alignment block 220 is comprised of a dielectric material (e.g., alumina or another ceramic).
The alignment block 220 includes a vertical via or channel 224. A pin 228 is arranged in the channel 224. For example, the pin 228 extends upward from a corresponding channel 232 in the baseplate 204, through the alignment block 220, and into an upper alignment groove (e.g., a generally rectangular groove) 236 defined in a lower surface 240 of the shadow ring 208. The upper alignment groove 236 extends in a radial direction relative to the baseplate 204. The pin 228 fixes a position of the alignment block 220 relative to the alignment recess 212 and the baseplate 204. For example, the pin 228 prevents movement of the alignment block 220 in lateral and radial directions. The pin 228 is comprised of a dielectric material such as ceramic.
A lower alignment groove (e.g., a semicircular groove) 244 is defined in an upper surface 248 of the alignment block 220. The lower alignment groove 244 extends in a radial direction relative to the baseplate 204. The lower alignment groove 244 is aligned with the upper alignment groove 236 (e.g., in a radial direction). The lower alignment groove 244 and the upper alignment groove 236 are configured to receive and retain an alignment feature arranged between the alignment block 220 and the shadow ring 208, such as an alignment disc or wheel 250. The wheel 250 is coupled to an axle or shaft 252. The wheel 250 and the shaft 252 are comprised of a dielectric material such as ceramic. In other examples, the alignment feature extends upward from the alignment block 220.
In some examples, the wheel 250 is configured to rotate within the alignment block 220 on an axis defined by the shaft 252. For example, as shown in
As shown in more detail in
The pin 228 and the wheel 250 are configured to align (e.g., center) the shadow ring 208 on the baseplate 204. For example, a substrate is arranged on the baseplate 204 (e.g., with the shadow ring 208 in a raised position as shown in
Conversely, the orientation of the upper alignment grooves 236 allows movement of the pins 228 in the radial direction. In other words, the pins 228 are allowed to move within the upper alignment grooves in a radial inward direction and a radial outward direction relative to the shadow ring. For example, the baseplate 204 may be comprised of a metal such as aluminum that expands and contracts with changes in temperature. The pins 228 move radially outward and inward as the baseplate 204 expands and contracts, respectively. Accordingly, expansion and contraction of the baseplate 204 do not cause misalignment of the shadow ring 208, damage to the shadow ring 208, etc.
Another example shadow ring alignment assembly 300 (e.g., of a substrate support) according to the present disclosure is shown in
The alignment block 320 includes an alignment feature 350. In this example, the alignment feature 350 extends upward from the alignment block 320 into the upper alignment groove 336. The alignment feature 350 may be integrally formed with the alignment block 320. The alignment feature 350 may be conical, rounded, etc. to facilitate alignment of the shadow ring 308 on the baseplate 304.
A lower alignment groove (e.g., a semicircular groove) 244 is defined in an upper surface 248 of the alignment block 220. The lower alignment groove 244 extends in a radial direction relative to the baseplate 204. The lower alignment groove 244 is aligned with the upper alignment groove 236 (e.g., in a radial direction). The lower alignment groove 244 and the upper alignment groove 236 are configured to receive and retain an alignment mechanism, such as an alignment disc or wheel 250. The wheel 250 is coupled to an axle or shaft 252. The wheel 250 and the shaft 252 are comprised of a dielectric material such as ceramic.
Shadow ring alignment systems and methods according to the present disclosure may further implement lift pins configured to align the substrate and shadow ring as described below in more detail.
Referring now to
An outer edge of the substrate 408 is supported on a sleeve 420 disposed around a flange 422 on an upper end of the lift pin 404. The flange 422 may be comprised of ceramic. For example, the sleeve 420 may include a minimum contact area feature (such as a bump 424) configured to support the substrate 408. As shown in
The shadow ring 412 can then be lowered onto the lift pins 404. For example, the shadow ring 412 includes centering features such as tapered slots or ramps 432 on a lower surface 436 of the shadow ring 412. Although shown as indentations or notches in the lower surface 436 of the shadow ring 412, in other examples the ramps 432 may be configured as protrusions or projections extending downward from the lower surface 436. As the shadow ring 412 is lowered onto the wheels 416, the ramps 432 receive respective ones of the wheels 416. Contact between the ramps 432 and the wheels 416 biases the shadow ring 412 into a centered position relative to the substrate support 400. With the substrate 408 supported on the sleeve 420 and the shadow ring 412 supported on the wheels 416, the lift pins 404 are lowered to lower the substrate 408 and the shadow ring 412 onto the substrate support 400. In this manner, the lift pins 404 and the wheels 416 are configured to center both the substrate 408 and the shadow ring 412 relative to each other and the substrate support 400.
An example process for centering the substrate 408 and the shadow ring 412 on the substrate support 400 according to the present disclosure is shown in
Referring not to
As shown in
As shown in
The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure.
Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”
In some implementations, a controller is part of a system, which may be part of the above-described examples. Such systems can comprise semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, and/or specific processing components (a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate. The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems. The controller, depending on the processing requirements and/or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and/or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a tool and other transfer tools and/or load locks connected to or interfaced with a specific system.
Broadly speaking, the controller may be defined as electronics having various integrated circuits, logic, memory, and/or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and/or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some embodiments, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and/or dies of a wafer.
The controller, in some implementations, may be a part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process. In some examples, a remote computer (e.g. a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and/or settings, which are then communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control. Thus as described above, the controller may be distributed, such as by comprising one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.
Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing systems that may be associated or used in the fabrication and/or manufacturing of semiconductor wafers.
As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and/or load ports in a semiconductor manufacturing factory.
This application claims the benefit of U.S. Provisional Application No. 63/176,683, filed on Apr. 19, 2021. The entire disclosures of the applications referenced above are incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/US2022/025002 | 4/15/2022 | WO |
Number | Date | Country | |
---|---|---|---|
63176683 | Apr 2021 | US |