Honeycomb ejector with dielectric window for substrate processing system

Abstract

An assembly for a substrate processing chamber includes: a quartz dielectric window configured to be disposed in an upper surface of the substrate processing chamber; a recess in the quartz dielectric window, the recess including a first opening extending through the quartz dielectric window; and a gas injector assembly including the gas injector. The gas injector assembly is disposed within the recess such that the gas injector extends through the first opening. The gas injector consists of solid yttrium oxide and / or comprises an outer surface with a yttrium oxide coating.

Description

This application is a divisional application of the invention patent application with the application date of July 29, 2019, Chinese patent application number 201980050687.0, and the invention name of “Honeycomb injector with dielectric window for substrate processing system”. Cross Reference to Related Applications

[0001] This application claims the benefit of U.S. Provisional Application No. 62 / 712,415, filed July 31, 2018. The entire disclosure of the above-referenced application is incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure relates to a gas injector for a substrate processing system. BACKGROUND

[0003] The background description provided here is for the purpose of generally presenting the context of the disclosure. Aspects of the work of the inventors mentioned in this background section can not be prior art to the present disclosure and are not admitted to be prior art by virtue of their inclusion in this background section.

[0004] During the manufacturing of a substrate, such as a semiconductor wafer, etching processes and deposition processes can be performed within a processing chamber. The substrate is disposed on a substrate support, such as an electrostatic chuck (ESC) or susceptor, in the processing chamber. A process gas is introduced and a plasma is ignited in the processing chamber.

[0005] The processing chamber can include a transformer coupled plasma (TCP) reactor coil. A radio frequency (RF) signal generated by a power source is provided to the TCP reactor coil. A dielectric window is incorporated into an upper surface of the processing chamber. The dielectric window maintains a vacuum seal of the processing chamber while allowing the RF signal to be transmitted from the TCP reactor coil to an interior of the processing chamber. The RF signal excites gas molecules within the processing chamber to generate a plasma. SUMMARY

[0006] An assembly for a substrate processing chamber includes a quartz dielectric window configured to be disposed in an upper surface of the substrate processing chamber, a recess in the quartz dielectric window including a first opening extending through the quartz dielectric window, and a gas injector assembly including a gas injector. The gas injector assembly is disposed within the recess such that the gas injector extends through the first opening. The gas injector is composed of and / or includes an outer surface having a coating of yttrium oxide.

[0007] In other features, the gas injector corresponds to a gas injector of a honeycomb configuration including a plurality of gas outlets. The assembly further includes a socket disposed in the recess, the socket including a second opening and the gas injector extending through the second opening. The second opening corresponds to a bayonet opening. The socket comprises at least one of plastic and quartz. The assembly further includes a nut assembly disposed to secure the gas injector assembly within the second opening. The nut assembly is configured for a twist-to-lock operation. The assembly further includes a radio frequency shield disposed between the nut assembly and the gas injector.

[0008] In other features, the assembly further includes a seal disposed between the radio frequency shield and a gas connection block of the gas injector assembly. The radio frequency shield includes a slot configured to receive a body of the nut assembly. The slot is disposed above the socket. The gas injector includes a flange disposed within the second opening and a lower flange of the radio frequency shield is positioned above the flange of the gas injector and the socket.

[0009] In other features, the assembly further includes a seal disposed in a groove between the gas injector and the dielectric window. The seal is an O-ring. The assembly further includes a socket disposed in the recess including a second opening, the gas injector extending through the second opening, and the gas injector including a flange disposed within the second opening. A height of the flange is substantially equal to at least one of a depth of the first opening and a height of the socket. An upper surface of the flange is flush with an upper surface of the socket.

[0010] An assembly for a substrate processing chamber includes a quartz dielectric window configured to be disposed in an upper surface of the substrate processing chamber, a central recess in the quartz dielectric window including a first opening extending through the quartz dielectric window, a socket disposed in the central recess including a second opening, and a gas injector assembly including a gas injector. The gas injector assembly is disposed within the central recess such that the gas injector extends through the second opening. The gas injector includes a plurality of gas outlets and is composed of and / or includes an outer surface having a coating of yttrium oxide.

[0011] In other features, the assembly further includes a nut assembly disposed to secure the gas injector assembly within the second opening. The gas injector includes a flange disposed within the second opening. A height of the flange is substantially equal to at least one of a depth of the first opening and a height of the socket such that an upper surface of the flange is flush with an upper surface of the socket.

[0012] Other applications of the present disclosure will become apparent from the specific embodiments, claims, and descriptions provided herein. The specific embodiments and particular examples are intended to be illustrative only and not limiting of the scope of the disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0013] The disclosure will become more fully understood from the detailed description and accompanying drawings, wherein:

[0014] Figure 1A is an example of a substrate processing system including a dielectric window according to the present disclosure;

[0015] Figure 1B and 1C shows an example dielectric window according to the present disclosure;

[0016] Figure 1D and 1E shows an example gas injector assembly according to the present disclosure; and

[0017] Figure 2A , 2B , 2C, and 2D show gas injectors according to the present disclosure.

[0018] In the drawings, reference numerals can be repeated among the figures for like and / or identical elements. DETAILED DESCRIPTION

[0019] A substrate processing system can include a dielectric window incorporated into an upper surface of a processing chamber. A gas injector assembly is disposed in an opening of the dielectric window to inject process gas into the processing chamber. In some examples, the dielectric window includes a central recess and a socket disposed in the recess. The socket includes a bayonet opening configured to receive the gas injector assembly.

[0020] The dielectric window can be composed of a material such as ceramic or quartz and can or can not be coated with another material. The gas injector assembly includes a gas injector that can include one or more materials, such as ceramic, quartz, yttria, etc., and can or can not be coated with another material. Different gas injector assemblies can be configured to engage with different types of dielectric windows and / or dielectric windows having different recess designs, different sizes, etc. For example, quartz dielectric windows can be more fragile (e.g., relative to ceramic) and thus susceptible to cracking from insertion of a gas injector assembly. As such, the configuration of the recess, bayonet, and / or other features can need to be adjusted and the gas injector can need to be modified to accommodate the adjusted configuration. In other examples, the effectiveness of a seal between the gas injector assembly and the dielectric window can depend on the materials and configuration of the gas injector assembly and the dielectric window. An example dielectric window and gas injector assembly having a honeycomb configuration are described in greater detail in U.S. Patent 9,947,512, which is incorporated by reference herein in its entirety. As described therein, a gas injector having a honeycomb configuration reduces center defects associated with substrate processing and improves yield. As used herein, the term “honeycomb” means that the gas injector has a plurality of gas outlets as described in greater detail below.

[0021] In some examples, a quartz dielectric window can be configured to interface with a gas injector assembly containing a gas injector comprising quartz, ceramic, aluminum, stainless steel, alumina, silicon nitride, etc. Conversely, a ceramic dielectric window can be configured to interface with a gas injector assembly containing a yttria gas injector. However, conventional designs do not contain a quartz dielectric window configured to interface with a gas injector assembly containing a solid state yttria gas injector or a non-yttria gas injector with a yttria coating. For example, due to the brittle nature of high purity quartz and yttria, it is difficult to prevent chipping of the quartz dielectric window and the yttria gas injector while maintaining a sufficient seal between the gas injector assembly and the dielectric window during installation. For example, existing quartz dielectric windows use a clip to secure the quartz gas injector, which will not provide a sufficient seal for solid state yttria and / or yttria coated gas injectors.

[0022] A quartz dielectric window and gas injector assembly according to the present disclosure are configured to be used with a gas injector assembly containing a gas injector composed of solid state yttria or a non-yttria material with a yttria coating. The dielectric window contains a central recess and a socket configured to receive an adapter (e.g., a bayonet adapter) and a nut assembly for securing the gas injector assembly. The adapter facilitates and ensures that an O-ring seal is compressed between the gas injector and the dielectric window without damaging the gas injector or the dielectric window. Furthermore, yttria is less prone to flaking and has other particle generation defects than other gas injector materials, which results in fewer defects in the processed substrates.

[0023] Referring now to Figure 1A , an example of a substrate processing system 10 according to the present disclosure is shown. The substrate processing system 10 contains a coil drive circuit 11. In some examples, the coil drive circuit 11 includes an RF source 12 and a tuning circuit 13. The tuning circuit 13 can be connected directly to one or more inductive TCP coils 16. Alternatively, the tuning circuit 13 can be connected to one or more coils 16 through optional reversible circuitry 15. The tuning circuit 13 tunes the output of the RF source 12 to a desired frequency and / or a desired phase, matches the impedance of the coils 16, and distributes power among the TCP coils 16. The reversible circuitry 15 is used to selectively switch the polarity of the current through one or more TCP coils 16.

[0024] A plenum 20 can be disposed between the TCP coil 16 and the dielectric window 24 to utilize a flow of hot and / or cold air to control the temperature of the dielectric window 24. The dielectric window 24 is disposed along a side of a process chamber 28. The process chamber 28 also includes a substrate support (or pedestal) 32. The substrate support 32 can include an electrostatic chuck (ESC), or a mechanical chuck, or other type of chuck. Process gas is supplied to the process chamber 28 and a plasma 40 is generated inside the process chamber 28. The plasma 40 etches an exposed surface of a substrate 34. The RF source 50 and bias matching circuit 52 can be used to bias the substrate support 32 during operation to control ion energy.

[0025] A gas delivery system 56 can be used to supply a process gas mixture to the process chamber 28. The gas delivery system 56 can include process and inert gas sources 57; a gas metering system 58, such as valves and mass flow controllers; and a manifold 59. A gas delivery system 60 can be used to deliver a gas 62 to the plenum 20 via a valve 61. The gas can include a cooling gas (air) for cooling the TCP coil 16 and the dielectric window 24. A heater / cooler 64 can be used to heat / cool the substrate support 32 to a predetermined temperature. An exhaust system 65 includes a valve 66 and a pump 67 to remove reactants from the process chamber 28 by purging or evacuating.

[0026] A controller 54 can be used to control the etching process. The controller 54 monitors system parameters and controls the delivery of gas mixtures, the striking, sustaining, and extinguishing of the plasma, the removal of reactants, the supply of cooling gas, etc. In addition, as described in detail below, the controller 54 can control various aspects of the coil drive circuit 11, the RF source 50 and bias matching circuit 52, etc. For example, a process chamber using a TCCT matching network with switched capacitors is shown and described in commonly-assigned U.S. Patent No. 9,515,633, which is incorporated by reference herein in its entirety.

[0027] A temperature controller 68 can be connected to a plurality of heating elements 70, such as thermal control elements (TCEs), disposed in the substrate support 32. The heating elements 70 can include, but are not limited to, macro heating elements, which correspond to individual zones in a multi-zone heating plate; and / or an array of micro heating elements, which are disposed on multiple zones of a multi-zone heating plate. The temperature controller 68 can be used to control the plurality of heating elements 70 to control the temperature of the substrate support 32 and the substrate 34, as described in greater detail below.

[0028] The dielectric window 24 according to the present disclosure is a quartz dielectric window configured to house solid yttria and / or yttria-coated gas jets (not shown in the Figures), as described in greater detail below. Figure 1A ​

[0029] Referring now to Figure 1B , 1C , 1D and 1E, exemplary dielectric window 100 and gas injector assembly 104 containing gas injector 108 composed of yttria are shown in greater detail in accordance with the principles of the present disclosure. For example, gas injector 108 can be composed of solid yttria, or can include a non-yttria material having a yttria coating. In other words, the outer surface of gas injector 108 can contain a coating of yttria. Dielectric window 100 is composed of quartz (e.g., high purity quartz). Dielectric window 100 contains a central recess 112 configured to house gas injector 108. Central recess 112 contains an opening 116 extending through dielectric window 100. Figure 1B and Figure 1C show a view of dielectric window 100, while Figure 1D and Figure 1E show an assembly containing dielectric window 100 and gas injector assembly 104 mounted within dielectric window 100.

[0030] Gas injector assembly 104 is arranged within central recess 112 such that gas injector 108 extends through opening 116 of dielectric window 100. For example, a socket 120 (e.g., an annular socket, such as a disc socket) is arranged in central recess 112. Socket 120, which can be composed of plastic, quartz, or another dielectric material, contains an opening 124 (e.g., a bayonet opening) configured to house gas injector assembly 104.

[0031] Gas injector 108 (e.g., a honeycomb configuration gas injector containing a plurality of gas outlets 128) extends through opening 124 and opening 116 and into processing chamber 28. A nut assembly 132 secures gas injector assembly 104 within opening 124. For example, nut assembly 132 is configured for a twist-to-lock operation, such as described in U.S. Patent 9,947,512. An RF shield 136 is arranged between nut assembly 132 and gas injector 108. For example, RF shield 136 contains a metal, such as copper, aluminum, or the like, and / or can be coated with a metal (e.g., silver).

[0032] Gas injector assembly 104 contains one or more O-rings to provide a gas seal between various components of gas injector assembly 104. For example, an O-ring 140 is arranged between gas injector 108 (e.g., in a groove) and dielectric window 100. An O-ring 144 is arranged between RF shield 136 and a gas connection block 148. An O-ring 152 is arranged between gas injector 108 and gas connection block 148.

[0033] The gas injector 108 includes a flange (e.g., an annular flange) 156 configured to secure the gas injector 108 within the socket 120 of the dielectric window 100. Because yttria is brittle and more prone to damage, the height / depth of the flange 156 is greater than gas injectors that include materials other than yttria, where the flange 156 includes a groove for the O-ring 140 and can break under pressure. For example, the vertical height of the flange 156 can be substantially equal to the depth of the opening 112 and the height of the socket 120 (e.g., within 0.05 inches or 1.25 mm). By way of example only, the height of the flange 156 is 0.5 inches (+ / - 0.05 inches) or 12.7 mm. Accordingly, the upper surface of the flange 156 is flush with the upper surface of the socket 120.

[0034] The RF shield 136 includes a slot 160 configured to accommodate the main body 164 of the nut assembly 132. For example, the slot 160 is disposed above (i.e., not within) the socket 120. Further, a lower flange 168 of the RF shield 136 is above the flange 156 and the socket 120.

[0035] Figure 2A 2B FIGS. 2C and 2D illustrate alternative views of an exemplary gas injector 200 composed of yttria (e.g., solid yttria or another material having a coating of yttria) according to the principles of the present disclosure. For example, Figure 2A FIG. 2A illustrates an isometric view of the gas injector 200. Figure 2B FIG. 2B illustrates a cross-sectional view of the gas injector 200. Figure 2C FIG. 2D illustrates a side view of the gas injector 200. Figure 2D FIG. 2E illustrates an enlarged view of the feature 204 shown in FIG. 2D. Figure 2B FIG. 2E illustrates an enlarged view of the feature 204 shown in FIG. 2D.

[0036] The above 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 limited to such examples. One or more steps within a method can be performed in different orders (or concurrently) without altering the principles of the embodiments. Further, each of the embodiments described herein can be implemented in a different form without departing from the principles of the disclosure. For example, the methods described herein can be implemented in software or hardware, or a combination thereof. In addition, one or more steps within each of the methods described herein can be performed in a different order (or concurrently) without departing from the principles of the disclosure. Additionally, one or more steps within each of the methods described herein can be performed by one or more different entities without departing from the principles of the disclosure. Additionally, each of the embodiments described herein can be implemented in a different order without departing from the principles of the disclosure. Furthermore, the intervening steps can be performed in a different order without departing from the principles of the disclosure. Additionally, one or more steps described herein can be combined without departing from the principles of the disclosure.​

[0037] Various terminology is used to describe spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) as well as relationships between elements and other features. Such terminology includes the words "connected," "engaged," "coupled," "adjacent," "near," "on," "above," "below," and "disposed." Unless specifically described as "direct," relationships between or among components, as described by the foregoing terminology, can be indirect — in that one or more other components can be interposed between (spatially or functionally) the components in the relationship. 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 the inclusive OR, and should be not be construed to mean A of at least one or B of at least one or C of at least one (A AND B AND C).

[0038] In some implementations, a controller is part of a system that can be part of the above examples. Such systems can include semiconductor processing equipment, including one or more processing tools, one or more chambers, one or more platforms, and / or a particular processing component (wafer pedestal, gas flow system, etc.). These systems can be integrated with electronics for controlling their operation before, during, and after process semiconductor wafers or substrates are processed. The electronics can be referred to as the "controller," which can control various components or subparts of the system or systems. Depending on the process requirements, the controller can be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., of 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 position within the tool and other transfer tools and / or load locks connected to or interfaced with the particular system.

[0039] Broadly speaking, the controller can 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 can 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 can be instructions communicated to the controller in the form of various individual settings (or programs) of the various parameters defined for processing a particular wafer, or for carrying out a particular process on or for a system. In some embodiments, the operational parameters can be part of a process recipe. The process recipe can define the sequence of operations to be performed during processing, along with the parameters to be used by the controller during each of the operations. Each of the operations can be performed under control to enable data collection, cleaning operations, endpoint measurements, and the like.

[0040] In some embodiments, the controller can be part of, or coupled to, a computer that is integrated with, coupled to, otherwise networked to, or a combination thereof, the system. For example, the controller can be in "the cloud" or all or a part of a fab host computer system that enables remote access to the wafer processing. The computer can enable remote access by users to control the system to, for example, 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, set processing steps to follow for a current process, or to start a new process. In some examples, a remote computer (e.g., a server) can provide processing recipes to a system over a network, which can include an intranet or the internet. The remote computer can include a user interface that enables entry or programming of parameters and / or settings that are then communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data that specifies parameters for each of the processing steps to be executed during one or more operations. It should be understood that the parameters can be specific to a type of process to be performed and a type of tool that the controller is configured to interface with or control. Thus, as described above, the controller can be distributed, such as by including one or more discrete controllers that are networked together and working toward 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 off-board (e.g., at the platform level or as part of a remote computer) that combine to control processes on the chamber.

[0041] The example system can include, without limitation, a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a pre- clean or post-clean chamber or module, a bevel edge etch chamber or module, a physical vapor

[0042] As noted above, depending on the process step or steps to be performed by the tool, the controller will 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 the factory, a main computer, another controller, or another tool (that carries a wafer container to and / or from a tool location and / or load port in a semiconductor manufacturing factory) for material transport.

Claims

1. A gas ejector, comprising: An annular flange, wherein the annular flange includes at least one groove at its bottom for receiving a seal; The first set of gas outlets is located at the bottom of the gas injector; and At least one second gas outlet is arranged radially outside the first group of gas outlets. The gas injector includes an outer surface with a yttrium oxide coating, or the outer surface is made of yttrium oxide.

2. The gas injector according to claim 1, wherein the first set of gas outlets is arranged in a honeycomb structure.

3. The gas injector of claim 1, wherein the annular flange is not made of yttrium oxide.

4. The gas injector of claim 1, wherein the annular flange is configured to secure the gas injector to the dielectric window.

5. The gas injector according to claim 1, wherein the outer surface of the gas injector has the yttrium oxide coating.

6. The gas injector according to claim 1, wherein the gas injector is composed of yttrium oxide.

7. The gas injector according to claim 1, wherein the gas injector comprises at least one of ceramic, quartz, aluminum, stainless steel, alumina or silicon nitride.

8. The gas injector of claim 1, wherein the groove is configured to receive an O-ring seal.

9. The gas injector of claim 8, wherein the groove has a rectangular cross-sectional profile.

10. The gas injector of claim 1, wherein the vertical height of the annular flange is in the range of 0.45 inches and 0.55 inches.

11. The gas injector of claim 10, wherein the vertical height of the annular flange is 0.5 inches.

12. The gas injector according to claim 1, wherein, The at least one second gas outlet includes a group of multiple second gas outlets, each of which is arranged radially outside the first group of gas outlets.

13. The gas injector of claim 12, wherein the plurality of second gas outlets are equidistantly spaced around the circumference of the gas injector.

14. The gas injector according to claim 1, wherein, The annular flange is located between the bottom and the top of the gas injector.

15. The gas injector of claim 14, wherein the annular flange is located at the midpoint of the gas injector along its length.

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