TWI838390B - Honeycomb injector with dielectric window for substrate processing systems - Google Patents

Abstract

An assembly for a substrate processing chamber includes a quartz dielectric window configured to be arranged in an upper surface of the substrate processing chamber, a recess in the quartz dielectric window that includes a first opening that extends through the quartz dielectric window, and a gas injector assembly that includes a gas injector. The gas injector assembly is arranged within the recess such that the gas injector extends through the first opening. The gas injector is comprised of solid yttria and/or includes an outer surface having an yttria coating.

Description

Honeycomb injector utilizing dielectric window for substrate processing system

This application claims priority to U.S. Provisional Application No. 62/712,415 filed on July 31, 2018, the entire disclosure of which is incorporated herein by reference.

The present disclosure relates to a gas injector for a substrate processing system.

The prior art section provided here is for the purpose of generally presenting the contents of the disclosure. The work results of the inventors listed in this case, the scope described in this prior art section, and the description of the implementation mode of the prior art at the time of application are not qualified, and are not explicitly or implicitly admitted as prior art against the contents of the disclosure.

During the manufacture of substrates such as semiconductor wafers, etching processes and deposition processes may be performed in a processing chamber. A 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 plasma is ignited in the processing chamber.

The processing chamber may include a transformer coupled plasma (TCP) reactor coil. A radio frequency (RF) signal generated by a power source is supplied to the TCP reactor coil. A dielectric window is incorporated into the 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 into the interior of the processing chamber. The RF signal excites gas molecules within the processing chamber to generate plasma.

A component for a substrate processing chamber comprises: a quartz dielectric window configured to be disposed in an upper surface of the substrate processing chamber; a recessed portion in the quartz dielectric window, the recessed portion comprising a first opening, the first opening extending through the quartz dielectric window; and a gas injector assembly comprising a gas injector. The gas injector assembly is disposed in the recessed portion such that the gas injector extends through the first opening. The gas injector is composed of solid yttrioxide and/or comprises an outer surface having a yttrioxide coating.

In other features, the gas injector corresponds to a gas injector of a honeycomb arrangement including a plurality of gas outlets. The assembly further includes an insert disposed in the recess, the insert including a second opening and the gas injector extending through the second opening. The second opening corresponds to a latch opening. The insert is formed of at least one of plastic and quartz. The assembly further includes a nut assembly configured to secure the gas injector assembly within the second opening. The nut assembly is configured for a twist-lock operation. The assembly further includes an RF shield disposed between the nut assembly and the gas injector.

In other features, the assembly further includes a seal disposed between the RF shield and a gas connection block of the gas injector assembly. The RF shield includes a groove configured to receive a body of the nut assembly. The groove is disposed above the insert. The gas injector includes a flange disposed within the second opening, and a lower flange of the RF shield is located above the flange of the gas injector and the insert.

In other features, the assembly further includes a seal disposed in a recess between the gas injector and the dielectric window. The seal is an O-ring. The assembly further includes an insert disposed in the recess, the insert including a second opening through which the gas injector extends; and the gas injector includes a flange disposed in the second opening. A height of the flange is substantially the same as at least one of a depth of the first opening and a height of the insert.

A component for a substrate processing chamber, comprising: a quartz dielectric window, arranged to be disposed in an upper surface of the substrate processing chamber; a central recess, in the quartz dielectric window, the central recess comprising a first opening, the first opening extending through the quartz dielectric window; an insert, disposed in the central recess, the insert comprising a second opening; and a gas injector assembly, comprising a gas injector. The gas injector assembly is disposed in the central recess so that the gas injector extends through the second opening. The gas injector comprises a plurality of gas outlets and is composed of solid yttrioxide and/or comprises an outer surface having a yttrioxide coating.

In other features, the assembly further includes a nut assembly configured to secure the gas injector assembly in the second opening. The gas injector includes a flange configured in the second opening. A height of the flange is substantially the same as at least one of a depth of the first opening and a height of the insert, such that an upper surface of the flange is flush with an upper surface of the insert.

Further areas of application of the present disclosure will become apparent from the detailed description, the scope of the claimed patent, and the drawings. The detailed description and specific examples are intended for illustrative purposes only and are not intended to limit the scope of the present disclosure.

10: Substrate processing system

11: Coil drive circuit

12:RF source

13: Tuning circuit

15: Reverse circuit

16: Coil

20: Inflatable part

24: Dielectric window

28: Processing chamber

32: Substrate support

34: Substrate

40: Plasma

50:RF source

52: Bias matching circuit

54: Controller

56: Gas delivery system

57: Process and inert gas source

58: Gas metering system

59: Manifold

60: Gas delivery system

61: Valve

62: Gas

64: Heater/Cooler

65: Exhaust system

66: Valve

67: Pump

68: Temperature controller

70: Heating components

100: Dielectric window

104: Gas injector assembly

108: Gas injector

112: Central depression

116: Open mouth

120:Inlay

124: Open mouth

128: Gas outlet

132: Nut assembly

136:RF shielding

140: O-ring

144:O-ring

148: Gas connection block

152: O-ring

156: flange

160: Slot

164: Subject

168: Lower flange

200: Gas syringe

204: Features Department

The disclosure herein will be more fully understood from the detailed description and the accompanying drawings, wherein: FIG. 1A is an example of a substrate processing system including a dielectric window according to the present disclosure; FIGS. 1B and 1C show examples of dielectric windows according to the present disclosure; FIGS. 1D and 1E show examples of gas injector assemblies according to the present disclosure; and FIGS. 2A, 2B, 2C, and 2D show gas injectors according to the present disclosure.

In the drawings, reference numbers may be repeated to identify similar and/or identical parts.

A substrate processing system may include a dielectric window incorporated into an upper surface of a processing chamber. A gas injector assembly is disposed at an opening of the dielectric window to inject a process gas into the processing chamber. In some examples, the dielectric window includes a central recess and an insert disposed in the recess. The insert includes a latch opening configured to receive the gas injector assembly.

The dielectric window may be constructed of materials such as ceramic or quartz, and may or may not be coated with another material. The gas injector assembly includes a gas injector, which may include one or more materials such as ceramic, quartz, yttrium trioxide, etc., and may or may not be coated with another material. Different gas injector assemblies may be configured to interface with different types of dielectric windows and/or windows having different recess designs, different sizes, etc. For example, a quartz dielectric window may be more fragile (e.g., relative to ceramic) and therefore susceptible to shattering due to insertion of a gas injector assembly. Therefore, the configuration of the recess, latch, and/or other features may need to be adjusted and the gas injector may need to be modified to accommodate the adjusted configuration. In other examples, the effectiveness of the seal between the gas injector assembly and the dielectric window may 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 arrangement is described in further detail in U.S. Patent No. 9,947,512, the entire contents of which are incorporated herein by reference. As described therein, a gas injector having a honeycomb arrangement reduces center defects associated with substrate processing and improves yield. As used herein, the term "honeycomb" means a gas injector having a plurality of gas outlets as described in more detail below.

In some examples, a quartz dielectric window may be configured to interface with a gas injector assembly, including a gas injector comprising quartz, ceramic, aluminum, stainless steel, alumina, silicon nitride, etc. Conversely, a ceramic dielectric window may be configured to interface with a gas injector assembly, including a yttrioxide gas injector. However, conventional designs do not include a quartz dielectric window configured to interface with a gas injector assembly, including a solid yttrioxide gas injector or a non-yttrioxide gas injector having a yttrioxide coating. For example, because high purity quartz and yttrium trioxide are relatively brittle, it is difficult to prevent the quartz dielectric window and yttrium trioxide gas injector from breaking during installation while maintaining an adequate seal between the gas injector assembly and the dielectric window. For example, existing quartz dielectric windows use clips to secure the quartz gas injector, which will not provide an adequate seal with solid yttrium trioxide and/or yttrium trioxide-coated gas injectors.

The quartz dielectric window and gas injector assembly according to the present disclosure is configured for use with a gas injector assembly comprising a gas injector composed of solid yttrioxide or a non-yttrioxide material accompanied by a yttrioxide coating. The dielectric window includes a central recessed portion, and an insert configured to accommodate a connector (such as a latch connector), and a nut assembly for securing the gas injector assembly. The connector facilitates and ensures compression of the O-ring seal between the gas injector and the dielectric window without damaging the gas injector or the dielectric window. Furthermore, yttrioxide is less susceptible to flaking and other particle-generating defects than other gas injector materials, which results in fewer defects in the processed substrate.

Referring now to FIG. 1A , an example of a substrate processing system 10 according to the present disclosure is shown. The substrate processing system 10 includes 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 may be directly connected to one or more inductive TCP coils 16. Alternatively, the tuning circuit 13 may be connected to the one or more coils 16 via an optional reverse circuit 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 reverse circuit 15 is used to selectively switch the polarity of the current passing through the one or more TCP coils 16.

The plenum 20 may be disposed between the TCP coil 16 and the dielectric window 24 to control the temperature of the dielectric window 24 using heat and/or cold airflow. The dielectric window 24 is disposed along a side of the processing chamber 28. The processing chamber 28 further includes a substrate support (or base) 32. The substrate support 32 may include an electrostatic chuck (ESC), or a mechanical chuck or other type of chuck. A process gas is supplied to the processing chamber 28 and a plasma 40 is generated inside the processing chamber 28. The plasma 40 etches the exposed surface of the substrate 34. An RF source 50 and a bias matching circuit 52 may be used to bias the substrate support 32 during operation to control ion energy.

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

The controller 54 can be used to control the etching process. The controller 54 monitors system parameters and controls: the delivery of the gas mixture; the ignition, maintenance 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 embodiments of the coil drive circuit 11, the RF source 50, and the bias matching circuit 52, etc. For example, a processing chamber using a TCCT matching network with a switched capacitor is shown and described in commonly assigned U.S. Patent No. 9,515,633, the entire contents of which are incorporated herein by reference.

The temperature controller 68 may be connected to a plurality of heating elements 70, such as a thermal control element (TCE), disposed in the substrate support 32. The heating elements 70 may include, but are not limited to, macro heating elements corresponding to opposing zones of the multi-zone heating plate and/or arrays of micro heating elements disposed across multiple zones of the multi-zone heating plate. As described in more detail below, the temperature controller 68 may 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 more detail below, the dielectric window 24 according to the present disclosure is a quartz dielectric window configured to receive solid yttrium and/or a gas injector coated with yttrium (not shown in FIG. 1A ).

Referring now to FIGS. 1B , 1C, 1D, and 1E , an example dielectric window 100 and a gas injector assembly 104 including a gas injector 108 comprised of yttrioxide are shown in greater detail in accordance with the principles of the present disclosure. For example, the gas injector 108 may be comprised of solid yttrioxide or may include a non-yttrioxide material having a yttrioxide coating. In other words, the outer surface of the gas injector 108 may include a yttrioxide coating. The dielectric window 100 is comprised of quartz (e.g., high purity quartz). The dielectric window 100 includes a central recess 112 configured to receive the gas injector 108. The central recess 112 includes an opening 116 extending through the dielectric window 100. Figures 1B and 1C show diagrams of a dielectric window 100 and Figures 1D and 1E show an assembly including a dielectric window 100 and a gas injector assembly 104 mounted in the dielectric window 100.

The gas injector assembly 104 is disposed in the central recess 112 so that the gas injector 108 extends through the opening 116 of the dielectric window 100. For example, an insert 120 (e.g., an annular insert such as a disc) is disposed in the central recess 112. The insert 120, which may be made of plastic, quartz, or another dielectric material, includes an opening 124 (e.g., a latch opening) configured to receive the gas injector assembly 104.

The gas injector 108 (e.g., a gas injector in a honeycomb arrangement including a plurality of gas outlets 128) extends through the opening 124 and the opening 116 and into the processing chamber 28. The nut assembly 132 secures the gas injector assembly 104 within the opening 124. For example, the nut assembly 132 is configured for a twist-lock operation, such as described in U.S. Patent No. 9,947,512. The RF shield 136 is disposed between the nut assembly 132 and the gas injector 108. For example, the RF shield 136 includes a metal such as copper, aluminum, etc., and/or may be coated with a metal such as silver.

The gas injector assembly 104 includes one or more O-rings to provide a gas seal between various components of the gas injector assembly 104. For example, O-ring 140 is disposed between the gas injector 108 (e.g., in a groove) and the dielectric window 100. O-ring 144 is disposed between the RF shield 136 and the gas connection block 148. O-ring 152 is disposed between the gas injector 108 and the gas connection block 148.

The gas injector 108 includes a flange (e.g., an annular flange) 156 configured to secure the gas injector 108 within the insert 120 of the dielectric window 100. Because yttrium trioxide is brittle and more susceptible to damage, the height/depth of the flange 156 is greater than that of a gas injector comprising a material other than yttrium trioxide, wherein the flange 156 includes a groove for the O-ring 140 and may crack under pressure. For example, the vertical height of the flange 156 can be substantially equal to the depth of the opening 116 and the height of the insert 120 (e.g., within 0.05" or 1.25 mm). For example only, the height of the flange 156 is 0.5" (+/- 0.05"), or 12.7 mm. Thus, the upper surface of the flange 156 is flush with the upper surface of the insert 120.

The RF shield 136 includes a slot 160 configured to receive the body 164 of the nut assembly 132. For example, the slot 160 is disposed above the insert 120 (e.g., not within it). In addition, the lower flange 168 of the RF shield 136 is above the flange 156 and the insert 120.

Figures 2A, 2B, 2C, and 2D show alternative views of an example gas injector 200 according to the principles of the present disclosure, the gas injector 200 being composed of yttrioxide (e.g., solid yttrioxide or another material having a yttrioxide coating). For example, Figure 2A shows an isometric view of the gas injector 200. Figure 2B shows a cross-sectional view of the gas injector 200. Figure 2C shows a side view of the gas injector 200. Figure 2D shows a close-up view of the feature 204 shown in Figure 2B.

The foregoing description is intended to be illustrative only and is not intended to limit the disclosure, its application or use herein. The broad teachings of this disclosure can be implemented in many forms. Therefore, although this disclosure includes specific examples, other adjustments will become apparent upon study of the drawings, the specification, and the following patent application scope, so the true scope of this disclosure should not be limited to this. It should be understood that one or more steps in a method may be performed in a different order (or simultaneously) without changing the principles of this disclosure. Furthermore, although each embodiment is described above as having specific features, any one or more of these features described in relation to any embodiment of the present disclosure may be implemented in and/or in combination with the features of any other embodiment, even if the combination is not explicitly described. In other words, the embodiments described are not mutually exclusive, and substitution of one or more embodiments with another is still within the scope of the present disclosure.

Spatial and functional relationships between components (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including "connected," "fitted," "coupled," "adjacent," "adjacent," "on top," "above," "below," and "disposed." Unless explicitly described as "directly," when describing a relationship between a first and second component in the above disclosure, the relationship may be a direct relationship with no other intervening components between the first and second components, or an indirect relationship with one or more intervening components between the first and second components (spatially or functionally). As used herein, the term at least one of A, B, and C should be interpreted as using a non-exclusive "or" to express logic (A or B or C), and should not be interpreted as meaning "at least one of A, at least one of B, and at least one of C."

In some instances, the controller is part of a system, which may be part of one of the examples above. The system may include semiconductor processing equipment, including processing tools, chambers, platforms, and/or specific processing components (wafer pedestals, airflow systems, etc.). These systems may integrate electronics to control their operations before, during, and after processing of semiconductor wafers or substrates. The electronics may be referred to as a "controller" and may control various components or subcomponents of the system. The controller may be designed to control any of the processes disclosed herein, including process gas delivery, 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 settings, fluid delivery settings, position and operation settings, wafer transport into and out of tools and other transport tools and/or load locks connected to a particular system, depending on the processing requirements and/or system type.

Broadly speaking, a controller can be defined as an electronic product with various integrated circuits, logic, memory, and/or software that can accept instructions, send instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. The integrated circuits may include chips that store program instructions in the form of firmware, digital signal processors (DSPs), chips defined as special application integrated circuits (ASICs), and/or one or more microprocessors or microcontrollers that execute program instructions (such as software). Program instructions may be communicated to the controller in the form of various individual configurations (or program files) that define the operating parameters of a specific process to be executed on a semiconductor wafer or system. In some embodiments, the operating parameters may be part of a recipe defined by a process engineer to perform one or more process steps in the process of manufacturing one or more layers, material layers, metal layers, oxide layers, silicon crystal layers, silicon dioxide layers, surfaces, circuits, and/or dies of a wafer.

In some embodiments, the controller may be part of or coupled to a computer that is integrated with the system, coupled to the system, or otherwise networked to the system, or a combination of the above. For example, the controller may be in the "cloud" or part or all of a factory host computer, allowing remote access to wafer processes. The computer may be able to remotely connect to the system to monitor the progress of current manufacturing operations, view historical records of past manufacturing operations, view trends and performance matrices for multiple manufacturing operations, modify current process parameters, set process steps to continue a current process, or start a new process. In some examples, a remote computer (such as a server) can provide process recipes to the system through a network that may be a local area network or the Internet. The remote computer may include a user interface that allows for the entry or configuration of parameters and/or settings that are connected to the system from the remote computer. In some examples, the controller receives instructions in the form of data that specifies execution parameters for each process step to be performed during one or more operations. It will be appreciated that the parameters may be specific to the type of process to be performed and the type of tool with which the controller is configured to interface or control. Thus, as described above, the controller may be decentralized, such as by combining one or more individual controllers to collaborate and work toward a common purpose through networking, such as the process and control described herein. An example of a decentralized controller for this purpose may be one or more integrated circuits on a chamber connected to one or more integrated circuits located remotely (e.g., at a platform level or as part of a remote computer) that combine to control the process in the chamber.

Without limitation, example systems may include plasma etching chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel etching chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, or any other semiconductor processing system that may be associated with or used in the production and/or fabrication of semiconductor wafers.

As described above, the controller may communicate with one or more other tool circuits or modules, other tool components, group tools, other tool interfaces, adjacent tools, neighboring tools, tools throughout the fab, a host computer, another controller, or a material handling tool that transports wafer containers to or from tool locations and/or load ports within the semiconductor fabrication fab, depending on the process steps being performed by the tool.

104: Gas injector assembly

108: Gas injector

112: Central depression

116: Open mouth

120:Inlay

124: Open mouth

128: Gas outlet

132: Nut assembly

136:RF shielding

140: O-ring

144:O-ring

148: Gas connection block

152: O-ring

156: flange

160: Slot

164: Subject

168: Lower flange

Claims (19)

A component for a substrate processing chamber, the component comprising: a quartz dielectric window configured to be disposed in an upper surface of the substrate processing chamber; a recessed portion in the quartz dielectric window, wherein the recessed portion comprises a first opening, the first opening extending through the quartz dielectric window; a gas injector assembly comprising a gas injector, wherein the gas injector assembly is disposed in the recessed portion such that the gas injector extends through the first opening; and a seal disposed in a groove between the gas injector and the quartz dielectric window, wherein the gas injector is one of the following: (i) composed of yttrioxide; and (ii) comprises an outer surface having a yttrioxide coating. For example, a component for a substrate processing chamber as claimed in item 1 of the patent application, wherein the gas injector corresponds to a gas injector with a honeycomb arrangement including a plurality of gas outlets. The component for a substrate processing chamber as claimed in item 1 of the patent application further comprises an insert disposed in the recess, wherein the insert comprises a second opening and the gas injector extends through the second opening. For example, a component for a substrate processing chamber as claimed in item 3 of the patent application, wherein the second opening corresponds to a latch opening. For example, a component for a substrate processing chamber as defined in item 3 of the patent application, wherein the insert is made of at least one of plastic and quartz. The assembly for a substrate processing chamber as claimed in item 3 of the patent application further comprises a nut assembly configured to fix the gas injector assembly in the second opening. For example, the assembly for a substrate processing chamber in item 6 of the patent application scope, wherein the nut assembly is configured for a twist locking operation. For example, the assembly for a substrate processing chamber in item 6 of the patent application scope further includes a radio frequency shield disposed between the nut assembly and the gas injector. The component for a substrate processing chamber as in item 8 of the patent application further includes a seal disposed between the RF shield and a gas connection block of the gas injector assembly. For example, the component for a substrate processing chamber as claimed in item 8 of the patent application, wherein the RF shield includes a groove configured to receive a main body of the nut assembly. For example, the component for a substrate processing chamber as claimed in item 10 of the patent application, wherein the groove is arranged above the insert. As in claim 11, the assembly for a substrate processing chamber, wherein the gas injector comprises a flange disposed in the second opening, and a lower flange of the RF shield is located above (i) the flange of the gas injector and (ii) the insert. For example, a component for a substrate processing chamber as defined in item 1 of the patent application, wherein the seal is an O-ring. The component for a substrate processing chamber as claimed in claim 1 further includes an insert disposed in the recess, wherein: the insert includes a second opening, and the gas injector extends through the second opening; and the gas injector includes a flange disposed in the second opening. For example, in the component for a substrate processing chamber of claim 14, a height of the flange is substantially the same as at least one of: (i) a depth of the first opening, and (ii) a height of the insert. For example, in the component for a substrate processing chamber of claim 14, an upper surface of the flange is flush with an upper surface of the insert. A gas injector comprises: a flange configured to fix the gas injector to a dielectric window, wherein the flange comprises at least one groove located at the bottom of the flange and used to accommodate a sealing ring; a first set of gas outlets configured in a honeycomb arrangement at the bottom of the gas injector, and a second set of gas outlets configured radially outward of the first set of gas outlets; and wherein the gas injector comprises an outer surface having a yttrioxide coating, or the gas injector is composed of yttrioxide. The gas injector of claim 17 further comprises: a central recessed portion in the dielectric window, wherein the central recessed portion comprises a first opening, and the first opening extends through the dielectric window; an insert disposed in the central recessed portion, wherein the insert comprises a second opening; and a nut assembly configured to fix the gas injector assembly in the second opening, wherein the flange is disposed in the second opening. For example, in the gas injector of claim 18, a height of the flange is substantially equal to at least one of (i) a depth of the first opening and (ii) a height of the insert, so that an upper surface of the flange is flush with an upper surface of the insert.

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