Grid assembly of plasma processing apparatus

Abstract

The present disclosure provides a grid assembly for injecting process gas into a chamber. The grid assembly includes a gas inlet for delivering process gas to the grid assembly, a plurality of nozzles extending vertically through at least a portion of the grid assembly, and a plurality of layers arranged in a vertical stack. The plurality of layers includes: a top layer including one or more internal gas injection channels configured to receive process gas from the gas inlet; a bottom layer including a plurality of internal gas injection channels having one or more injection orifices configured to deliver process gas near a horizontal plane to one or more of the plurality of nozzles; and one or more sub-layers disposed between the top layer and the bottom layer, each of the one or more sub-layers including an increasing number of internal gas injection channels as the one or more sub-layers progress from the top layer to the bottom layer. The present disclosure also provides a plasma processing apparatus and a method of processing a workpiece.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 132,817, filed on December 31, 2020, entitled "Grid Assembly for Plasma Processing Apparatus", the entire content of which is incorporated herein by reference. This application claims the benefit of priority to U.S. Provisional Application No. 63 / 215,624, filed on June 28, 2021, entitled "Grid Assembly for Plasma Processing Apparatus", the entire content of which is incorporated herein by reference. Technical Field

[0003] The present disclosure generally relates to plasma processing apparatuses for processing workpieces, and more particularly, to grid assemblies for injecting process gases into a processing chamber and / or a plasma chamber. Background Art

[0004] Plasma processing is widely used in the semiconductor industry for deposition, etching, resist removal, and related processing of semiconductor wafers and other substrates. Plasma sources (such as microwave, ECR, inductively coupled, etc.) are typically used in plasma processing to generate high - density plasmas and reactive species for processing substrates. In plasma dry stripping processes, neutral species (such as radicals) of the plasma generated in a remote plasma chamber pass through a grid into the processing chamber to process workpieces, such as semiconductor wafers. In plasma etching processes, radicals, ions, and other species generated in the plasma directly exposed to the workpiece can be used to etch and / or remove materials on the workpiece. Summary of the Invention

[0005] Aspects and advantages of embodiments of the present disclosure will be set forth in part in the following description, or may be learned from the description, or may be learned through practice of the embodiments.

[0006] Aspects of the present disclosure relate to a grid assembly for injecting process gas into a chamber. The grid assembly includes a gas inlet for delivering process gas to the grid assembly, a plurality of nozzles extending vertically through at least a portion of the grid assembly, and a plurality of layers arranged in a vertical stack. The plurality of layers includes: a top layer including one or more internal gas injection channels configured to receive process gas from the gas inlet; a bottom layer including a plurality of internal gas injection channels having one or more injection orifices, wherein the injection orifices are configured to deliver process gas near a horizontal plane to one or more of the plurality of nozzles; and one or more sub-layers disposed between the top layer and the bottom layer, each of the one or more sub-layers including an increasing number of internal gas injection channels as the one or more sub-layers progress from the top layer to the bottom layer.

[0007] Aspects of the present disclosure also relate to a plasma processing apparatus for processing a workpiece. The plasma processing apparatus includes: a processing chamber; a workpiece support disposed within the processing chamber and configured to support the workpiece during processing; a plasma chamber separated from the processing chamber by a grid; and an inductively coupled plasma source configured to generate plasma in the plasma chamber. The grid includes a grid assembly that includes a gas inlet for delivering a first process gas to the grid assembly, a plurality of nozzles extending vertically through at least a portion of the grid assembly, and a plurality of layers arranged in a vertical stack. The plurality of layers includes: a top layer including one or more internal gas injection channels configured to receive the first process gas from the gas inlet; a bottom layer including a plurality of internal gas injection channels having one or more injection orifices configured to deliver the first process gas near a horizontal plane to one or more of the plurality of nozzles; and one or more sub-layers disposed between the top layer and the bottom layer, each of the one or more sub-layers including an increasing number of internal gas injection channels as the one or more sub-layers progress from the top layer to the bottom layer.

[0008] Aspects of the present disclosure also relate to a method for processing a workpiece in a plasma processing apparatus. The plasma processing apparatus includes a plasma chamber and a processing chamber separated by a grid. The processing chamber has a workpiece support. The grid includes a grid assembly that includes a gas inlet for delivering a first process gas to the grid assembly, a plurality of nozzles extending vertically through at least a portion of the grid assembly, and a plurality of layers arranged in a vertical stack. The plurality of layers includes: a top layer including one or more internal gas injection channels configured to receive the first process gas from the gas inlet; a bottom layer including a plurality of internal gas injection channels having one or more injection orifices configured to deliver the first process gas near a horizontal plane to one or more of the plurality of nozzles; and one or more sub-layers disposed between the top layer and the bottom layer, each of the one or more sub-layers including an increasing number of internal gas injection channels as the one or more sub-layers progress from the top layer to the bottom layer. The method includes: admitting a second process gas into the plasma chamber; generating one or more species from the second process gas using a plasma induced in the plasma chamber; admitting the first process gas via the grid assembly into the grid when the one or more species pass from the plasma chamber into the processing chamber; and exposing the workpiece to the one or more species to process the workpiece.

[0009] These and other features, aspects, and advantages of the various embodiments will be better understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with the description, serve to explain the related principles. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A detailed discussion of embodiments for those of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0011] Figure 1 An exemplary plasma processing apparatus according to an exemplary embodiment of the present disclosure is depicted;

[0012] Figure 2 An exemplary top perspective view of an exemplary grid assembly according to an exemplary embodiment of the present disclosure is depicted;

[0013] Figure 3 An exemplary side view of an exemplary grid assembly according to an exemplary embodiment of the present disclosure is depicted;

[0014] Figure 4 An exemplary cross-sectional view of an exemplary grid assembly according to an exemplary embodiment of the present disclosure is depicted;

[0015] Figure 5 An exemplary partial cross-sectional view of an exemplary grid assembly according to an exemplary embodiment of the present disclosure is depicted;

[0016] Figure 6 Depicts an exemplary cross-sectional view of an exemplary gate assembly according to an exemplary embodiment of the present disclosure;

[0017] Figure 7A Depicts an exemplary top view of an exemplary gate assembly according to an exemplary embodiment of the present disclosure;

[0018] Figure 7B Depicts Figure 7A a partial enlarged view of;

[0019] Figure 8A Depicts an exemplary top view of an exemplary sublayer of an exemplary gate assembly according to an exemplary embodiment of the present disclosure;

[0020] Figure 8B Depicts Figure 8A a partial enlarged view of;

[0021] Figure 9A Depicts an exemplary top view of an exemplary sublayer of an exemplary gate assembly according to an exemplary embodiment of the present disclosure;

[0022] Figure 9B Depicts Figure 9A a partial enlarged view of;

[0023] Figure 10A Depicts an exemplary top view of an exemplary sublayer of an exemplary gate assembly according to an exemplary embodiment of the present disclosure;

[0024] Figure 10B Depicts Figure 10A a partial enlarged view of;

[0025] Figure 11A Depicts an exemplary top view of an exemplary sublayer of an exemplary gate assembly according to an exemplary embodiment of the present disclosure;

[0026] Figure 11B Depicts Figure 11A a partial enlarged view of;

[0027] Figure 12A Depicts an exemplary top view of an exemplary sublayer of an exemplary gate assembly according to an exemplary embodiment of the present disclosure;

[0028] Figure 12B Depicts Figure 12A a partial enlarged view of;

[0029] Figure 13A Depicts an exemplary top view of an exemplary bottom layer of an exemplary gate assembly according to an exemplary embodiment of the present disclosure;

[0030] Figure 13B DepictsFigure 13A Partial enlarged view;

[0031] Figure 14 Depicts an exemplary enlarged cross-sectional view of an exemplary gate assembly in accordance with an exemplary embodiment of the present disclosure; and

[0032] Figure 15 Depicts an exemplary flowchart of an exemplary workpiece processing method in accordance with an exemplary embodiment of the present disclosure. Detailed Description

[0033] Exemplary aspects of the present disclosure relate to a gate assembly configured to provide uniform gas injection to a plasma processing apparatus. For example, the gate assembly can be used to provide more uniform process gas injection to a processing chamber or can be used to provide more uniform gas injection to a plasma chamber, such as in a plasma processing apparatus having a remote plasma source. The remote plasma source can include a plasma chamber and a processing chamber separated by a septum, the septum including the gate assembly. The septum can filter ions from the plasma such that neutral species pass through the septum to reach the processing chamber for exposure to a workpiece, such as a semiconductor wafer. In this regard, the gate assembly can define or be incorporated into the septum.

[0034] Plasma processing of workpieces (such as semiconductor wafers) is widely used and can be used to perform a variety of plasma-based processes. For example, a plasma etching process can be performed to remove one or more material layers or structures. A plasma deposition process can be used to deposit one or more material layers on a workpiece. In addition, plasma-based surface treatment processes can be used to alter the surface morphology or chemical composition of certain layers present on a workpiece. However, while plasma processing has proven useful for certain processing processes, the fact remains that plasma processing can sometimes negatively impact the overall uniformity of a workpiece and can also lead to device damage. In addition, there is a need to provide more refined plasma processing processes to avoid device damage.

[0035] In addition, in some applications, the process gas can be remotely plasma-activated by a carrier gas from a plasma chamber located above the septum. In certain cases, the gate assembly can be used to inject the process gas into the plasma chamber itself such that the injected process gas can be activated by a plasma induction source. In such embodiments, the gate assembly can define or be incorporated into a showerhead or gas delivery system generally configured to deliver the process gas to the plasma chamber. However, in other cases, the process gas should be injected at a location in the reaction region between the septum and the workpiece at or below the septum level (such as post-plasma gas injection) to shield the RF power used to generate the plasma.

[0036] Accordingly, on the one hand, the present specification provides a grid assembly for a plasma processing apparatus. The grid assembly includes: a gas inlet configured to deliver a process gas to the grid assembly; a plurality of nozzles extending vertically through at least a portion of the grid assembly; and a plurality of layers arranged in a vertical stack. The plurality of layers includes: a top layer including one or more internal gas injection channels configured to receive the process gas from the gas inlet; a bottom layer including a plurality of internal gas injection channels having one or more injection orifices configured to deliver the process gas near a horizontal plane to one or more of the plurality of nozzles; and one or more sub-layers disposed between the top layer and the bottom layer, each of the one or more sub-layers including an increasing number of internal gas injection channels as the one or more sub-layers progress from the top layer to the bottom layer. The grid assembly can be incorporated into a septum or a showerhead of a suitable plasma processing apparatus.

[0037] The grid assembly according to an exemplary embodiment of the present disclosure can provide many benefits and technical effects. For example, the grid assembly can more uniformly distribute the process gas to the processing chamber while maintaining a grounded state before entering one or more nozzles provided within the grid assembly. Thus, the process gas can be shielded from the RF power used to activate the process gas in the plasma chamber and, instead, can remain grounded until it is mixed with one or more species of the remote plasma from the nozzles in the grid assembly. Such a configuration prevents the process gas from passing through the discharge or plasma heating zone in the plasma chamber and can facilitate a more refined plasma processing of the workpiece. In addition, the grid assembly can better distribute the process gas more uniformly to the wafer. Accordingly, workpiece uniformity can be improved and workpiece damage can be avoided.

[0038] For purposes of illustration and discussion, aspects of the present disclosure are discussed with reference to a grid assembly used in a remote plasma processing apparatus. Those of ordinary skill in the art will understand, using the disclosure provided in the present specification, that the techniques according to the exemplary aspects of the present disclosure can be used, for example, as a showerhead to directly deliver a process gas to a processing chamber and / or a plasma chamber (e.g., a chamber of an upper electrode in a capacitively coupled plasma source (CCP)) of a plasma processing apparatus. In such an embodiment, the grid assembly may or may not have through-holes for the nozzles. In such an embodiment, the nozzles may be provided only in a lower layer or at the bottom of the assembly to uniformly distribute the process gas to the processing chamber and / or the plasma chamber.

[0039] Reference will now be made in detail to the embodiments, one or more examples of which are illustrated in the drawings. Each example is provided for the purpose of explaining the embodiments and is not a limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments without departing from the scope or spirit of the disclosure. For example, features shown or described as part of one embodiment can be used with another embodiment to yield yet another embodiment. Accordingly, aspects of the disclosure are intended to embrace such modifications and variations.

[0040] For purposes of illustration and discussion, aspects of the disclosure are discussed with reference to a "workpiece", "wafer", or semiconductor wafer. Those of ordinary skill in the art will understand, using the disclosure provided herein, that the exemplary aspects of the disclosure can be used in association with any semiconductor workpiece or other suitable workpiece. Additionally, the term "about" when used in conjunction with a numerical value is intended to refer to within ten percent (10%) of the stated numerical value. A "chuck" refers to any structure that can be used to support a workpiece. A "remote plasma" refers to a plasma generated remote from the workpiece, such as a plasma generated in a plasma chamber separated from the workpiece by a baffle. A "direct plasma" refers to a plasma that is directly exposed to the workpiece, such as a plasma generated in a processing chamber having a chuck operable to support the workpiece.

[0041] Figure 1 An exemplary plasma processing apparatus 500 that can be used to implement a workpiece processing process in accordance with an exemplary embodiment of the disclosure is depicted. The plasma processing apparatus includes a processing chamber 110 and a plasma chamber 120 separated from the processing chamber 110. The processing chamber 110 includes a workpiece support 112 or chuck, which is operable to hold a workpiece 114 to be processed, such as a semiconductor wafer. In this exemplary illustration, a plasma 502 is generated in the plasma chamber 120 (i.e., the plasma generation region) by an inductively coupled plasma source 135, and a desired species is transported through a channel from the plasma chamber 120 to the surface of the workpiece 114 via a baffle assembly 200.

[0042] The plasma chamber 120 includes a dielectric sidewall 122 and a top 124. The dielectric sidewall 122, the top 124, and the grid 200 define the plasma chamber interior 125. The dielectric sidewall 122 can be formed of a dielectric material, such as formed of quartz and / or alumina. The dielectric sidewall 122 can be formed of a ceramic material. The inductively coupled plasma source 135 can include an induction coil 130 disposed near the dielectric sidewall 122 surrounding the plasma chamber 120. The induction coil 130 is coupled to an RF power generator 134 through a suitable matching network 132. Process gas from a gas supply source 150 and an annular gas distribution channel 151 or other suitable gas introduction mechanism (such as the grid assembly disclosed in this specification) can be provided into the chamber interior, which will be further discussed below. When the induction coil 130 is excited by RF power from the RF power generator 134, a plasma 502 can be generated in the plasma chamber 120. In a particular embodiment, the plasma processing apparatus 500 can include an optional grounded Faraday shield 128 to reduce the capacitive coupling from the induction coil 130 to the plasma 502. Although one induction coil 130 is shown, the present disclosure is not limited thereto. In fact, any number of induction coils or induction coil assemblies can be used herein to generate a plasma in the plasma chamber 120.

[0043] Figure 1 The exemplary plasma processing apparatus 500 is operable to generate a first plasma 502 (e.g., remote plasma) in the plasma chamber 120 and a second plasma 504 (e.g., direct plasma) in the processing chamber 110. The first plasma 502 can be generated by an inductively coupled plasma source. The second plasma 504 can be generated by, for example, a capacitively coupled plasma source (e.g., biased).

[0044] More specifically, the plasma processing apparatus 500 includes a bias source having a bias electrode 510 in the workpiece support 112. The bias electrode 510 can be coupled to an RF power generator 514 through a suitable matching network 512. When the bias electrode 510 is excited by RF energy, a second plasma 504 can be generated from the filtered mixture or process gas in the processing chamber 110 for direct exposure to the workpiece 114. The processing chamber 110 can include an exhaust port 516 for exhausting gas from the processing chamber 110.

[0045] In some embodiments, the workpiece support 112 is configured such that a DC bias can be applied to the workpiece 114. In some embodiments, a DC power supply is applied to the bias electrode 510 located in the workpiece support 112. A DC bias can be applied to generate an electric field such that certain species can be attracted to and / or accelerated towards the workpiece 114. By applying a DC bias to the workpiece 114, the flux of certain ionic species can be controlled. This can facilitate the growth of a polymer film on the structure of the workpiece 114 or radical etching. In some embodiments, the DC bias applied or provided to the bias electrode is from about 50 W to about 150 W. The DC bias can be applied to the workpiece 114 to accelerate certain species from the first plasma 502 and / or the second plasma 504 towards the workpiece 114.

[0046] As Figure 1 shown, according to an exemplary aspect of the present disclosure, the apparatus 500 may include a gas delivery system 155 configured to deliver a process gas to the plasma chamber 120, for example, via a gas distribution channel 151 or other distribution systems (such as a showerhead). The gas delivery system 155 may include a plurality of feed gas lines 159. The feed gas lines 159 can be controlled using valves 158 and / or gas flow controllers 185 to deliver a desired amount of gas into the processing chamber 120 as a process gas. The gas delivery system 155 can be used to deliver any suitable process gas. Exemplary process gases include oxygen-containing gases (such as O 2 、O 3 、N 2 O、H 2 O), hydrogen-containing gases (such as H 2 、D 2 ), nitrogen-containing gases (such as N 2 、NH 3 、N 2 O), fluorine-containing gases (such as CF 4 、C 2 F 4 、CHF 3 、CH 2 F 2 、CH 3 F、SF 6 、NF 3 ), hydrocarbon-containing gases (such as CH 4 ) or combinations thereof. Additional feed gas lines containing other gases can be added as needed. In some embodiments, the process gas can be mixed with what can be referred to as a "carrier" gas (such as He, Ar, Ne, Xe, or N 2) inert gas mixing. The control valve 158 can be used to control the flow rate of each feed gas line to introduce process gas into the plasma chamber 120. In an embodiment, the gas delivery system 155 can be controlled by a gas flow controller 185.

[0047] As Figure 1 shown, the baffle 200 separates the plasma chamber 120 from the processing chamber 110. The baffle 200 can be used to perform ion filtration on the mixture generated by the plasma in the plasma chamber 120 to generate a filtered mixture. The filtered mixture can be exposed to the workpiece 114 in the processing chamber 110. Additionally, the baffle 200 can include a baffle assembly 202, as will be further disclosed in this specification. The baffle assembly 202 can be used to supply one or more process gases to the filtered mixture and / or the processing chamber 110. In certain embodiments, additionally and / or alternatively, the baffle 200 can be a multi-plate baffle. For example, the baffle 200 can include a first baffle plate and a second baffle plate spaced apart from each other in a parallel relationship. The first baffle plate and the second baffle plate can be spaced a certain distance apart.

[0048] The first baffle plate can have a first baffle pattern with a plurality of holes. The second baffle plate can have a second baffle pattern with a plurality of holes. The first baffle pattern can be the same as or different from the second baffle pattern. Charged particles can recombine on the walls in their paths through the holes of each baffle plate in the baffle. Neutral species (such as radicals) can flow relatively freely through the holes in the first baffle plate and the second baffle plate. The size of the holes and the thickness of each baffle plate affect the transmission rates of charged particles and neutral particles.

[0049] In some embodiments, the first baffle plate can be made of a metal (such as aluminum) or other conductive material and / or the second baffle plate can be made of a conductive material or a dielectric material (such as quartz, ceramic, etc.). In some embodiments, the first baffle plate and / or the second baffle plate can be made of other materials, such as made of silicon or silicon carbide. In the case where the baffle plate is made of a metal or other conductive material, the baffle plate can be grounded.

[0050] As noted, the baffle 200 can include a baffle assembly 202. Refer to Figures 2 - 14 The baffle assembly 202 will be further discussed. For example, Figure 2 shows a top view of the baffle assembly 200, showing one or more nozzles 204 distributed throughout the baffle assembly 200. As shown, one or more nozzles 204 can be through nozzles extending from the top surface of the baffle assembly 200 to the bottom surface of the baffle assembly 200. Thus, when plasma 502 is generated in the plasma chamber 120, one or more species can flow from the plasma chamber 120 through one or more nozzles 204 and into the processing chamber 110. Figure 2 Also shown is a gas inlet 206 for supplying process gas to the baffle assembly 202.Figure 3 shows a side view of the grid assembly 202 including a gas inlet 206, while Figure 4 shows a cross-sectional view of the grid assembly 202 including a gas inlet 206. Additionally, as Figure 4 shown, the nozzle 204 extends from the top surface 210 of the grid assembly 202 to the bottom surface 212 of the grid assembly 202. Without being limited to any particular configuration, in some embodiments, the top surface 210 of the grid assembly 202 is arranged closer to the plasma chamber 120, while the bottom surface 212 of the grid assembly 202 is arranged closer to the processing chamber 110. As shown, in Figure 4 , the grid assembly further includes one or more internal gas injection channels 220 (e.g., a plurality of internal gas injection channels 220) disposed throughout the grid assembly 202.

[0051] As Figure 5 shown, the grid assembly 202 may include multiple layers. In an embodiment, the multiple layers may be integrally formed such that the grid assembly 202 presents an integral structure having one or more internal gas injection channels 220 distributed therein. For example, in some embodiments, the grid assembly may include a top layer 224 that generally defines a portion of the top surface 210 of the grid assembly 202 and a bottom layer 226 that generally defines a portion of the bottom surface 212 of the grid assembly 202. One or more sub-layers 228 may be disposed between the top layer 224 and the bottom layer 226. For example, in an embodiment, the grid assembly 202 includes one sub-layer 228, while in other embodiments, the grid assembly 202 includes more than one sub-layer 228, such as at least two sub-layers 228, such as at least three sub-layers 228, such as at least four sub-layers 228, such as at least five sub-layers 228, such as at least six sub-layers 228, etc. The number of sub-layers used may depend on the total number and configuration of the internal gas injection channels 220 and / or the nozzles 204, which will be discussed further below. For example, as Figure 5 shown, the grid assembly includes a top layer 224, a bottom layer 226, and at least five sub-layers (228a, 228b, 228c, 228d, 228e). As Figure 5 shown, the gas inlet 206 delivers process gas to the top layer 224.

[0052] As further referenced Figures 7A - 13AAs will be discussed, each layer (e.g., top layer 224, bottom layer 226, and sub-layer 228) includes one or more internal gas injection channels 220 disposed therein. Generally, the internal gas injection channels 220 are disposed in the gate assembly 202 in a branched configuration and continue to branch continuously as they progress from the top layer 224 down through the layers to the bottom layer 226, whereupon reaching the bottom layer 226, the internal gas injection channels 220 deliver process gas to one or more of the plurality of nozzles 204 (e.g., such as all nozzles) via injection orifices 250 surrounding a horizontal plane. Reference will now be made to Figures 7A - 13A Embodiments of each layer (e.g., top layer 224, bottom layer 226, and sub-layer 228) are discussed, each of which shows a top view and / or enlarged view of each layer. Such embodiments are exemplary in nature, and other embodiments may be used in the gate assembly 202 disclosed herein. For example, as shown in the representative figures, the branches may be quadruplets; however, any number of branches or branch configurations may be used.

[0053] Figure 7A and Figure 7B An exemplary top layer 224 for the gate assembly 202 is shown. For example, the top layer 224 includes one or more internal gas injection channels 220 configured to receive process gas from a gas inlet 206. As shown, the top layer 224 includes one internal gas injection channel 220 that continues across the horizontal plane of the top layer 224 and does not intersect or interact with any of the plurality of nozzles 204 disposed therein. The internal gas injection channel 220 in the top layer 224 may run from the gas inlet 206 to generally the center of the top layer 224 such that process gas may be supplied to the center of the top layer 224. As shown, the top layer 224 includes only one internal gas injection channel; however, the top layer 224 may include more than one internal gas injection channel 220 for distributing gas across the entire top layer 224.

[0054] Figure 8A and Figure 8BAn exemplary sub-layer 228a adjacent to the bottom surface of the top layer 224 is shown. In other words, the sub-layer 228a is located below the top layer 224 in the z direction. As shown, the sub-layer 228a includes four internal gas injection channels 220 branching out from the center of the sub-layer 228. For example, the four internal gas injection channels 220 provided in the sub-layer 228a are configured to receive process gas from the internal gas injection channels 220 typically disposed around the center of the sub-layer 228a in the top layer 224. In an embodiment, at the end 230 of the internal gas injection channel 220, each of the internal gas injection channels in the internal gas injection channel 220 further branches into one or more internal gas injection channels 220. For example, as shown, extending from the initially four internal gas injection channels 220 are three additional branches of the internal gas injection channels 220. Although at least three additional branches of the internal gas injection channels 220 are shown, the present disclosure is not limited thereto. In fact, the branches can be branches of at least two internal gas injection channels 220, at least three internal gas injection channels 220, at least four internal gas injection channels 220, at least five internal gas injection channels 220, etc. Further, as shown, in an embodiment, none of the internal gas injection channels 220 in the sub-layer 228a contact or intersect any of the nozzles 204 disposed therein.

[0055] Figure 9A and Figure 9B An exemplary sub-layer 228b adjacent to the bottom surface of the sub-layer 228a is shown. In other words, the sub-layer 228b is located below the sub-layer 228a in the z direction. As shown, the sub-layer 228b includes a plurality of internal gas injection channels 220. Each of the internal gas injection channels 220 is supplied with gas from the end of a branch of the internal gas injection channels 220 provided in the sub-layer 228a. For example, as specifically Figure 9B shown, the center 240 of the branched internal gas injection channels 220 can be supplied with gas from one of the ends of the internal gas injection channels 220 provided in the sub-layer 228a. Further, as shown, the internal gas injection channels 220 of the sub-layer 228b branch out from the center 240 and can include various branching patterns or numbers of branches. For example, as shown, the branches can include at least two internal gas injection channels 220, such as at least three internal gas injection channels 220, such as at least four internal gas injection channels 220, such as at least five internal gas injection channels. As shown, in an embodiment, none of the internal gas injection channels 220 in the sub-layer 228b contact or intersect any of the nozzles 204 disposed therein.

[0056] Figure 10A and Figure 10BAn exemplary sub-layer 228c adjacent to the bottom surface of the sub-layer 228b is shown. In other words, the sub-layer 228c is located below the sub-layer 228b in the z direction. As shown, the sub-layer 228c includes a plurality of internal gas injection channels 220. Each of the internal gas injection channels 220 is supplied with gas from an end of a branch of the internal gas injection channels 220 provided in the sub-layer 228b. For example, as specifically Figure 10B shown, the center 240 of the internal gas injection channel 220 may be supplied with gas from one of the ends of the internal gas injection channels 220 provided in the sub-layer 228b. In addition, as shown, the internal gas injection channels 220 of the sub-layer 228c branch out from the center 240 and may include various branching patterns or numbers of branches. For example, as shown, the branches may include at least two internal gas injection channels 220, such as at least three internal gas injection channels 220, such as at least four internal gas injection channels 220, such as at least five internal gas injection channels. As shown, in an embodiment, none of the internal gas injection channels 220 in the sub-layer 228c contact or intersect any of the nozzles 204 provided therein.

[0057] Figure 11A and 11B An exemplary sub-layer 228d adjacent to the bottom surface of the sub-layer 228c is shown. In other words, the sub-layer 228d is located below the sub-layer 228c in the z direction. As shown, the sub-layer 228d includes a plurality of internal gas injection channels 220. Each of the internal gas injection channels 220 is supplied with gas from an end of a branch of the internal gas injection channels 220 provided in the sub-layer 228c. For example, as specifically Figure 11B shown, the center 240 of the internal gas injection channel 220 may be supplied with gas from one of the ends of the internal gas injection channels 220 provided in the sub-layer 228c. In addition, as shown, the internal gas injection channels 220 of the sub-layer 228d branch out from the center 240 and may include various branching patterns or numbers of branches. For example, as shown, the branches may include at least two internal gas injection channels 220, such as at least three internal gas injection channels 220, such as at least four internal gas injection channels 220, such as at least five internal gas injection channels. As shown, in an embodiment, none of the internal gas injection channels 220 in the sub-layer 228d contact or intersect any of the nozzles 204 provided therein.

[0058] Figure 12A and 12BIllustrated is an exemplary sub-layer 228e adjacent to the bottom surface of the sub-layer 228d. In other words, the sub-layer 228e is located below the sub-layer 228d in the z-direction. As shown, the sub-layer 228e includes a plurality of internal gas injection channels 220. Each of the internal gas injection channels 220 is supplied with gas from an end of a branch of the internal gas injection channels 220 provided in the sub-layer 228d. For example, as particularly Figure 12B shown, the center 240 of the internal gas injection channel 220 may be supplied with gas from one of the ends of the internal gas injection channels 220 provided in the sub-layer 228d. As shown, the center 240 of the internal gas injection channel 220 supplies gas to at least four internal gas injection channels 220, and then each internal gas injection channel 220 supplies process gas to one or more nozzles 204 via a gas injection orifice 250. Thus, the internal gas injection channel 220 having four branches extends between the center 240 and the nozzles 204 to supply process gas to at least four nozzles 204. However, the present disclosure is not limited thereto. The internal gas injection channels 220 of the sub-layer 228e may branch out from the center 240 and may include various branching patterns or numbers of branches. For example, as shown, the branches may include at least two internal gas injection channels 220, such as at least three internal gas injection channels 220, such as at least four internal gas injection channels 220, such as at least five internal gas injection channels. As shown, in an embodiment, each end 230 of the internal gas injection channels 220 in the sub-layer 228e contacts a nozzle 204 provided therein.

[0059] Figure 13A and Figure 13B Illustrated is an exemplary bottom layer 226 adjacent to or integrally formed with the bottom surface of the sub-layer 228e. In other words, the bottom layer 226 is located below the sub-layer 228e in the z-direction. As shown, the bottom layer 226 includes a plurality of nozzles 204. One or more injection orifices 250 that are joined to the internal gas injection channels 220 of the sub-layer 228e are joined to the nozzles 204 to deliver process gas to the nozzles 204. As previously described, the nozzles 204 provide an opening around the top surface of the top layer 224 and extend in the z-direction through the grid assembly 202, where one or more openings are provided around the bottom surface of the bottom layer 226. Thus, although the nozzles 204 may be formed in any shape, as shown, they are generally columnar extensions having continuous sidewalls extending parallel to the z-direction. In an embodiment, one or more gas injection orifices 250 are configured to intersect the sidewalls of the nozzles 204 around a plane perpendicular to the z-direction. Thus, the gas injection orifices 250 are configured to inject or deliver process gas to the nozzles 204 around a horizontal direction (e.g., in a direction generally perpendicular to the z-direction).

[0060] As Figures 7A - 13BAs shown, in some embodiments, each of one or more sub-layers 228 generally includes an increasing number of internal gas injection channels 220 as the sub-layer 228 progresses downward from the top layer 224 to the bottom layer 226. That is, the topmost sub-layer (e.g., sub-layer 228a adjacent to the top layer 224) includes the least number of internal gas injection channels 220, while the bottommost sub-layer (e.g., sub-layer 228e adjacent to the bottom layer 226) includes the most number of internal gas injection channels 220. In an embodiment, the bottom layer 226 includes more internal gas injection channels 220 compared to the top layer 224 and / or other sub-layers 228.

[0061] Importantly, the number of internal gas injection channels 220 provided in the sub-layer 228 can be determined based on the number of desired sub-layers between the top layer 224 and the bottom layer 226 and / or the number of nozzles 204 provided in the gate assembly 202. For example, in some embodiments, if additional sub-layers 228 are added, the number of internal gas injection channels 220 in each sub-layer 228 can be reduced. While in other embodiments, if the number of sub-layers 228 is reduced, the number of internal gas injection channels 220 in each sub-layer 228 can be increased. Additionally, if the number of nozzles 204 is reduced, the number of internal gas injection channels 220 in the sub-layer 228 can be reduced and / or the number of sub-layers 228 can be reduced. Similarly, in some embodiments, if the number of nozzles 204 is increased, the number of internal gas injection channels 220 in the sub-layer can be increased and / or the number of sub-layers 228 can be increased. Based on the number of nozzles 204 and / or sub-layers 204, the branching pattern of the internal gas injection channels 220 can be similarly modified or varied (e.g., increased or decreased).

[0062] Figure 14 A cross-sectional view of an exemplary gate assembly 202 is shown. As shown, the gate assembly 202 includes a plurality of nozzles 204 and internal gas injection channels 220 disposed within the gate assembly 202. Each of the internal gas injection channels 220 in the internal gas injection channels 220 is connected by a sub-layer 228 therein and is configured to supply process gas to the nozzles 204 via one or more gas injection orifices 250. The spacing and arrangement of the internal gas injection channels 220 can ensure that the flow delivery of the process gas to each nozzle 204 is substantially uniform and / or includes substantially equal flow conductances. Thus, in addition to patterning the internal gas injection channels 220, the configuration of the layers (e.g., the top layer 224, the bottom layer 226, and the sub-layers 228) is configured to ensure that each of the nozzles 204 is supplied with an equal flow rate of process gas. Advantageously, the gate assembly 202 can be used to uniformly provide process gas around the surface area of the gate while supplying the process gas from only one gas inlet. This eliminates the need for multiple gas inlets to supply the process gas more uniformly.

[0063] In addition, aspects of the present disclosure provide a showerhead assembly 202 having the ability to provide process gas injection via a horizontal plane that is RF power shielded in a delivery path. The showerhead assembly 202 can be metal and / or dielectric material. In certain embodiments, the showerhead assembly 202 can be encapsulated in a metal housing that has matching nozzle holes on both the top and bottom or only one side of the top or bottom. The gas inlet 206 for injecting process gas into the showerhead assembly 202 can be on the top, bottom, or side of the showerhead assembly 202.

[0064] In an embodiment, for each process gas delivery path from the gas inlet 206 to each nozzle 204 at the bottom of the showerhead assembly 202, the gas flow has approximately equal conductance for all nozzles 204 (e.g., the process gas delivered to the nozzles 204 at the gas injection orifice 250 has approximately equal conductance). In certain embodiments, there may be some edge effects around the perimeter of the showerhead assembly 202 where some of the internal gas injection channels 220 can deliver process gas to only one nozzle, or two nozzles, or three nozzles, which can make their conductances different. This can be reduced by making the diameter of the nozzle region larger than the diameter of the workpiece (e.g., for a 300 mm workpiece, the diameter is greater than 300 mm).

[0065] Although not shown, in certain embodiments, the showerhead assembly 202 can be used as part of a showerhead assembly in the apparatus 500 for delivering gas from a gas delivery system 150 into the plasma chamber 120. However, in such embodiments, the showerhead assembly can include or not include nozzles that extend in the z - direction through the entire showerhead assembly 202. Instead, one or more nozzles can be located on the bottom surface of the showerhead assembly 202 and can receive process gas from one or more of the internal gas injection channels 220 described in this specification. Additionally, in other embodiments, the showerhead assembly 202 can be used as a showerhead in a plasma processing apparatus having a processing chamber without a remote plasma chamber. In such embodiments, the plasma can be generated directly in the processing chamber and exposed to the workpiece. In such embodiments, the showerhead assembly 202 can be used to supply process gas into the processing chamber as described in this specification. Additionally, in such embodiments, the showerhead assembly 202 can include or not include nozzles that extend through the entire showerhead assembly 202 in the z - direction, as described above.

[0066] Figure 15 A flowchart of an exemplary method (400) in accordance with an exemplary aspect of the present disclosure is depicted. Method (400) will be discussed with reference to the exemplary Figure 1 plasma processing apparatus 500 illustrated. Method (400) can be implemented in any suitable plasma processing apparatus. Figure 1Illustrates steps performed in a particular order for purposes of illustration and discussion. Those of ordinary skill in the art, using the disclosure provided in this specification, will understand that the various steps of any method described in this specification can be omitted, extended, performed simultaneously, rearranged, and / or modified in various ways without departing from the scope of the present disclosure. Additionally, various steps (not shown) can be performed without departing from the scope of the present disclosure.

[0067] At (402), the method can include placing workpiece 114 in processing chamber 110 of plasma processing apparatus 500. Processing chamber 110 can be separated from plasma chamber 120 (e.g., by partition 200 including grid assembly 202). For example, the method can include placing workpiece 114 on workpiece support 112 in processing chamber 110. Grid assembly 202 can include a plurality of nozzles extending vertically through at least a portion of the grid assembly and a plurality of vertically stacked layers. The plurality of layers includes: a top layer including one or more internal gas injection channels configured to receive a first process gas from a gas inlet; a bottom layer including a plurality of internal gas injection channels having one or more injection orifices configured to deliver process gas near a horizontal plane to one or more of the plurality of nozzles; and one or more sub-layers disposed between the top layer and the bottom layer, each of the one or more sub-layers including an increasing number of internal gas injection channels as the one or more sub-layers progress from the top layer to the bottom layer.

[0068] At (404), the method can include admitting a second process gas into plasma chamber 120. For example, gas delivery system 150 can be used to admit one or more suitable process gases into plasma chamber 120. In certain embodiments, grid assembly 202 can be used to deliver process gas to plasma chamber 120. For example, in certain embodiments, grid assembly 202 can be configured as a showerhead connected to gas delivery system 150 to deliver process gas to plasma chamber 120. In such embodiments, grid assembly 202 may not include nozzle 204 extending through the entire grid assembly 202, but may instead include only one or more nozzles located in one of the bottom layers of grid assembly 202 for delivering process gas to plasma chamber 120.

[0069] At (406), the method can include generating one or more species from a second process gas using a plasma induced in plasma chamber 120. For example, induction coil 130 can be energized with RF power from RF power generator 134 to generate plasma 502 in plasma chamber 120. Plasma 502 can include one or more species, such as charged particles and / or neutral species. The one or more species can pass through one or more nozzles 204 in the grill assembly 202 of grill 200 and can enter process chamber 110 to expose workpiece 114 to the one or more species.

[0070] At (408), the method includes admitting a first process gas into grill 200 via grill assembly 202, for example when the one or more species are being passed from plasma chamber 120 into process chamber 110. For example, as disclosed, the grill assembly can include a plurality of nozzles and one or more internal gas injection channels 220 disposed in various layers throughout grill assembly 202. The internal gas injection channels 220 can be used to provide process gas and / or provide a mixed process gas having the one or more species as the one or more species pass through nozzles 204. Using the disclosed grill assembly 202 provides for substantially uniform flow delivery of the first process gas to each of the plurality of nozzles 204 and / or includes substantially equal flow conductances.

[0071] In certain embodiments, grill 200 can be used to filter ions generated by the plasma. Grill 200 can have a plurality of holes. Charged particles (e.g., ions) can recombine on the walls in their path through the plurality of holes. Neutral species (e.g., radicals) can pass through the holes. Thus, grill 200 including grill assembly 202 can be used to form a filtered mixture exposed to workpiece 114 in the process chamber for processing the workpiece. Additionally, in some embodiments, workpiece 114 can be exposed to the one or more species for processing workpiece 114.

[0072] At (410), the method can include removing the workpiece from the process chamber. For example, workpiece 114 can be removed from workpiece support 112 in process chamber 110. Then, the plasma processing apparatus can be adjusted for processing of future other workpieces.

[0073] Although the subject matter has been described in detail with respect to specific exemplary embodiments thereof, it should be understood that those skilled in the art can readily generate such changes, variations, and equivalents upon obtaining an understanding of the foregoing. Accordingly, the scope of the disclosure is presented by way of example and not by way of limitation, and the subject matter disclosure does not exclude inclusion of such modifications, variations, and / or additions to the subject matter that would be apparent to a person of ordinary skill in the art.

Claims

1. A gate assembly for injecting process gas into a chamber, comprising: a gas inlet for delivering the process gas to the gate assembly; a plurality of nozzles extending vertically through the entire gate assembly; and a plurality of layers arranged vertically in a stack, the plurality of layers comprising: a top layer including one or more internal gas injection channels configured to receive the process gas from the gas inlet; a bottom layer including a plurality of internal gas injection channels having one or more injection orifices configured to deliver the process gas near a horizontal plane to one or more of the plurality of nozzles; and a plurality of sub-layers disposed between the top layer and the bottom layer, each of the plurality of sub-layers including an increasing number of internal gas injection channels as the plurality of sub-layers progress from the top layer to the bottom layer.

2. The gate assembly according to claim 1, wherein the plurality of sub-layers includes at least five sub-layers.

3. The gate assembly according to claim 1, wherein the top layer, the bottom layer and the plurality of sub-layers are integrally formed.

4. The gate assembly according to claim 1, wherein compared with the top layer and / or the plurality of sub-layers, the bottom layer includes more internal gas injection channels.

5. The gate assembly according to claim 1, wherein the gate assembly comprises a dielectric material.

6. The gate assembly according to claim 1, wherein the gate assembly comprises a metallic material.

7. The gate assembly according to claim 1, wherein the chamber includes a processing chamber.

8. The gate assembly according to claim 1, wherein the chamber includes a plasma chamber.

9. The gate assembly according to claim 1, wherein the flow delivery of the process gas to each of the plurality of nozzles is substantially uniform and / or includes substantially equal flow conductances.

10. The gate assembly according to claim 1, wherein the gate assembly is incorporated into a septum for a plasma processing apparatus.

11. A plasma processing apparatus for processing a workpiece, the plasma processing apparatus comprising: a processing chamber; a workpiece support disposed in the processing chamber and configured to support the workpiece during processing; a plasma chamber separated from the processing chamber via a septum; and an inductively coupled plasma source configured to generate plasma in the plasma chamber, wherein the septum includes a gate assembly, the gate assembly comprising: a gas inlet for delivering a first process gas to the gate assembly; a plurality of nozzles extending vertically through the entire gate assembly; and a plurality of layers arranged vertically in a stack, the plurality of layers comprising: a top layer including one or more internal gas injection channels configured to receive the first process gas from the gas inlet; a bottom layer including a plurality of internal gas injection channels having one or more injection orifices configured to deliver the first process gas near a horizontal plane to one or more of the plurality of nozzles; and A plurality of sub-layers are disposed between the top layer and the bottom layer, and each sub-layer of the plurality of sub-layers includes internal gas injection channels that increase in number as the plurality of sub-layers progress from the top layer to the bottom layer.

12. The plasma processing apparatus according to claim 11, wherein, the one or more nozzles of the gate assembly are configured to allow one or more substances generated in the plasma to move from the plasma chamber to the processing chamber.

13. The plasma processing apparatus according to claim 11, wherein, the plasma processing apparatus further includes a gas delivery system configured to deliver one or more second process gases to the plasma chamber.

14. The plasma processing apparatus according to claim 11, wherein, the top layer, the bottom layer, and the plurality of sub-layers are integrally formed.

15. The plasma processing apparatus according to claim 11, wherein, the plurality of sub-layers includes at least five sub-layers.

16. The plasma processing apparatus according to claim 11, wherein, compared to the top layer and / or the plurality of sub-layers, the bottom layer includes more internal gas injection channels.

17. The plasma processing apparatus according to claim 11, wherein, each of the one or more internal gas injection channels in the bottom layer is configured to supply the first process gas to at least four nozzles.

18. A method for processing a workpiece in a plasma processing apparatus, the plasma processing apparatus having a plasma chamber and a processing chamber separated by a septum, the processing chamber having a workpiece support, the septum including a gate assembly, the gate assembly comprising: a gas inlet for delivering a first process gas to the gate assembly; a plurality of nozzles extending vertically through the entire gate assembly; and a plurality of layers arranged vertically in a stack, the plurality of layers including a top layer including one or more internal gas injection channels configured to receive the first process gas from the gas inlet; a bottom layer including a plurality of internal gas injection channels having one or more injection orifices configured to deliver the first process gas near a horizontal plane to one or more of the plurality of nozzles; and a plurality of sub-layers disposed between the top layer and the bottom layer, each sub-layer of the plurality of sub-layers including internal gas injection channels that increase in number as the plurality of sub-layers progress from the top layer to the bottom layer, the method comprising: allowing a second process gas to enter the plasma chamber; generating one or more substances from the second process gas using a plasma induced in the plasma chamber; when the one or more substances pass from the plasma chamber into the processing chamber, allowing the first process gas to enter the septum via the gate assembly; and exposing the workpiece to the one or more substances to process the workpiece.

19. The method according to claim 18, wherein, As the one or more substances pass through the plurality of nozzles in the gate assembly, the one or more substances are mixed with the first process gas.

20. The method according to claim 18, wherein, the flow delivery of the first process gas to each of the plurality of nozzles is substantially uniform and / or includes substantially equal flow conductances.

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