Shaped showerhead for edge plasma modulation

Abstract

An exemplary semiconductor processing chamber may include a chamber body. The chamber may include a substrate support disposed within the chamber body. The substrate support may define a substrate support surface. The chamber may include a showerhead supported and positioned above the chamber body. The substrate support and a bottom surface of the showerhead may at least partially define a processing region within the semiconductor processing chamber. The showerhead may define a plurality of apertures extending therethrough. The bottom surface of the showerhead may define an annular groove or ridge positioned directly above at least a portion of the substrate support.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. patent application Ser. No. 17 / 371,575, filed July 9, 2021, entitled "SHAPED SHOWERHEAD FOR EDGE PLASMA MODULATION," the entire contents of which are incorporated herein by reference.

[0002]

[0002] The present technology relates to components and apparatus for semiconductor manufacturing. More specifically, the present technology relates to process chamber distribution components and other semiconductor processing equipment. [Background technology]

[0003]

[0003] Integrated circuits are realized by processes that fabricate intricately patterned layers of material on a substrate surface. Fabricating patterned materials on a substrate requires controlled methods for forming and removing materials. Chamber components often deliver process gases to the substrate for film deposition or material removal. To promote symmetry and uniformity, many chamber components may include regularly patterned features to deliver materials in a manner that may enhance uniformity. However, this may limit recipe adjustment capabilities for on-wafer adjustments.

[0004]

[0004] Thus, there is a need for improved systems and methods that can be used to manufacture high quality devices and structures. Current technology addresses these and other needs. Summary of the Invention

[0005] An exemplary semiconductor processing chamber may include a chamber body. The chamber may include a substrate support disposed within the chamber body. The substrate support may define a substrate support surface. The chamber may include a showerhead supported and positioned above the chamber body. The substrate support and a bottom surface of the showerhead may at least partially define a processing region within the semiconductor processing chamber. The showerhead may define a plurality of apertures extending therethrough. The bottom surface of the showerhead may define an annular groove positioned directly above at least a portion of the substrate support.

[0006] In some embodiments, the substrate support may include a heater pocket projecting upward from an upper surface of the substrate support. The annular groove may have a size and shape corresponding to a size and shape of the heater pocket. The chamber may include an RF mesh embedded within the substrate support. A vertical distance between the RF mesh and a bottom surface of the showerhead may vary over a length of the showerhead. The annular groove may be disposed radially outward of the plurality of apertures. The bottom surface of the showerhead may define an annular ridge projecting downwardly from the bottom surface. The annular groove and the annular ridge may contact one another. The annular groove and the annular ridge may be spaced apart from one another. Inner and outer edges of the annular groove may be tapered. A depth of the groove may be between about 5 mils and 100 mils.

[0007] Some embodiments of the present technology may include a semiconductor processing chamber. The chamber may include a chamber body. The chamber may include a substrate support disposed within the chamber body. The substrate support may define a substrate support surface. The chamber may include a showerhead supported and positioned above the chamber body. The substrate support and a bottom surface of the showerhead may at least partially define a processing region within the semiconductor processing chamber. The showerhead may define a plurality of apertures extending therethrough. The bottom surface of the showerhead may define an annular relief feature.

[0008] In some embodiments, the annular relief feature may include one or both of a groove and a ridge. At least a portion of the annular relief feature may be disposed radially inward of at least one of the plurality of apertures. A subset of the plurality of apertures may be disposed within the annular relief feature. Each of the plurality of apertures may include an upper portion and a lower portion. The lower portion may include a smaller diameter than the upper portion. The lower portion of each of the plurality of apertures in the subset may have the same size as each of the plurality of apertures not included in the subset. A depth or height of the relief feature may be constant across a width of the relief feature. A depth or height of the relief feature may vary across a width of the relief feature. A bottom surface of the showerhead may define an additional annular relief feature.

[0009] Some embodiments of the present technique may include a method of processing a substrate. The method may include flowing a precursor into a processing chamber. The processing chamber may include a showerhead and a substrate support on which the substrate is disposed. A processing volume of the processing chamber may be defined at least in part between the showerhead and the substrate support. The showerhead may define a plurality of apertures therethrough. A bottom surface of the showerhead may define an annular relief feature. The method may include generating a plasma of the precursor in the processing volume of the processing chamber. The method may include depositing material on the substrate.

[0010] In some embodiments, the annular relief feature can include one or both of a groove and a ridge. The substrate support can include an RF mesh. A vertical distance between the RF mesh and a bottom surface of the showerhead can vary over the length of the showerhead.

[0011]

[0011] Such techniques may provide advantages over conventional systems and techniques. For example, embodiments of the present techniques may allow for controlled deposition at the edge region of a substrate. Additionally, the components may maintain plasma generation at the edge region to reduce impact on plasma density and distribution. These and other embodiments, together with their many advantages and features, are described in more detail below in the description and accompanying drawings.

[0012] A further understanding of the nature and advantages of the disclosed techniques may be realized by reference to the remaining portions of the specification and the drawings. [Brief description of the drawings]

[0013] [Figure 1] 1 shows a top plan view of an exemplary processing system in accordance with some embodiments of the present technique. [Figure 2A]

[0014] 1 shows a schematic cross-sectional view of an exemplary processing chamber in accordance with some embodiments of the present technique. [Figure 2B]

[0015] 2B shows a partial schematic cross-sectional view of the showerhead of FIG. 2A. [Figure 2C]

[0016] FIG. 1 shows a partial schematic cross-sectional view of a showerhead in accordance with some embodiments of the present technique. [Figure 2D]

[0017] FIG. 1 shows a partial schematic cross-sectional view of a showerhead in accordance with some embodiments of the present technique. [Diagram 3]

[0018] 1 illustrates steps of an exemplary method of semiconductor processing in accordance with some embodiments of the present technique. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014]

[0019] Some figures are included as schematic diagrams. It should be understood that the drawings are for illustrative purposes and should not be considered to scale unless expressly stated to be to scale. Furthermore, as schematic diagrams, the drawings are provided to aid in understanding and may not include all aspects or information compared to a realistic depiction and may include material that is emphasized for illustrative purposes.

[0015]

[0020] In the accompanying drawings, similar components and / or features may have the same reference numbers. Furthermore, various components of the same type may be distinguished according to the reference numbers, with a letter distinguishing between the similar components. If only a first reference number is used in this specification, the description is applicable to any of the similar components having the same first reference number, regardless of the letter.

[0016]

[0021] A plasma-enhanced deposition process may energize one or more constituent precursors to facilitate film formation on the substrate. Any number of material films may be fabricated to develop semiconductor structures, including conductive and dielectric films, as well as films to facilitate material transport and removal. For example, hard mask films may be formed to facilitate substrate patterning while protecting underlying materials that would otherwise be preserved. In many processing chambers, multiple precursors may be mixed in a gas panel and delivered to the processing region of the chamber where the substrate may be placed. While components of the lid stack may affect the flow distribution into the processing chamber, many other process variables may affect deposition uniformity as well.

[0017]

[0022] As device feature sizes decrease, tolerances across the substrate surface become smaller, and differences in material properties across the film can affect device realization and uniformity. Many chambers contain characteristic process signatures that can cause residual non-uniformity across the substrate. Temperature differences, uniformity of flow patterns, and other aspects of processing can affect the film on the substrate, resulting in differences in film uniformity across the substrate for material created or removed. For example, turbulent deposition gas flow and / or misalignment of the gas box blinds and faceplate apertures can cause deposition gas flow to be non-uniform. Additionally, discontinuities near the wafer edge (such as gaps between the wafer edge and heater pockets) can cause non-uniform gas flow across the wafer, resulting in non-uniform film deposition. In some cases, the blinds may not distribute the flow of precursors to the edge region of the substrate uniformly. Additionally, in some embodiments, the substrate support or heater on which the substrate is positioned can include one or more heating mechanisms to heat the substrate. Differential heat supply or loss between regions of the substrate can affect film deposition. For example, warmer portions of the substrate may deposit thicker or have different film properties than cooler portions. This temperature non-uniformity may result from, for example, temperature variations around the shaft of the substrate support, and may particularly affect the edge region of the substrate.

[0018]

[0023] The present technology overcomes these challenges by incorporating a showerhead that includes one or more relief features, such as grooves and / or ridges. The relief features may vary the size of the inter-electrode gap formed between the showerhead and an RF mesh or other electrode of the substrate support. The inter-electrode gap may be increased to reduce plasma generation (and subsequent film deposition) in a localized region of the processing chamber, and / or may be decreased to increase plasma generation in a localized region. To address the radial non-uniformity issue, these relief features are often annular.

[0019]

[0024] While the remaining disclosure routinely identifies specific deposition processes that utilize the disclosed technology, it will be readily understood that the systems and methods are equally applicable to other deposition and cleaning chambers and processes that may be performed in the described chambers. Thus, the technology should not be considered limited to use with only these specific deposition processes and chambers. This disclosure describes one possible system and chamber that may include lid stack components according to embodiments of the technology before describing additional examples of modifications and adjustments of the system according to embodiments of the technology.

[0020]

[0025] FIG. 1 illustrates a cross-sectional view of an exemplary processing chamber 100 according to some embodiments of the present technique. The diagram may provide an overview of a system incorporating one or more aspects of the present technique and / or capable of performing one or more operations according to embodiments of the present technique. Additional details of the chamber 100 or the method performed may be further described below. Although the chamber 100 may be utilized to form a film layer according to some embodiments of the present technique, it should be understood that the method may be similarly performed in any chamber in which film formation may occur. The processing chamber 100 may include a chamber body 102, a substrate support 104 disposed within the chamber body 102, and a lid assembly 106 connected to the chamber body 102 and enclosing the substrate support 104 within a processing space 120. A substrate 103 may be provided to the processing space 120 through an opening 126. The opening may be conventionally sealed for processing using a slit valve or a door. The substrate 103 may be placed on a surface 105 of the substrate support during processing. The substrate support 104 may be rotatable, as indicated by arrow 145, along an axis 147 on which the shaft 144 of the substrate support 104 may be located. Alternatively, the substrate support 104 may be elevated to rotate as needed during the deposition process.

[0021]

[0026] The plasma profile modulator 111 may be disposed in the process chamber 100 to control plasma distribution across the substrate 103 disposed on the substrate support 104. The plasma profile modulator 111 may include a first electrode 108 that may be disposed adjacent to the chamber body 102 and may separate the chamber body 102 from other components of the lid assembly 106. The first electrode 108 may be part of the lid assembly 106 or may be a separate sidewall electrode. The first electrode 108 may be an annular or ring-shaped member or may be a ring electrode. The first electrode 108 may be a continuous loop around the periphery of the process chamber 100 surrounding the process space 120 or may be discontinuous at selected locations as desired. The first electrode 108 may also be a perforated electrode, such as a perforated ring or mesh electrode, or may be a plate electrode, such as a secondary gas distributor.

[0022]

[0027] One or more isolators 110a, 110b, which may be a dielectric material such as a ceramic or a metal oxide, e.g., aluminum oxide and / or aluminum nitride, may contact the first electrode 108 and electrically and thermally isolate the first electrode 108 from the gas distributor 112 and the chamber body 102. The gas distributor 112 may define an aperture 118 for distributing process precursors into the processing space 120. The gas distributor 112 may be connected to a first power source 142, such as a radio frequency (RF) generator, an RF power source, a DC power source, a pulsed DC power source, a pulsed RF power source, or any other power source that may be connected to a processing chamber. In some embodiments, the first power source 142 may be an RF power source.

[0023]

[0028] The gas distributor 112 may be a conductive or non-conductive gas distributor. The gas distributor 112 may also be formed of conductive and non-conductive components. For example, the faceplate of the gas distributor 112 may be non-conductive while the body of the gas distributor 112 is conductive. The gas distributor 112 may be powered, such as by a first power source 142 as shown in FIG. 1. Alternatively, the gas distributor 112 may be connected to ground in some embodiments.

[0024]

[0029] The first electrode 108 may be connected to a first tuned circuit 128 that may control a ground path of the process chamber 100. The first tuned circuit 128 may include a first electronic sensor 130 and a first electronic controller 134. The first electronic controller 134 may be or may include a variable capacitor or other circuit element. The first tuned circuit 128 may be or may include one or more inductors 132. The first tuned circuit 128 may be any circuit that allows for a variable or controllable impedance under the plasma conditions present in the process space 120 during processing. In some embodiments as shown, the first tuned circuit 128 may include a first circuit leg and a second circuit leg connected in parallel between ground and the first electronic sensor 130. The first circuit leg may include a first inductor 132A. The second circuit leg may include a second inductor 132B connected in series with the first electronic controller 134. The second inductor 132B may be disposed between the first electronic controller 134 and a node connecting both the first and second circuit legs to the first electronic sensor 130. The first electronic sensor 130 may be a voltage or current sensor and may be connected to the first electronic controller 134. This may provide some closed-loop control of the plasma conditions in the process space 120.

[0025]

[0030] The second electrode 122 may be connected to the substrate support 104. The second electrode 122 may be embedded in the substrate support 104 or may be connected to a surface of the substrate support 104. The second electrode 122 may be a plate, a perforated plate, a mesh, a wire screen, or other distributed arrangement of conductive elements. The second electrode 122 may be a tuning electrode and may be connected to a second tuning circuit 136 by a conduit 146, for example a cable with a selected resistance, such as 50 ohms, disposed in a shaft 144 of the substrate support 104. The second tuning circuit 136 may have a second electronic sensor 138 and a second electronic controller 140, which may be a second variable capacitor. The second electronic sensor 138 may be a voltage sensor or a current sensor and may be connected to the second electronic controller 140 to provide further control over the plasma conditions in the process space 120.

[0026]

[0031] A third electrode 124, which may be a bias electrode and / or an electrostatic chuck electrode, may be connected to the substrate support 104. The third electrode may be connected to a second power source 150 through a filter 148, which may be an impedance matching circuit. The second power source 150 may be DC power, pulsed DC power, RF bias power, pulsed RF source or bias power, or a combination of these or other power sources. In some embodiments, the second power source 150 may be RF bias power.

[0027]

[0032] The lid assembly 106 and substrate support 104 of FIG. 1 may be used with any processing chamber for plasma or thermal processing. During operation, the processing chamber 100 may control plasma conditions in the processing space 120 in real time. The substrate 103 may be placed on the substrate support 104. Process gases may be flowed through the lid assembly 106 using the inlet 114 according to any desired flow scheme. The gases may be exhausted from the processing chamber 100 through the outlet 152. Power may be connected to the gas distributor 112 to establish a plasma in the processing space 120. In some embodiments, the substrate may be electrically biased using the third electrode 124.

[0028]

[0033] Upon exciting the plasma in the process space 120, a potential difference may be established between the plasma and the first electrode 108. A potential difference may also be established between the plasma and the second electrode 122. The electronic controllers 134, 140 may then be used to adjust the flow characteristics of the ground path represented by the two tuning circuits 128, 136. Set points may be provided to the first tuning circuit 128 and the second tuning circuit 136 to provide independent control of the deposition rate and center-to-edge plasma density uniformity. In an embodiment where the electronic controllers may both be variable capacitors, the electronic sensors may independently adjust the variable capacitors to maximize the deposition rate and minimize the thickness non-uniformity.

[0029]

[0034] Each of the tuning circuits 128, 136 may have a variable impedance that may be adjusted using the respective electronic controller 134, 140. If the electronic controller 134, 140 is a variable capacitor, the capacitance range of each of the variable capacitors and the inductance of the first inductor 132A and the second inductor 132B may be selected to provide an impedance range. This range may depend on the frequency and voltage characteristics of the plasma, and there may be a minimum value in the capacitance range of each variable capacitor. Thus, when the capacitance of the first electronic controller 134 is at a minimum or maximum, the impedance of the first tuning circuit 128 may be high, resulting in a plasma shape that minimizes aerial or lateral coverage on the substrate support. When the capacitance of the first electronic controller 134 approaches a value that minimizes the impedance of the first tuning circuit 128, the aerial coverage of the plasma may be maximized, effectively covering the entire working area of ​​the substrate support 104. If the capacitance of the first electronic controller 134 deviates from the minimum impedance setting, the plasma shape may shrink from the chamber walls and reduce the aerial coverage of the substrate support. The second electronic controller 140 may have a similar effect of increasing or decreasing the aerial coverage of the plasma on the substrate support as the capacitance of the second electronic controller 140 may be altered.

[0030]

[0035] Electronic sensors 130, 138 may be used to tune the respective circuits 128, 136 in a closed loop. Depending on the type of sensor used, a current or voltage set point is placed on each sensor. The sensors may be equipped with control software that determines the adjustment of each electronic controller 134, 140 to minimize deviation from the set point. As a result, the plasma shape may be selected and dynamically controlled during processing. Although the above discussion is based on the electronic controllers 134, 140 being variable capacitors, it should be understood that any electronic components having adjustable characteristics may be used to provide the tuned circuits 128, 136 with adjustable impedance.

[0031]

[0036] FIG. 2A shows a schematic cross-sectional view of a processing chamber 200 according to some embodiments of the present technique. FIG. 2A may include one or more components described above with respect to FIG. 1 and may provide further details regarding the chamber. The chamber 200 may be used to perform semiconductor processing steps including deposition of a stack of dielectric materials, as previously described. The chamber 200 shows a partial view of a processing region of a semiconductor processing system and may not include all of the components, such as the additional lid stack components described above, that are understood to be incorporated in some embodiments of the chamber 200. The chamber 200 may generally include a chamber body 205 having sidewalls, a bottom wall, and an inner sidewall that define a processing region 210. The processing region 210 may include a substrate support 215 disposed within the processing region 210. The substrate support 215 may include a heater adapted to support a substrate 220 on an exposed surface of the substrate support, such as a body portion. For example, the substrate support 215 may include a pocket 217 that defines an outer boundary of a substrate support surface 219. The pocket 217 projects upwardly from the substrate support 215, and a top surface of the pocket 217 is substantially aligned with a top surface of the substrate 220. For example, the top surface of the pocket 217 may be within about 3% of the height of the top surface of the substrate 220, within about 2% of the height of the top surface of the substrate 220, within about 1% of the height of the top surface of the substrate 220, within about 0.5% of the height of the top surface of the substrate 220, or less. For example, for a substrate 220 having a thickness of 1 mm, the height of the top surface of the pocket 217 may be between about 0.970 mm and 1.030 mm, between about 0.980 mm and 1.020 mm, between about 0.990 mm and 1.010 mm, between about 0.995 mm and 1.005 mm, or about 1 mm. The substrate support 215 may include a heating element 225, such as a resistive heating element, to heat and control the substrate temperature to a desired process temperature. The substrate support 215 may also be heated by a remote heating element, such as a lamp assembly, or any other heating device.

[0032]

[0037] The body of the substrate support 215 may be to a stem 230. The stem 230 may electrically connect the substrate support 215 to a power outlet or power box 235. The power box 235 may include a drive system that controls the elevation and movement of the substrate support 215 within the processing region 210. The stem 230 may also include a power interface for supplying power to the substrate support 215. The power box 235 may also include an interface for power and temperature indicators, such as a thermocouple interface. The precursor distribution assembly 240 may be connected to the top of the chamber body 205 and, optionally, one or more intervening components positioned therebetween. The precursor distribution assembly 240 may deliver reactants and cleaning precursors into the processing region 210. The precursor distribution assembly 240 may include a gas box 245, a shield plate 250, and / or a showerhead 255. The gas box 245 may define or provide access into the processing chamber. The shield plate 250 may be positioned between the gas box 245 and the substrate support 215. The shield plate 250 may include or define a number of apertures through the plate. In some embodiments, the shield plate may be characterized by an increased central conductance. For example, in some embodiments, a subset of apertures proximate to or extending around a central region of the shield plate may be characterized by a larger aperture diameter than apertures radially outside the central region. This may increase the central flow conductance in some embodiments. A radio frequency ("RF") source (not shown) may be coupled to the gas distribution assembly 240 and provide power to the gas distribution assembly 240 to facilitate the generation of a plasma region between the showerhead 255 and the substrate support 215. In some embodiments, the RF source may be coupled to other portions of the chamber body 205, such as the substrate support 215, to facilitate plasma generation. For example, an RF mesh or electrode 270 may be embedded within the body of the substrate support 215 to which RF power may be supplied to facilitate the generation of a plasma within the processing region 210 .

[0033]

[0038] The showerhead 255 may be positioned within the chamber 200 between the shield plate 250 and the substrate support 215, as previously illustrated. The showerhead 255 may be characterized by a first surface 257 and a second surface 259 opposite the first surface 257. In some embodiments, the first surface 257 may face the shield plate 250 and / or the gas box 245. The second surface 259 may be positioned opposite the substrate support 215 within the processing region 210 of the chamber 200. For example, in some embodiments, the second surface 259 of the showerhead 255 and the substrate support 215 may at least partially define the processing region 210. The showerhead 255 may define a number of apertures 260 defined through the showerhead 255 and extending from the first surface 257 through the second surface 259. Each aperture 260 may provide a fluid path through the showerhead 255. The apertures 260 may provide fluid access to a processing region of the chamber. The apertures 260 may have a generally cylindrical cross-section in some embodiments. As shown, each aperture 260 may have an aperture contour that includes a larger upper portion 262 and a smaller lower portion 264, although other aperture contours are possible in various embodiments.

[0034]

[0039] Depending on the size of the showerhead 255 and the size of the apertures 260, the showerhead 255 may define any number of apertures 260 through the plate, for example, about 1,000 apertures or more, about 2,000 apertures or more, about 3,000 apertures or more, about 4,000 apertures or more, about 5,000 apertures or more, about 6,000 apertures or more, or more. As described above, the apertures 260 may be included in a set of rings extending outward from the central axis of the showerhead 255, and may include any number of rings as described above. The rings may be characterized by any number of shapes including circular or elliptical, as well as any other geometric pattern such as rectangular, hexagonal, or any other geometric pattern that may include apertures distributed in multiple rings radially outward. The apertures may be uniformly or staggered and may be spaced about 10 mm or less center-to-center. The apertures can also be spaced apart by about 9 mm or less, about 8 mm or less, about 7 mm or less, about 6 mm or less, about 5 mm or less, about 4 mm or less, about 3 mm or less, or less.

[0035]

[0040] The rings may be characterized by any geometric shape, as described above, and in some embodiments, the apertures may be characterized by a scaling function of the apertures per ring. For example, in some embodiments, the first aperture may extend through the center of the faceplate, such as along the central axis as shown. The first ring of apertures may extend around the central aperture and include any number of apertures, such as between about 4 and about 10 apertures. These apertures may be equally spaced around a geometric shape extending through the center of each aperture. Any number of additional rings of apertures may extend radially outward from the first ring and include a number of apertures that may be a function of the number of apertures in the first ring. For example, the number of apertures in each successive ring may be characterized by the number of apertures in each corresponding ring, as determined by the formula XR, where X is the base number of apertures and R is the corresponding ring number. The base number of apertures is the number of apertures in the first ring, and in some embodiments, may be other numbers when the first ring has an increased number of apertures, as further described below. For example, for an exemplary faceplate having five apertures distributed in the first ring, where 5 may be the base number of apertures, the second ring may be characterized by 10 apertures (5×2), the third ring may be characterized by 15 apertures (5×3), and the twentieth ring may be characterized by 100 apertures (5×20). This may continue for any number of aperture rings, such as up to 50, more than 50, or about 50 rings, as previously described. In some embodiments, each aperture of a plurality of apertures across the faceplate may be characterized by an aperture contour, which may be the same or different in embodiments of the present technology.

[0036]

[0041] As best shown in the partial schematic cross-sectional view of FIG. 2B, the second surface 259 of the showerhead 255 may define one or more annular relief features 275. The relief features 275 may extend 360 degrees or less around the second surface 259. Each relief feature 275 may be in the form of a ridge projecting downwardly from the second surface 259 and / or a groove extending into the second surface 259. For example, as shown, the relief feature 275a is in the form of an annular groove extending around the second surface 259. The cross-section of the relief feature 275 may be constant or may vary along the length of the relief feature 275. The relief feature 275 may have any cross-sectional shape. For example, in some embodiments, the relief feature 275 may have a rectangular cross-sectional shape such that the height (in the case of a ridge) or depth (in the case of a groove) is constant across the width of the relief feature 275. In other embodiments, the cross-section of the relief feature 275 may be tapered and / or contoured such that the height or depth of the relief feature 275 varies across the width of the relief feature 275 .

[0037]

[0042] The inclusion of grooves and / or protrusions / ridges (relief features 275) in the showerhead 255 can change the deposition rate at a given location on the substrate 220. This can be due to a change in the electrical potential between the second surface 259 of the showerhead 255 and the RF mesh 270 when RF power is applied to the showerhead 255 and the RF mesh 270. This electrical potential is dependent on the vertical distance between a portion of the second surface 259 of the showerhead 255 and the RF mesh 270. The presence of the ridge relief feature 275 can decrease the vertical distance between the showerhead 255 and the RF mesh 270, increasing the electrical potential and deposition rate of the portion of the substrate 220 proximate the relief feature 275. The presence of the groove relief feature 275 can increase the vertical distance between the showerhead 255 and the RF mesh 270, decreasing the electrical potential and deposition rate of the portion of the substrate 220 proximate the relief feature 275. In this manner, any number of grooves and / or ridges can be provided in the second surface 259 to vary the vertical distance between the showerhead 255 and the RF mesh 270 along the length of the showerhead 255 to control the deposition rate in one or more regions of the substrate 220.

[0038]

[0043] As shown, the relief feature 275a is in the form of an annular groove having a size and shape that substantially corresponds to the size and shape of the heater pocket 217 (e.g., each dimension of the groove is within about 10% of the corresponding dimension of the heater pocket 217). The inner edge of the groove may have a taper that corresponds to the taper of the inner edge of the heater pocket 217. The outer edge of the groove may be contoured to match the contour of the outer edge of the heater pocket 217. The top surface of the groove may be substantially flat to match the top surface of the heater pocket 217. By locating the groove above the heater pocket 217 (radially outward of the substrate 220), the effect of the lowered electrical potential may be present in the edge region of the substrate 220 (e.g., the outer 85%, 90%, 95%, 97%, 99%, etc. of the radius of the substrate 220).

[0039]

[0044] The height and / or depth of the relief features 275 (and the resulting change in spacing between the showerhead 255 and the RF mesh 270) may correspond to a given change in film thickness. As an example, a spacing change of 1 mil (or other distance) in a given direction may result in a film thickness correction of approximately 210 Å (or other thickness). For example, a 10 mil groove relief feature 275 may reduce the film thickness in a corresponding region of the substrate 220 by approximately 2100 Å, while a 10 mil ridge relief feature 275 may increase the film thickness in a corresponding region of the substrate 220 by approximately 2100 Å. Based on the relationship between the height and / or depth of the relief features 275 and the film thickness, the size, position, and / or shape of each relief feature 275 may be selected to modify the film thickness profile of the substrate 220. For example, one or more ridge relief features can be positioned in areas of the showerhead 255 corresponding to regions of low deposition, while one or more groove relief features can be positioned in areas of the showerhead 255 corresponding to regions of high deposition. The height / depth of the relief features 275 can be about 200 mils or less, about 150 mils or less, about 100 mils or less, about 90 mils or less, about 80 mils or less, about 70 mils or less, about 60 mils or less, about 50 mils or less, about 40 mils or less, about 30 mils or less, about 20 mils or less, about 10 mils or less, about 5 mils or less. In many cases, the depth / height of each relief feature 275 can be between or on the order of about 5 mils and 100 mils.

[0040]

[0045] The height and / or depth of each relief feature 275 across the width of the relief feature 275 may be selected to correspond to a desired variation in film thickness within a given region of the substrate 220. Thus, the size and shape of each relief feature 275 may substantially mimic a peak or valley in the film thickness profile of a known film chemistry using a flat showerhead. This may alter the film deposition rate to effectively reduce the magnitude of v and achieve a more uniform film thickness across the surface of the substrate 220. For example, if the film is too thick in a region of the substrate from about 75% of the radius of the substrate 220 to about 95% of the radius of the substrate 220, a groove relief feature 275 may be formed in the showerhead 255 above and / or slightly outside this region to help reduce the film thickness in this region. Similarly, if the film is too thin in a region of the substrate from about 95% of the radius of the substrate 220 to about 98% of the radius of the substrate 220, a ridge relief feature 275 can be formed in the showerhead 255 above and / or slightly outside this region to help increase the thickness of the film in this region.

[0041]

[0046] The relief feature 275 may be formed radially outward of the apertures 260 of the showerhead 255 and / or may be formed radially inward of an outermost edge of at least one of the apertures 260. For example, as shown, a subset of the apertures 260a is disposed within the relief feature 275a. In such a case, the lower portion 264 of each aperture 260 may be held constant to maintain a uniform flow conductance throughout the showerhead 255. In the case of the apertures 260a, this may result in the length of the upper portion 262a being shortened such that the lower portion 264 of each aperture 260a may be the same length as the lower portion 264 of the apertures 260 that are not included in the subset.

[0042]

[0047] FIG. 2C illustrates a showerhead 255c that may be utilized in the chamber 200. For example, the showerhead 255b may include a ridge relief feature 275c. The relief structure 275c may be sized, positioned, and / or shaped to increase film deposition in one or more known low areas (which may be determined based on deposition processes performed using a different showerhead, such as a flat showerhead). Although shown as having a sharp transition point with varying contours, it will be understood that in some embodiments, the transition point may be rounded and / or have other contours. Such contouring may help prevent flow uniformity issues in the chamber 200. FIG. 2D illustrates a showerhead 255d that may be utilized in the chamber 200. For example, the showerhead 255d may include a relief feature 275d that includes grooves and ridges. The groove portions 280 of the relief structure 275d may be sized, positioned, and / or shaped to reduce film deposition in one or more known high areas. On the other hand, the ridge portion 285 of the relief feature 275d may be sized, positioned, and / or shaped to increase film deposition in one or more known low regions. Although the groove portion 280 and the ridge portion 285 are shown here sharing a boundary and in contact with one another, in some embodiments the groove portion 280 and the ridge portion 285 may be radially spaced apart from one another. Additionally, while the groove portion 280 is shown radially inward of the ridge portion 285, it will be understood that this relative positioning may be reversed in various embodiments. Additionally, it will be understood that any number and / or combination of groove portions and / or ridge portions may be included in some embodiments.

[0043]

[0048] 3 illustrates steps of an exemplary method 300 of semiconductor processing in accordance with some embodiments of the present technique. The method may be performed in a variety of processing chambers, including the processing chamber 200 described above, which may include a showerhead in accordance with embodiments of the present technique, such as showerhead 255. Method 300 may include a number of optional steps that may or may not be particularly relevant to some embodiments of the method in accordance with the present technique.

[0044]

[0049] Method 300 may include a processing method that may include steps for forming a hardmask film or other deposition steps. The method may include optional steps before beginning method 300. Or, the method may include additional steps. For example, method 300 may include steps that are performed in a different order than shown. In some embodiments, method 300 may include flowing one or more precursors into a processing chamber in step 305. For example, the precursors may be flowed into a chamber, such as chamber 200, and may flow through one or more of a gas box, a shield, or a showerhead before delivering the precursors into a processing region of the chamber.

[0045]

[0050] In some embodiments, the showerhead may define one or more annular relief features, such as grooves and / or ridges. The relief features may vary the size of the gap between the electrodes formed between the showerhead and an RF mesh disposed within the substrate support at discrete locations of the showerhead. This change in gap size may cause a change in the deposition rate on the substrate at the location of the relief features. In step 310, a plasma may be generated from the precursors in the processing region, such as by providing RF power to the showerhead to generate the plasma. Material formed in the plasma may be deposited on the substrate in step 315. In some embodiments, the deposited material may be characterized by a thickness at the edge of the substrate that is approximately the same as the thickness in a central region of the substrate. For example, the deposited material may be characterized by a target uniformity of less than 1500 A in thickness proximate to the edge of the substrate.

[0046]

[0051] Additionally, the thickness at the edge of the substrate may be less than or about 9% greater than the thickness adjacent the middle or central region along the radius of the substrate, may be less than or about 8% greater, may be less than or about 7% greater, may be less than or about 6% greater, may be less than or about 5% greater, may be less than or about 4% greater, may be less than or about 3% greater, may be less than or about 2% greater, may be less than or about 1% greater, or may be substantially similar or uniform across the location along the substrate. Uniformity may be improved by utilizing a showerhead having one or more relief features that correspond to regions of high and low thickness of a known film.

[0047]

[0052] In the foregoing description, for purposes of explanation, numerous details have been presented in order to facilitate an understanding of various embodiments of the present technology. However, it will be apparent to one skilled in the art that particular embodiments may be practiced without some of these details or with additional details.

[0048]

[0053] Although several embodiments have been disclosed, those skilled in the art will recognize that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the embodiments. Moreover, in order to avoid unnecessarily obscuring the technology, many well-known processes and elements have not been described. Thus, the above description should not be considered as limiting the scope of the technology.

[0049]

[0054] Where a range of values ​​is provided, it is to be understood that each intervening value between the upper and lower limits of that range is specifically disclosed to the smallest unit of the lower limit, unless the context clearly indicates otherwise. Any smaller ranges between any stated or unstated intervening value in a stated range, as well as any other stated or intervening value in that stated range, are also included. The upper and lower limits of these smaller ranges may be individually included or excluded from the range, and each range in which either, neither, or both limits are included in the smaller ranges is also encompassed within the scope of the technology, subject to any specifically excluded limits in the stated range. Where one or both limits are included in a stated range, ranges excluding either or both of those included limits are also included.

[0050]

[0055] As used in this specification and claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, a reference to "a heater" includes a plurality of such heaters, a reference to "the protrusion" includes a reference to one or more protrusions and equivalents thereof known to those skilled in the art, and so forth.

[0051]

[0056] Additionally, the terms "comprise(s)", "comprising", "contain(s)", "containing", "include(s)", and "including", when used in this specification and claims, are intended to specify the presence of stated features, integers, components, or steps, but do not exclude the presence or addition of one or more other features, integers, components, steps, operations, or groups.

Claims

1. 1. A semiconductor processing chamber comprising: A chamber body; a substrate support disposed within the chamber body, the substrate support defining a substrate support surface; a showerhead supported and positioned on an upper portion of the chamber body; Equipped with the substrate support and a bottom surface of the showerhead at least partially define a processing volume within the semiconductor processing chamber; the showerhead defines a plurality of apertures extending therethrough; the bottom surface of the showerhead defines an annular groove positioned directly above at least a portion of the substrate support; The semiconductor processing chamber, wherein the annular groove is disposed radially outward of the plurality of apertures.

2. the substrate support comprising a heater pocket projecting upwardly from a top surface of the substrate support; 2. The semiconductor processing chamber of claim 1, wherein said annular groove has a size and shape corresponding to a size and shape of said heater pocket.

3. An RF mesh embedded within the substrate support.

10. The semiconductor processing chamber of claim 1 , further comprising: a vertical distance between said RF mesh and said bottom surface of said showerhead varying.

4. 10. The semiconductor processing chamber of claim 1, wherein said bottom surface of said showerhead defines an annular ridge projecting downwardly from said bottom surface.

5. The semiconductor processing chamber of claim 4 , wherein said annular groove and said annular ridge contact each other.

6. The semiconductor processing chamber of claim 4 , wherein said annular groove and said annular ridge are spaced apart from one another.

7. 2. The semiconductor processing chamber of claim 1, wherein the inner and outer edges of the annular groove are tapered.

8. 10. The semiconductor processing chamber of claim 1, wherein the groove has a depth between 5 and 100 mils.

9. 1. A semiconductor processing chamber comprising: A chamber body; a substrate support disposed within the chamber body, the substrate support defining a substrate support surface; a showerhead supported and positioned on an upper portion of the chamber body; Equipped with the substrate support and a bottom surface of the showerhead at least partially define a processing volume within the semiconductor processing chamber; the showerhead defines a plurality of apertures extending therethrough; the bottom surface of the showerhead defines an annular relief feature; The semiconductor processing chamber, wherein the annular relief feature is disposed radially outward of the plurality of apertures.

10. The semiconductor processing chamber of claim 9 , wherein the annular relief feature comprises one or both of a groove and a ridge.

11. The semiconductor processing chamber of claim 9 , wherein at least a portion of the annular relief feature is disposed radially inward of at least one of the plurality of apertures.

12. The semiconductor processing chamber of claim 11 , wherein a subset of the plurality of apertures is disposed within the annular relief feature.

13. each of the plurality of apertures includes an upper portion and a lower portion, the lower portion having a smaller diameter than the upper portion; 13. The semiconductor processing chamber of claim 12, wherein a lower portion of each of the plurality of apertures in the subset has the same size as each of the plurality of apertures not included in the subset.

14. 10. The semiconductor processing chamber of claim 9, wherein the depth or height of the relief feature is constant across a width of the relief feature.

15. 10. The semiconductor processing chamber of claim 9, wherein the depth or height of the relief feature varies across a width of the relief feature.

16. 10. The semiconductor processing chamber of claim 9, wherein the bottom surface of the showerhead defines an additional annular relief feature.

17. 1. A method for processing a substrate, comprising: Flowing a precursor into a processing chamber, the processing chamber comprising a showerhead and a substrate support on which a substrate is disposed; a processing volume of the processing chamber is defined at least in part between the showerhead and the substrate support; the showerhead defines a plurality of apertures extending therethrough; flowing a precursor into the showerhead, the bottom surface of the showerhead defining an annular relief feature; generating a plasma of the precursor in a processing region of the processing chamber; depositing a material onto the substrate; Including, The method, wherein the annular relief feature is disposed radially outward of the plurality of apertures.

18. 20. The method of processing a substrate according to claim 17, wherein the annular relief feature comprises one or both of a groove and a ridge.

19. the substrate support includes an RF mesh; 20. The method of processing a substrate as recited in claim 17, wherein the vertical distance between the RF mesh and the bottom surface of the showerhead varies.

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