Processing chamber with improved processing at the edges of the substrate
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- APPLIED MATERIALS INC
- Filing Date
- 2023-04-05
- Publication Date
- 2026-05-19
AI Technical Summary
Existing semiconductor processing chambers fail to uniformly distribute reactive species across the entire substrate surface, leading to under-processing and contamination at the edges, resulting in non-uniform processing profiles and reduced etching or deposition rates.
A processing chamber design featuring a showerhead assembly with varying opening densities, a flow divider to direct gas flow to the edges, and a focus ring to enhance reactive species distribution, ensuring efficient processing at the substrate edges.
Improves processing efficiency and uniformity at the substrate edges by effectively delivering reactive species, reducing contamination and achieving consistent processing profiles across the entire substrate.
Smart Images
Figure 0007862340000001 
Figure 0007862340000002 
Figure 0007862340000003
Abstract
Description
Technical Field
[0001]
[0001] Embodiments of the present disclosure generally relate to methods and apparatuses for manufacturing devices on a semiconductor substrate. In particular, embodiments of the present disclosure provide methods and apparatuses for improving substrate edge processing performance for semiconductor applications.
Background Art
[0002]
[0002] During the manufacture of semiconductor devices, the substrate is typically processed within a processing chamber, and deposition, etching, and heat treatment can be performed on the substrate.
[0003]
[0003] As the dimensions of the components of integrated circuits become smaller (e.g., in sub-micron dimensions), the importance of reducing contaminants has increased. This is because contaminants can cause the formation of defects during the semiconductor manufacturing process. For example, in an etching process, by-products such as polymers that can be generated during the etching process can be a source of particulate matter that contaminates the integrated circuits and structures formed on the substrate. In some implementations, such by-products are often found at specific locations on the substrate, such as the edges of the substrate.
[0004]
[0004] A semiconductor processing chamber generally includes a chamber body that defines an internal space for processing a substrate. A substrate support is usually placed within the internal space to support the substrate during processing. During the process, reactive species generated during the process may not be uniformly distributed across the entire substrate surface. For example, reactive species may not reach or be able to spread to the edges of the substrate during the process, resulting in under-processed edges or undesirable contamination, accumulation, or by-products. Under-processing at the edges of the substrate can result in lower etching or deposition rates at the edges of the substrate compared to the center of the substrate. Furthermore, in some cases, reactive species may be able to easily reach the center of the substrate for processing but may not have enough momentum or energy to move to the edges of the substrate for processing. As a result, different processing profiles may be obtained at the center and edges of the substrate, resulting in the formation of undesirable non-uniform profiles across the entire substrate.
[0005]
[0005] Therefore, a processing chamber is needed that has improved processing performance for the edges of the substrate inside the processing chamber. [Overview of the project]
[0006]
[0006] Embodiments of the present disclosure generally provide apparatus and methods for processing substrates. More specifically, embodiments of the present disclosure provide a processing chamber having improved processing efficiency at the edges of a substrate placed in the processing chamber. In one embodiment, the processing chamber comprises a chamber body defining an internal processing area within the processing chamber; a showerhead assembly disposed within the processing chamber, the showerhead assembly having a plurality of areas having a higher pore density in the edge area than in the central area of the showerhead assembly; a substrate support assembly disposed within the internal processing area of the processing chamber; and a focus ring disposed on the edge of the substrate support assembly and surrounding the substrate support assembly, the focus ring having a step having a side wall height substantially the same as the lower width.
[0007]
[0007] In another embodiment, a shower head plate having a plurality of openings formed inside, wherein the shower head plate has a plurality of regions having different opening densities, and the region located within the central region of the shower head plate has a larger open area than the region located within the edge region.
[0008]
[0008] In yet another embodiment, a method for improving processing efficiency at the edges of the substrate includes diverting a gas flow from a remote plasma source to the edge area of the showerhead assembly via a flow diverter, and directing the gas flow to the edges of the substrate through openings in the edge area of the showerhead assembly.
[0009]
[0009] In order to provide a detailed understanding of the features of the present disclosure described above, the present disclosure, which has been briefly summarized above, will be described in more detail with reference to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings show only typical embodiments of the present disclosure, and therefore the present disclosure may allow for other equally valid embodiments, and should not be considered to limit the scope of the present disclosure. [Brief explanation of the drawing]
[0010] [Figure 1]
[0010] This is a schematic cross-sectional view of a processing chamber according to one embodiment of the present disclosure. [Figure 2]
[0011] This is a schematic perspective view of a focus ring used in a processing chamber according to one embodiment of the present disclosure. [Figure 3A]
[0012] This is a portion of a cross-sectional view of the focus ring shown in Figure 2 according to one embodiment of the present disclosure. [Figure 3B] This is a portion of a cross-sectional view of the focus ring shown in Figure 2 according to one embodiment of the present disclosure. [Figure 4]
[0013] Figure 1 is a bottom view of a shower head assembly according to one embodiment of the present disclosure. [Figure 5]
[0014] This is a perspective view of a flow divider used in a showerhead assembly according to one embodiment of the present disclosure, as shown in Figure 1. [Modes for carrying out the invention]
[0011]
[0015] To facilitate understanding, the same reference numerals were used where possible to indicate identical elements common to the drawings. Even without specific descriptions, it is assumed that elements disclosed in one embodiment can be usefully utilized in another embodiment.
[0012]
[0016] Embodiments of the present disclosure provide a processing chamber and method for improving processing efficiency at the edges of a substrate placed within the processing chamber. More specifically, embodiments of the present disclosure relate to a processing chamber having specific embodiments of a showerhead assembly, a flow divider, and a focus ring for improving processing efficiency at the edges of a substrate placed within the processing chamber. In one embodiment, a showerhead assembly that improves gas flow at the edges of the showerhead assembly can be used to help deliver a relatively large amount of reactive species to the edges of the substrate. A flow divider can also be used to restrict and direct the flow path of reactive species to the edges of the substrate. Furthermore, a focus ring having a desired profile can also be used to provide a reactive channel extending to the edges of the substrate.
[0013]
[0017] Figure 1 is a schematic cross-sectional view of a processing chamber 100 according to one embodiment of the present disclosure. The processing chamber 100 includes an internal processing space 120 for transferring and processing a substrate 104.
[0014]
[0018] The processing chamber 100 includes a chamber body 121. In one embodiment, the chamber body 121 defines an internal processing space 120. The processing chamber 100 comprises a shower head assembly 189 and a substrate support assembly 153 positioned within the internal processing space 120. The shower head assembly 189 is positioned on top of the substrate support assembly 153. The substrate support assembly 153 supports the substrate 104 within the internal processing space 120 in the processing chamber 100.
[0015]
[0019] A lid liner 127 is positioned on the side wall 103 of the chamber body 121 to provide a profile sealing between the side wall 103 and the ceiling 128 of the processing chamber 100. The lid liner 127 has a lip that holds the shower head assembly 189 and the ceiling 128. In one embodiment, the ceiling 128 may be a source adapter plate 126. The source adapter plate 126 has a central opening 128a that matches the central opening 189a of the shower head assembly 189. A remote plasma source 130 is in fluid communication with the internal processing space 120 through a quartz insert 131 and the shower head assembly 189.
[0016]
[0020] The showerhead assembly 189 comprises a lower plate 199 having a plurality of openings 188 formed inside it. The lower plate 199 of the showerhead assembly 189 has a plurality of areas 190, 191, 192, and 193 with different densities and numbers of openings 188 formed inside it. Further details regarding the distribution and profile of the openings within the showerhead assembly 189 will be described below with reference to Figure 4.
[0017]
[0021] A flow divider 170 is positioned above the lower plate 199 through the central opening 189a of the showerhead assembly 189. The flow divider 170 diverts the gas flow from the remote plasma source 130 to various locations on the lower plate 199 so that the gas flow can be further directed to various locations on the substrate 104 through the opening 188. The flow divider 170 may have a predetermined geometric profile to allow gas flow in a particular direction. As a result, a gas flow in one direction may have a larger flux than a gas flow in another direction. In the embodiment shown in Figure 1, the flow divider 170 diverts the gas flow from the remote plasma source 130 so that it flows radially outward to the outer areas 192, 193 (e.g., edge areas) rather than the inner areas 190, 191 (e.g., central area) of the showerhead assembly 189. Therefore, in embodiments where the edges of the substrate 104 require improved treatment with a higher flux density of reactive species, the flow divider 170 can be used to direct the flow of reactive species to a desired location on the edges of the substrate 104. The details of the configuration of the flow divider 170 will be further explained below with reference to Figure 5.
[0018]
[0022] The remote plasma source 130 is typically connected to one or more gas panels. In one embodiment, the remote plasma source 130 is connected to a first gas panel 101 configured to provide a processing gas for a mitigation process to remove residual material after etching, and a second gas panel 102 configured to provide a processing gas for an ashing process to remove photoresist or any other residue from the substrate 104.
[0019]
[0023] The processing chamber 100 further includes a substrate support assembly 153 positioned within the internal processing space 120 to support the substrate 104. A focus ring 160 may be positioned on the outer edge of the substrate support assembly 153. The focus ring 160 functions to hold the substrate 104 and to correct the processing speed around the edge area of the substrate 104 during processing. A base support 180 is inserted between the focus ring 160 and the surface of the substrate support assembly 153 to help support the focus ring 160 in proper position. The focus ring 160 is positioned and formed to define a step 168 at the corner of the focus ring 160. The defined step 168 can efficiently allow plasma species or reactive species to flow toward the substrate bevel or the substrate edge to assist the reaction of reactive species toward the substrate edge or the substrate bevel. Further details of the focus ring 160 will be described below with reference to Figures 3A and 3B.
[0020]
[0024] The substrate support assembly 153 is placed inside the chamber body 121 to support the substrate 104 during processing. The substrate support assembly 153 may be a conventional mechanical chuck, or an electrostatic chuck in which at least a portion of the substrate support assembly 153 is conductive and can act as a process bias cathode by an RF bias power supply 171 coupled to the substrate support assembly 153. The substrate placed on the substrate support assembly 153 can be raised and lowered by wafer lift pins (not shown) to facilitate the transfer of the substrate to and from the substrate support assembly 153.
[0021]
[0025] Controller 172 includes a central processing unit (CPU) 174, a memory 176, and a support circuit 178 that controls process sequences and is used to adjust the gas flow within processing chamber 100 and the plasma processes performed therein. CPU 174 may be any form of general-purpose computer processor that can be used in industrial settings. Software routines, such as those for processes implemented within processing chamber 100, may be stored within memory 176, such as random access memory, read-only memory, floppy, or hard disk drives, or other forms of digital storage. Support circuit 178 is coupled to CPU 174 and can include a cache, clock circuit, input / output system, power supply, and the like. Bidirectional communication between controller 172 and the various components of processing chamber 100 is processed via a number of signal cables collectively referred to as a signal bus. A portion of which is shown in FIG. 1.
[0022]
[0026] FIG. 2 is a schematic perspective view of an example of a focus ring 160 used within processing chamber 100 according to one embodiment of the present disclosure. Focus ring 160 may be in the form of a donut shape having a central opening 205. Central opening 205 has a diameter 210 sized such that a substrate 104 having a desired diameter range (e.g., 200 mm, 300 mm, or 450 mm, etc.) can be accommodated therein with the substrate support assembly 153 disposed therearound. In one example, diameter 210 may be between about 11 inches and about 13 inches.
[0023]
[0027] In one embodiment, the focus ring 160 has an upper body 164 connected to the lower body 162. The upper body 164 has an upper outer wall 167 and an upper inner wall 165. The upper inner wall 165 defines the diameter 210 of the opening 205. The upper outer wall 167 defines the outer periphery of the focus ring 160. The upper outer wall 167 and the upper inner wall 165 are connected by the upper surface 163 of the upper body 164. The upper surface 163 of the upper body 164 defines a plane parallel to the upper surface of the substrate support assembly 153. The lower body 162 is connected to the upper body 164 to form a single body of the focus ring 160. In some embodiments, the lower body 162 and the upper body 164 can be separated and reassembled as needed, such as when installed in the processing chamber 100 so as to surround the substrate support assembly 153.
[0024]
[0028] The lower body 162 also includes a lower outer wall 306 and a lower inner wall 301. The lower outer wall 306 is formed inwardly from the upper outer wall 167 of the focus ring 160. In contrast, the lower inner wall 301 is formed to extend outwardly from the upper inner wall 165 toward the central opening 205 of the focus ring 160. In one embodiment, the focus ring 160 can be manufactured from a material including a dielectric material such as aluminum nitride, aluminum oxide, aluminum oxynitride, etc.
[0025]
[0029] Figure 3A shows a cross-sectional view of the focus ring 160 of Figure 2 along the cross-sectional line A–A'. The step 168 of the focus ring 160 is defined between the upper inner wall 165 and the exposed surface 315 of the lower body 162. The upper body 164 may have a thickness 302 between approximately 0.25 inches and approximately 0.5 inches, defining the height of the step 168. In the embodiment shown in Figure 3A, the upper inner wall 165 may have a substantially vertical surface perpendicular to the exposed surface 315 of the lower body 162. The upper inner wall 165 also defines the side wall of the step 168. The lower body 162 has a thickness 310 (e.g., height) between approximately 0.25 mm and approximately 1 inch, allowing for proper fitting of the focus ring 160 to the base support 180 positioned on the substrate support assembly 153. The thickness 310 of the lower body 162 is greater than the thickness 302 of the upper body 164. In one embodiment, the thickness 310 of the lower body 162 is between approximately 20% and approximately 50% greater than the thickness 302 of the upper body 164.
[0026]
[0030] The lower body 162 also has a width 312 ranging from approximately 1 inch to approximately 5 inches. The exposed surface 315 of the lower body 162, exposed by the upper body 164, has a width 169 ranging from approximately 0.5 inches to approximately 5 inches, which also defines the width of the step 168. The exposed surface 315 is also the bottom surface of the step 168. In one embodiment, the thickness 302 (which is also the sidewall height of the step 168) is substantially the same as or equal to the width 169 of the exposed surface 315 (which is also the bottom surface of the step 168). It should be noted that the dimensions of the step 168 formed within the focus ring 160 may be predetermined to allow sufficient space to facilitate the flow of reactive species from the internal processing space 120 to the nearby substrate edge. The step 168 may help to hold reactive species for a longer time, allowing for processing of the substrate edge or bevel of the substrate. The lower inner wall 301 is configured to contact or be close to the edge of the substrate 104 to help hold the substrate 104 in a desired position. The exposed surface 315 of the lower body 162 is substantially parallel to the upper surface 163 of the upper body 164. The upper body 164 has an overall width 314 between approximately 1 inch and approximately 5 inches.
[0027]
[0031] Figure 3B depicts another embodiment of a focus ring 300 that may be used to surround a substrate support assembly 153 within a processing chamber 100. Similar to the focus ring 160 depicted in Figure 3A, the focus ring 300 also has an upper body 354 and a lower body 352. A step 360 is formed between the upper inner wall 356 of the upper body 354 and the exposed surface 358 from the lower body 352. Although the focus ring 300 is structurally similar to the focus ring 160 in Figure 3A, the upper inner wall 356 of the focus ring 300 may be constructed differently. Unlike the substantially vertical upper inner wall 165 from the focus ring 160, the upper inner wall 356 of the focus ring 300 has a bevel 362 with an angle θ with respect to the exposed surface 358 from the lower body 352. The angle θ is between approximately 20 degrees and approximately 110 degrees. The bevel 362 of the upper inner wall 356 is thought to help hold a larger number of reactive species within the step 360 to support reactions at the edges or bevels of the substrate. The dimensions of the upper body 354 and lower body 352 of the focus ring 300 may be the same as or identical to those of the focus ring 160 depicted in Figure 3A.
[0028]
[0032] Figure 4 shows a bottom view of the shower head assembly 189 of Figure 1. The shower head assembly 189 has several regions 190, 191, 192, and 193 with different numbers and densities of openings 188 formed inside it. At least two regions have a different number of openings 188 formed within the shower head assembly 189. Furthermore, in some embodiments, the different regions may be made from different materials as needed. The regions 190, 191, 192, and 193 may be formed in different geometric shapes or patterns, such as being arranged in a concentric ring shape, a grid or slice pattern, or other combinations of different geometric shapes as needed. In some embodiments where an improved gas flow of reactive species is desired at the edge of the substrate 104, the edge regions 192 and 193 facing the edge of the substrate 104 may be configured to have a higher density of openings. The density of regions 190, 191, 192, and 193 can be gradually reduced (e.g., gradient) to control the amount of reactive species supplied to central regions 190 and 191 compared to edge regions 192 and 193. In some embodiments, central regions 190 and 191 may not have openings. Thus, the open area gradually increases from the edge region 193 to the central region 190 (e.g., from region 193, sequentially to region 192, region 191, and finally to region 190). Thus, the number and density of openings are gradually reduced as needed. In one embodiment, the opening density decreases or increases by about 2% to about 20% relative to each adjacent region. Openings within each region may be aligned in the horizontal plane. Openings formed in different regions may or may not be aligned horizontally.
[0029]
[0033] Figure 5 illustrates a flow divider 170 that may be positioned within the processing chamber 100 above the lower plate 199 of the showerhead assembly 189. The flow divider 170 may be positioned in direct contact with the lower plate 199, or slightly above the lower plate 199 at a desired distance from it. The flow divider 170 has a conical shape. The flow divider 170 has a taper 502 toward the center and has, for example, one lower end (or base) 504 in the plane of the lower plate 199 that is wider than the far end or distal end 506, i.e., the first dimension 508 is greater than the second dimension 510. It should be noted that the shape or dimensions of the flow divider 170, as well as the shape, position, and dimensions of the flow divider 170, may be modified according to the needs of a particular design and application, taking into account the chamber dimensions, pumping configuration, gas flow velocity, improved flow shape, etc. Apart from achieving a specific desired processing speed or uniformity, the design parameters are selected to provide a process with a relatively wide margin.
[0030]
[0034] In one embodiment, the shape of the lower end 504 is circular. The first dimension 508 is between approximately 1.5 inches and approximately 4 inches, and the second dimension 510 is between approximately 0.05 inches and approximately 0.5 inches. In some embodiments, the first dimension 508 is between approximately 20 times and approximately 40 times the second dimension 510. The shunter 170 also has a height 512 (from the lower end 504 to the distal end 506) between approximately 0.25 inches and approximately 1.5 inches. The shunter 170 may be made from a material including an aluminum-containing material.
[0031]
[0035] In one embodiment, the flow divider 170 may be a solid body that does not allow a gas flow to pass through it (for example, the tapered 502 has a solid body formed from the lower end 504 to the distal end 506). In another embodiment, the flow divider 170 is hollow from the lower end 504 to the distal end 506 (for example, the tapered 502 is a hollow body with a cavity formed from the lower end 504 to the distal end 506), allowing open fluid communication from the distal end 506 to the lower end 504 when a gas or reactant flows through it. In embodiments where the flow divider 170 is hollow, a gas or reactant from a remote plasma source 130 may be directed towards the central area 190 where the hollow is located.
[0032]
[0036] In one embodiment, gas flows from gas panels 102, 101 are directed vertically downward through a channel 155 (shown in Figure 1) connected to a flow divider 170. The gas flow is then bent or redirected by the flow divider 170 primarily to openings 188 in the edge regions 193, 192. Thus, the gas flow does not flow to the central regions 190, 191, which have fewer or no openings. By adjusting the position, geometric shape, and dimensions of the flow divider 170, the spatial or lateral distribution of ions, neutral species, and reactive species passing through the flow divider 170 can be controlled, thereby enabling optimization of the substrate edge processing rate profile. In the embodiment depicted in Figure 1, the flow divider 170 is centered on or above the lower plate 199 of the showerhead assembly 189, but it may be positioned elsewhere or provided in different shapes and dimensions to establish a desired flow pattern suitable for the needs of other applications. During processing, the process gas is ignited and generated as a remote plasma source from a remote plasma source 130 supplied to the internal processing space 120.
[0033]
[0037] Although embodiments of the present disclosure have been described above in the context of processing chamber applications, embodiments of the present disclosure can be applied to any process chamber, such as load lock chambers or transfer chambers. In particular, embodiments of the present disclosure are useful in applications where it is desirable to improve the processing speed at the edges of the substrate and thereby improve the processing efficiency at the edges of the substrate.
[0034]
[0038] While the above description applies to embodiments of the present disclosure, other embodiments and further embodiments of the present disclosure may be devised without departing from the basic scope of the present disclosure, and the scope of the present disclosure is defined by the following claims.
Claims
1. A processing chamber, A chamber body that defines the internal processing area within the processing chamber, A shower head assembly provided within the processing chamber, having at least four regions having different opening densities, wherein the at least four regions include at least a first region located in the central region and the innermost region, and a second region located in the edge region, the first region having no openings, and each of the at least four regions other than the first region having an opening density greater than that of the region immediately adjacent to the region closer to the central region, A focus ring is positioned on the edge of a substrate support assembly and surrounds the substrate support assembly, the focus ring having an upper part and a lower part, the lower part being connected to the upper part and integrally forming the body of the focus ring, the step of the focus ring being defined between the upper inner wall of the upper part and the upper surface of the lower part, the upper surface of the lower part being coplanar with the bottom surface of the upper part, and when a substrate is placed in the substrate support assembly, the inner circumference of the lower part being configured to surround the substrate, and the upper inner wall having the same height as the length of the upper surface, A processing chamber equipped with the following:
2. The processing chamber according to claim 1, further comprising a flow divider positioned above the shower head assembly.
3. The processing chamber according to claim 2, wherein the current shunt is in communication with a remote plasma source.
4. The processing chamber according to claim 2, wherein the flow divider has a base that is tapered upward to the distal end.
5. The processing chamber according to claim 4, wherein the base has a first dimension, the distal end has a second dimension, and the first dimension is greater than the second dimension.
6. The processing chamber according to claim 5, wherein the first dimension is between 20 and 40 times the second dimension.
7. The processing chamber according to claim 5, wherein the base is circular.
8. The processing chamber according to claim 1, wherein the central region of the shower head assembly does not have an opening.
9. The processing chamber according to claim 1, wherein the step has an inclined side wall.
10. The processing chamber according to claim 1, wherein the lower portion has a first thickness greater than the second thickness of the upper portion.