Process chamber with substrate edge enhancement processing

Abstract

Embodiments of the present disclosure generally provide apparatuses and methods for processing a substrate. More specifically, embodiments of the present disclosure provide a processing chamber having enhanced processing efficiency for the edge of a substrate disposed in the processing chamber. In one embodiment, the processing chamber includes a chamber body defining an inner processing region in the processing chamber, a showerhead assembly disposed in the processing chamber, wherein the showerhead assembly has a plurality of zones, wherein the density of apertures at an edge zone of the showerhead assembly is higher than the density of apertures at a center zone of the showerhead assembly, a substrate support assembly disposed in the inner processing region of the processing chamber, and a concentration ring disposed on an edge of the substrate support assembly and surrounding the substrate support assembly, wherein the concentration ring has a step having a sidewall height substantially similar to a bottom width.

Description

Background Technology Technical Field

[0002] The embodiments of this disclosure generally relate to methods and apparatus for fabricating devices on semiconductor substrates. More specifically, embodiments of this disclosure provide methods and apparatus for enhancing substrate edge processing performance for semiconductor applications. Related technical specifications

[0003] During the manufacturing of semiconductor devices, substrates are typically processed in processing chambers, where deposition, etching, and heat treatment can be performed on the substrates.

[0004] As the size of integrated circuit components shrinks (e.g., to submicron dimensions), the importance of reducing the presence of contaminants has increased, as such contaminants can lead to the formation of defects during semiconductor manufacturing processes. For example, in etching processes, byproducts (such as polymers that can be generated during etching) can become a source of particulate matter, thereby contaminating the integrated circuits and structures formed on the substrate. In some practices, such byproducts are typically found at certain locations on the substrate, such as at the edges of the substrate.

[0005] Semiconductor processing chambers typically include a chamber body that defines an internal volume for processing a substrate. Substrate supports are typically disposed within the internal volume to support the substrate during processing. During the process, reactive materials generated during the process may not be uniformly distributed across the substrate surface. For example, reactive materials may not reach or extend to the edges of the substrate during processing, resulting in inadequate processing at the substrate edges or undesirable contamination, buildup, or byproducts. Inadequate processing at the substrate edges can lead to lower etch or deposition rates at the substrate edges relative to the substrate center. Furthermore, in some examples, reactive materials may easily reach the substrate center for processing but may not possess sufficient momentum or energy to travel to the substrate edges for processing. Therefore, different processing profiles may be obtained at the center and edges of the substrate, resulting in an undesirable, non-uniform profile across the substrate.

[0006] Therefore, there is a need for processing chambers that provide enhanced processing performance for the substrate edges within the processing chamber. Summary of the Invention

[0007] The embodiments of this disclosure generally provide apparatus and methods for processing substrates. More specifically, embodiments of this disclosure provide a processing chamber that provides enhanced processing efficiency for the edges of a substrate disposed within the processing chamber. In one embodiment, the processing chamber includes: a chamber body defining an internal processing region within the processing chamber; a nozzle assembly disposed within the processing chamber, wherein the nozzle assembly has a plurality of zones, wherein the pore density at the edge zones of the nozzle assembly is higher than the pore density at the central zone of the nozzle assembly; a substrate support assembly disposed in the internal processing region of the processing chamber; and a focus ring disposed on the edge of the substrate support assembly and surrounding the substrate support assembly, wherein the focus ring has a step having a sidewall height substantially similar to the bottom width.

[0008] In another embodiment, a nozzle plate has a plurality of pores formed therein, wherein the nozzle plate has a plurality of zones with different pore densities, wherein a zone located in the central region of the nozzle plate has a larger opening area than a zone located in the edge region of the nozzle plate.

[0009] In yet another embodiment, a method for enhancing substrate edge processing efficiency includes: diverting airflow from a remote plasma source to the edge region of a nozzle assembly via a splitter; and guiding the airflow through apertures in the edge region of the nozzle assembly toward the edge of the substrate. Attached Figure Description

[0010] To gain a more detailed understanding of the features of this disclosure described above, a more specific description of the disclosure, which has been briefly summarized above, can be obtained by referring to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only typical embodiments of this disclosure and should therefore not be considered as limiting its scope, as this disclosure allows for other equivalent and effective embodiments.

[0011] Figure 1 This is a schematic cross-sectional view of a processing chamber according to an embodiment of the present disclosure.

[0012] Figure 2 This is a schematic perspective view of a central ring used in a processing chamber according to an embodiment of the present disclosure.

[0013] Figures 3A to 3B According to one embodiment of this disclosure Figure 2 A portion of the cross-sectional view of the concentrated ring.

[0014] Figure 4 According to one embodiment of this disclosure Figure 1 A bottom view of the nozzle assembly.

[0015] Figure 5 According to one embodiment of this disclosure Figure 1 A perspective view of the splitter used in the nozzle assembly.

[0016] To facilitate understanding, the same reference numerals have been used as much as possible to represent the same elements common in the figures. It is contemplated that elements disclosed in one embodiment may be advantageously used in other embodiments without special description. Detailed Implementation

[0017] Embodiments of this disclosure provide processing chambers and methods for enhancing processing efficiency at the edge portions of a substrate disposed within a processing chamber. More specifically, embodiments of this disclosure relate to a processing chamber having certain embodiments of a nozzle assembly, a flow divider, and a concentrating ring for enhancing processing efficiency at the edge of a substrate disposed within the processing chamber. In one embodiment, a nozzle assembly having enhanced airflow at the edge of the nozzle assembly can be used to assist in carrying a relatively high amount of reactive material to the edge of the substrate. The flow divider can also be used to restrict and guide the flow path of the reactive material to the edge of the substrate. Furthermore, a concentrating ring having a desired profile is also used to provide an extended reactive flow path to the edge of the substrate.

[0018] Figure 1 This is a schematic cross-sectional view of a processing chamber 100 according to an embodiment of the present disclosure. The processing chamber 100 includes an internal processing volume 120 for transferring and processing a substrate 104.

[0019] The processing chamber 100 includes a chamber body 121. In one embodiment, the chamber body 121 defines an internal processing volume 120. The processing chamber 100 includes a nozzle assembly 189 and a substrate support assembly 153 disposed within the internal processing volume 120. The nozzle assembly 189 is disposed on the substrate support assembly 153. The substrate support assembly 153 supports a substrate 104 within the internal processing volume 120 of the processing chamber 100.

[0020] A cover gasket 127 is disposed over the sidewall 103 of the chamber body 121 to provide a contour seal between the sidewall 103 of the processing chamber 100 and the ceiling 128. The cover gasket 127 has a lip that retains the nozzle assembly 189 and the ceiling 128. In one example, 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 nozzle assembly 189. A remote plasma source 130 is in fluid communication with the internal processing volume 120 via a quartz insert 131 and the nozzle assembly 189.

[0021] The nozzle assembly 189 includes a lower plate 199 having a plurality of pores 188 formed therein. The lower plate 199 of the nozzle assembly 189 has a plurality of regions 190, 191, 192, and 193, each region having pores 188 of different densities and numbers formed therein. Details regarding the pore distribution and profile in the nozzle assembly 189 will be referenced below. Figure 4 Further discussion.

[0022] The splitter 170 is positioned through the central opening 189a of the nozzle assembly 189 above the lower plate 199. The splitter 170 diverts the gas flow from the remote plasma source 130 to different locations on the lower plate 199, allowing the gas flow to be further guided through the orifice 188 to different locations on the substrate 104. The splitter 170 may have a predetermined geometric profile to allow the gas flow to be directed in certain directions. Therefore, the gas flow in one direction can have a greater flow flux than the gas flow in other directions. Figure 1 In the example depicted, the diverter 170 redirects the gas flow from the remote plasma source 130 to flow radially outward to the outer regions 192, 193 (e.g., edge regions) of the nozzle assembly 189, rather than towards the inner regions 190, 191 (e.g., the central region). Therefore, in examples where the edges of the substrate 104 require enhanced processing with a higher flux density of reactive material, the diverter 170 can be used to guide the flow of reactive material to the desired edge location of the substrate 104. Reference will be made below. Figure 5 Further discussion on the configuration details of the shunt 170.

[0023] 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 and a second gas panel 102, the first gas panel 101 being configured to provide process gases for an abatement process to remove residual material after etching, and the second gas panel 102 being configured to provide process gases for an ashing process to remove photoresist or any other residue from the substrate 104.

[0024] The processing chamber 100 further includes a substrate support assembly 153 disposed within the internal processing volume 120 for supporting a substrate 104. A concentrating ring 160 may be disposed on the outer edge of the substrate support assembly 153. The concentrating ring 160 is used to hold the substrate 104 and also to modify the processing rate around the edge region of the substrate 104 during processing. A base support 180 may be inserted between the concentrating ring 160 and the surface of the substrate support assembly 153 to help support the concentrating ring 160 in proper positioning. The concentrating ring 160 is positioned and formed such that a step 168 is defined at the corner of the concentrating ring 160. The defined step 168 efficiently allows plasma or reactive material to flow in a direction close to the substrate bevel or substrate edge to assist the reactive material in reacting with the substrate edge or substrate bevel. Further details of the concentrating ring 160 will be referenced below. Figure 3A and Figure 3B Further explanation.

[0025] A substrate support assembly 153 is disposed within 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, wherein at least a portion of the substrate support assembly 153 is conductive and can be used as a process bias cathode by an RF bias power source 171 coupled to the substrate support assembly 153. The substrate disposed on the substrate support assembly 153 can be lifted and lowered by means of a wafer lifting rod (not shown) to facilitate the transfer of the substrate onto and off the substrate support assembly 153.

[0026] The controller 172 includes a central processing unit (CPU) 174, memory 176, and support circuitry 178 for controlling process sequence and regulating airflow and plasma processes executed in the processing chamber 100. The CPU 174 can be any form of general-purpose computer processor suitable for use in an industrial environment. Software routines, such as the processes implemented in the processing chamber 100, can be stored in memory 176, such as random access memory, read-only memory, floppy disk, hard disk drive, or other forms of digital storage. The support circuitry 178 is coupled to the CPU 174 and may include cache, clock circuitry, input / output systems, power supply, etc. Bidirectional communication between the controller 172 and various components of the processing chamber 100 is manipulated via a multitude of signal cables, collectively referred to as the signal bus, some of which are shown in... Figure 1 middle.

[0027] Figure 2This is a schematic perspective view of an example of a hub ring 160 used in a processing chamber 100 according to an embodiment of the present disclosure. The hub ring 160 may be in the form of a donut with a central opening 205. When the hub ring 160 is placed around the substrate support assembly 153, the diameter 210 of the central opening 205 may be adapted to the size of a substrate 104 positioned within the central opening 205 and having a desired diameter range (e.g., such as 200 mm, 300 mm, or 450 mm). In one example, the diameter 210 may be between approximately 11 inches and approximately 13 inches.

[0028] In one example, the concentrating 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 concentrating ring 160. The upper outer wall 167 and the upper inner wall 165 are connected by a top surface 163 of the upper body 164. The top surface 163 of the upper body 164 defines a flat surface parallel to the upper surface of the substrate support assembly 153. The lower body 162 is connected to the upper body 164, thereby forming a single body of the concentrating ring 160. In some examples, the lower body 162 and the upper body 164 can be separated and reassembled as needed, such as when mounted in the processing chamber 100 to surround the substrate support assembly 153.

[0029] 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 concentrating ring 160. Conversely, the lower inner wall 301 is formed by extending outwardly from the upper inner wall 165 toward the central opening 205 of the concentrating ring 160. In one example, the concentrating ring 160 may be made of a material containing a dielectric material (such as aluminum nitride, aluminum oxide, aluminum oxynitride, etc.).

[0030] Figure 3A Depicting along section line A-A' Figure 2 A cross-sectional view of the concentrator ring 160. A step 168 of the concentrator 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, the thickness 302 defining the height of the step 168. Figure 3AIn the example depicted, 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 sidewalls of the step 168. The lower body 162 has a thickness 310 (e.g., height) between about 0.25 mm and about 1 inch, which allows the central ring 160 to properly engage with the base support 180 disposed 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 example, the thickness 310 of the lower body 162 is between about 20% and about 50% greater than the thickness 302 of the upper body 164.

[0031] 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 through the upper body 164, has a width 169 ranging from approximately 0.5 inches to approximately 5 inches, and the width 169 also defines the width of the step 168. The exposed surface 315 is also the bottom surface of the step 168. In one example, the thickness 302 (or the sidewall height of the step 168) is substantially similar to or equal to the width 169 of the exposed surface 315 (or the bottom surface of the step 168). It should be noted that the dimensions of the step 168 formed in the concentrating ring 160 may be predetermined to allow sufficient space to assist the flow of reactive material from the internal processing volume 120 to the edge of the substrate located nearby. The step 168 can help retain reactive material that can be processed at the edge or bevel of the substrate for a longer period of time. The lower inner wall 301 is configured to contact or be adjacent to the edge of the substrate 104 to assist in retaining the substrate 104 in the desired location. The exposed surface 315 of the lower body 162 is substantially parallel to the top surface 163 of the upper body 164. The upper body 164 has a total width 314 between approximately 1 inch and approximately 5 inches.

[0032] Figure 3B Another example is depicted of a concentrated ring 300 that can be used to surround a substrate support assembly 153 within a processing chamber 100. Similar to... Figure 3A The concentrating ring 160 depicted in the image, and the concentrating ring 300 also have 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. The concentrating ring 300 is structurally similar to... Figure 3AThe concentrating ring 160, but the upper inner wall 356 of the concentrating ring 300 can be constructed differently. Unlike the substantially vertical upper inner wall 165 from the concentrating ring 160, the upper inner wall 356 of the concentrating ring 300 has an inclined surface 362 with an angle θ relative to the exposed surface 358 from the lower body 352. The angle θ is between about 20 degrees and about 110 degrees. It is believed that the inclined surface 362 of the upper inner wall 356 can help retain a larger amount of reactive material in the step 360 to facilitate reaction at the edges and angles of the substrate. The dimensions of the upper body 354 and the lower body 352 of the concentrating ring 300 can be... Figure 3A The concentrated ring 160 depicted in the text is similar to or the same as that depicted in the text.

[0033] Figure 4 Depicting Figure 1 A bottom view of the nozzle assembly 189. The nozzle assembly 189 has multiple zones 190, 191, 192, 193, each zone having a different number and density of pores 188 formed within it. At least two zones have a different number of pores 188 formed in the nozzle assembly 189. Furthermore, in some embodiments, the different zones may be made of different materials as needed. Zones 190, 191, 192, 193 may be formed in different geometric configurations or patterns, such as concentric rings, grids, or slice patterns, or other combinations of different geometries as needed. In some examples where an enhanced airflow of reactive material is desired at the edge of the substrate 104, the edge zones 192, 193 facing the edge of the substrate 104 may be configured to have a higher pore density. The density of zones 190, 191, 192, 193 may gradually decrease (e.g., gradient) to control a relatively smaller supply of reactive material to the central zones 190, 191 compared to the edge zones 192, 193. In some examples, the central regions 190 and 191 may not have pores. Therefore, from the edge region 193 to the central region 190 (e.g., from region 193 to subsequent regions 192, 191, and finally back to region 190), the open area gradually increases, causing the number and density of pores to gradually decrease as needed. In one example, the pore density decreases or increases by approximately 2% to approximately 20% relative to each adjacent region. The pores in each region may be aligned in a horizontal surface. The pores formed in different regions may or may not be horizontally aligned.

[0034] Figure 5A diverter 170 is depicted that can be disposed in the processing chamber 100 above the lower plate 199 of the nozzle assembly 189. The diverter 170 can be positioned in direct contact with the lower plate 199, or slightly above the lower plate 199 and spaced apart from the lower plate 199 at a desired distance. The diverter 170 has a conical shape. The diverter 170 has a tapered portion 502 toward the center, for example, the tapered portion 502 has a bottom end (or base) 504 that is wider at (or slightly above) the plane of the lower plate 199 than the distal end 506, i.e., a first dimension 508 is larger than a second dimension 510. It should be noted that the taper, shape, or size of the diverter 170, as well as the shape, position, and size of the diverter 170, can vary according to specific design and application requirements, taking into account various factors such as chamber size, pumping configuration, airflow velocity, enhanced flow configuration, etc. In addition to achieving certain desired processing rates or uniformity results, design parameters are also selected to provide a process with relatively wide margins.

[0035] In one example, the bottom end 504 is circular. A first dimension 508 is between approximately 1.5 inches and approximately 4 inches, and a 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 and approximately 40 times the size of the second dimension 510. The shunt 170 also has a height 512 (from the bottom end 504 to the distal end 506) between approximately 0.25 inches and approximately 1.5 inches. The shunt 170 may be made of a material containing aluminum.

[0036] In one example, the diverter 170 may be a solid body through which gas flow is not permitted (e.g., the taper 502 comprises a solid body formed from the bottom end 504 to the distal end 506). In another example, the diverter 170 is a hollow member from the bottom end 504 to the distal end 506 (e.g., the taper 502 is a hollow body having a cavity formed from the bottom end 504 to the distal end 506) so that open flow communication from the distal end 506 to the bottom end 504 is permitted when gas or reactive material flows through. In the example where the diverter 170 is a hollow member, gas or reactive material from the remote plasma source 130 may also be directed to the central region 190 where the hollow member is located.

[0037] In one embodiment, the airflow from gas panels 102, 101 flows vertically downward through channel 155 connected to splitter 170 (e.g., ...). Figure 1(Illustration). The airflow is then deflected or redirected by the splitter 170 to the pores 188, primarily located in the edge regions 193, 192. Therefore, the airflow does not flow to the central regions 190, 191, which have fewer or no pores. By adjusting the position, geometry, and size of the splitter 170, the spatial or lateral distribution of ions, neutral substances, and reactive substances passing through it can be controlled, which in turn allows for tuning the substrate edge processing rate distribution. Although in Figure 1 In the example depicted, the splitter 170 is centrally located on or above the lower plate 199 of the nozzle assembly 189; however, the splitter 170 may also be located in other locations or provided in different shapes and sizes to establish a desired flow pattern suitable for other application requirements. During processing, the process gas is ignited and formed into a remote plasma source, which is to be supplied from the remote plasma source 130 to the internal processing volume 120.

[0038] Although embodiments of this disclosure have been described above in the context of processing chamber applications, these embodiments can be applied to any process chamber, such as a loading locking chamber or a transfer chamber. In particular, embodiments of this disclosure can be used in applications where enhanced substrate edge processing efficiency and increased processing rates at substrate edges are desired.

[0039] Although the foregoing embodiments relating to this disclosure are available, other and further embodiments of this disclosure may be devised without departing from the basic scope of this disclosure, and the scope of this disclosure is defined by the appended claims.

Claims

1. A processing chamber, comprising: A chamber body defining an internal processing area within a processing chamber; and A nozzle assembly disposed in the processing chamber, wherein the nozzle assembly has at least four zones having different pore densities, wherein the at least four zones include a first zone in a central region and a second zone in an edge region, wherein the first zone located in the central region has no pores and wherein the pore density of the at least four zones gradually decreases from the edge region to the central region; A substrate support assembly is disposed in the internal processing area of ​​the processing chamber; as well as A focus ring, disposed on the edge of the substrate support assembly and surrounding the substrate support assembly, the focus ring comprising: inner and outer periphery; The upper body extends inward from the outer periphery to the upper inner wall, and the upper body has a top surface and a bottom surface; A lower body extending from the inner periphery, the lower body having an exposed upper surface and a lower surface, the exposed upper surface extending to an upper inner wall, and the lower surface extending below the bottom surface at the inner periphery, the inner periphery being configured to surround the edge of the substrate when the substrate is disposed on the substrate support assembly; and A step, formed by the intersection of the upper inner wall and the exposed upper surface, wherein the height of the upper inner wall is equal to the length of the exposed upper surface.

2. The processing chamber as claimed in claim 1, further comprising: A flow divider is disposed above the lower plate of the nozzle assembly, wherein the flow divider extends above the lower plate to a height between 0.25 inches and 1.5 inches.

3. The processing chamber of claim 2, wherein the shunt is configured to communicate with a remote plasma source.

4. The processing chamber of claim 2, wherein the shunt has a base that tapers upward to a distal end, wherein the base has a base length between 1.5 inches and 4 inches, and the distal end has an end length between 0.05 inches and 0.5 inches.

5. The processing chamber of claim 2, wherein the diverter has a base that tapers upward to a distal end and has a hollow space from the base to the distal end.

6. The processing chamber of claim 5, wherein the base has a first dimension and the distal end has a second dimension, wherein the first dimension is larger than the second dimension.

7. The processing chamber of claim 6, wherein the first dimension is between 20 and 40 times larger than the second dimension.

8. The processing chamber of claim 6, wherein the base is circular in shape.

9. The processing chamber of claim 2, wherein the diverter is made of an aluminum-containing material.

10. The processing chamber of claim 1, wherein the step has inclined sidewalls.

11. The processing chamber of claim 1, wherein the concentrating ring has an upper body disposed on a lower body, wherein the lower body has a first thickness greater than the second thickness of the upper body.

12. The processing chamber of claim 11, wherein the upper body exposes the surface of the lower body, thereby defining the bottom surface of the step.

13. The processing chamber of claim 1, wherein the concentrating ring is made of an aluminum-containing material.

14. A method for enhancing the efficiency of substrate edge processing, comprising: The gas flow from the remote plasma source is diverted to the edge region of the nozzle assembly via a splitter; The airflow is guided through the apertures in the edge region of the nozzle assembly toward the edge of the substrate. The nozzle assembly includes: A nozzle plate having a plurality of pores formed therein, wherein the nozzle plate has at least four regions having different pore densities, wherein the at least four regions have a first region in a central region and a second region in an edge region, wherein the first region located in the central region has no pores, and wherein the pore density of the at least four regions gradually decreases from the edge region to the central region; and The airflow is retained around the edge of the substrate by steps formed by a concentrated ring surrounding the substrate according to any one of claims 1 to 13.

15. The method of claim 14, wherein the splitter is located above the nozzle assembly.

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