Spray head

Abstract

Provided in the present invention is a spray head, comprising: a panel, which comprises a first surface, a second surface, and several through holes passing through the first surface and the second surface; and an inflation cavity, which is at least partially defined by the first surface of the panel, wherein the second surface is opposite a substrate support member, and the first surface bulges away from the substrate support member, such that the length of the several through holes is at the maximum at the center of the panel and at the minimum at the edge of the panel. In the spray head of the present invention, the flow of gas on the first surface gradually decreases from the center of the panel to the edge thereof, and the length of the through holes gradually decreases from the center of the panel to the edge of thereof, such that the resistance of the through holes to the gas gradually decreases from the center of the panel to the edge thereof, thereby improving the flow uniformity of the gas flowing out from the second surface of the panel, and adjusting the uniformity of the thickness of a deposited film on a surface of a substrate.

Description

sprinkler head Technical Field

[0001] The invention belongs to the technical field of semiconductors and relates to a shower head used in substrate processing equipment. Background Art

[0002] Plasma enhanced chemical vapor deposition (PECVD) equipment processes substrates. The process deposits various dielectric films on the substrate surface. The thickness uniformity of the film directly affects the film properties and yield.

[0003] Process gases flow through the showerhead of a PECVD system into the equipment, depositing thin films on the substrate surface. The uniformity of the gas flow significantly impacts the uniformity of the film deposited on the substrate surface. Airflow is difficult to control, so a rational showerhead structure is required to ensure that the airflow meets the process requirements. Designing a showerhead that adjusts the airflow is crucial. Summary of the Invention

[0004] The object of the present invention is to provide a shower head with adjustable output gas flow rate, which can improve the thickness uniformity of a thin film deposited on a substrate surface during a PECVD process.

[0005] To achieve the above-mentioned objectives and other related objectives, the present invention proposes a shower head, comprising: a panel, comprising a first surface, a second surface, and a plurality of through holes extending through the first surface and the second surface; an air-filled cavity, at least partially defined by the first surface of the panel; the second surface is opposite to the substrate support below the shower head, and the first surface protrudes in a direction away from the substrate support so that the length of the plurality of through holes is maximum at the center of the panel and minimum at the edge of the panel.

[0006] Optionally, the first surface is a smooth surface.

[0007] Optionally, the first surface is a stepped surface.

[0008] Optionally, the second surface is at a uniform distance from the substrate support.

[0009] Optionally, the thickness of the panel gradually decreases from the center to the edge of the panel.

[0010] Optionally, the shower head further comprises a gas inlet for introducing gas into the gas-filled cavity, and a vertical distance between the second surface and the gas inlet gradually increases from the center to the edge of the panel.

[0011] Optionally, a baffle is further provided in the gas-filled cavity, and a central axis of the baffle is collinear with a central axis of the gas inlet.

[0012] Optionally, the baffle includes a circular baffle and an annular baffle, and the annular baffle is located between the circular baffle and the panel, so that the gas flows toward the annular baffle after passing through the circular baffle and diffuses from the central hole and edge of the annular baffle to the first surface of the panel.

[0013] Optionally, the shower head further includes a back plate, wherein an inner surface of the back plate opposite to the first surface at least partially defines a flow guide portion.

[0014] As described above, in the shower head of the present invention, since the gas flow rate gradually decreases from the center to the edge of the panel on the first surface, and the length of the through hole from the center to the edge of the panel gradually decreases, the resistance of the gas to the through hole gradually decreases from the center to the edge of the panel, thereby improving the flow uniformity of the gas flowing out from the second surface of the panel and adjusting the uniformity of the thickness of the deposited film on the surface of the substrate.

[0015] Summary of the Figures

[0016] The features and properties of the present invention are further described by the following examples and accompanying drawings.

[0017] FIG1 is a schematic structural diagram of a shower head according to an embodiment of the present invention.

[0018] FIG2 is a schematic structural diagram of a shower head according to another embodiment of the present invention.

[0019] FIG3 is a schematic structural diagram of a shower head in another embodiment of the present invention.

[0020] Preferred embodiments of the present invention

[0021] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0022] For example, when describing the embodiments of the present invention, cross-sectional views of device structures may be partially enlarged to scale for ease of explanation. Furthermore, these schematic views are merely illustrative and should not limit the scope of the present invention. Furthermore, in actual manufacturing, three-dimensional dimensions, including length, width, and depth, should be included.

[0023] For ease of description, spatially relative terms such as "under," "below," "below," "below," "above," and "on" may be used herein to describe the relationship of one element or feature to other elements or features shown in the drawings. It will be understood that these spatially relative terms are intended to encompass orientations of the device in use or operation in addition to the orientation depicted in the drawings. Additionally, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may be present. As used herein, "between" is inclusive of both endpoints.

[0024] In the context of the present application, a structure described as a first feature being "above" a second feature may include embodiments where the first and second features are formed in direct contact, and may also include embodiments where an additional feature is formed between the first and second features, such that the first and second features may not be in direct contact.

[0025] It should be noted that the illustrations provided in this embodiment are only used to schematically illustrate the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0026] For the purposes of this disclosure, the term "fluid connection" is used for volumes, plenums, holes, etc. that can be connected to each other to form a fluid connection.

[0027] As shown in FIG1 , this embodiment provides a showerhead 100, comprising a gas inlet 210, which is fluidically connected to other fluid conduit hardware, such as a pipe or a valve. Exemplarily, in FIG1 , the gas inlet 210 is fluidically connected to a pipe 211, which may be a rod for suspending the showerhead 100. The showerhead 100 further comprises a back plate 230, a face plate 220, and a gas-filled cavity 240. The back plate 230 is in communication with the pipe 211 and is disposed opposite the face plate 220, and the two at least partially define the gas-filled cavity 240. An external gas supply device supplies gas into the gas-filled cavity 240 through the gas inlet 210. Exemplarily, the gas inlet 210 is an opening formed on the back plate 230, and gas in the external gas supply device is sequentially passed through the pipe 211 and the gas inlet 210 into the gas-filled cavity 240.

[0028] As shown in Figure 1, the panel 220 includes a first surface 221, a second surface 222, and a plurality of through-holes 223 extending through the first and second surfaces 221 and 222. The first surface 221 of the panel 220 at least partially defines a gas-filled cavity 240. The first surface 221 is a non-planar surface, while the second surface 222 is a planar surface. The second surface 222 is disposed opposite a substrate support (not shown), and the distance between the second surface 222 and the substrate support is consistent. More specifically, the distance between the second surface 222 and the substrate support remains consistent throughout its entire extension direction. The second surface 222 is closer to the substrate support than the first surface 221, while the first surface 221 protrudes away from the substrate support. After the gas flows out of the through-holes 223 of the panel 220, it dissociates into plasma below the panel 220. The dissociated plasma then deposits a thin film on the surface of a substrate placed on the substrate support. Specifically, in one embodiment, radio frequency power is applied between the showerhead 100, which serves as an upper electrode, and the substrate support, which serves as a lower electrode, to energize the gas flowing from the panel 220 into a plasma for processing the substrate. A first surface 221 and a second surface 222 extend from the center of the panel to an edge 229 of the panel 220, and the thickness of the panel 220 gradually decreases from the center to the edge 229 of the panel 220. For example, in the embodiment shown in FIG1 , the first surface 221 may be a slightly conical surface, with the thickness of the panel 220 gradually decreasing in a downwardly sloping manner from the center to the edge 229 of the panel 220. The cross-section of the first surface 221 is an inclined straight line from the center to the edge 229 of the panel 220. In other embodiments not shown, the cross-section of the first surface may be a curve from the center to the edge of the panel, with the thickness of the first surface decreasing in a curved manner from the center to the edge. In the embodiment shown in FIG1 , the first surface 221 is a smooth surface. In the embodiments shown in Figures 2 and 3, the first surface 221 can be stepped or stepped, and the first surface 221 reduces the thickness of the panel 220 in a stepped manner from the center of the panel to the edge 229. Referring to Figure 1, the vertical distance between the second surface 222 and the gas inlet 210 gradually increases from the center of the panel to the edge 229 of the panel 220. The length of the through hole 223 (vertical direction in the figure) is the largest at the center of the panel 220 and the smallest at the edge 229 of the panel 220. For example, in the embodiment shown in Figure 1, the length of the through hole 223 that penetrates the first surface 221 and the second surface 222 of the panel 220 gradually decreases from the center of the panel 220 to the edge 229.The gas inlet 210 is fluidically connected to the inflation cavity 240. The gas enters the inflation cavity 240 from the gas inlet 210 and flows from the center of the panel to the edge 229 along the first surface 221. The gas flow gradually decreases from the center of the panel to the edge 229 on the first surface 221, and the length of the through hole 223 from the center of the panel 220 to the edge 229 gradually decreases, so that the resistance of the gas passing through the through hole 223 gradually decreases from the center of the panel to the edge 229, thereby improving the flow uniformity of the gas flowing out from the second surface 222 on the panel 220.

[0029] In some embodiments, the inner surface of the backplate 230 opposite the first surface 221 of the panel 220 at least partially defines a flow guide. In the embodiment shown in FIG2 , the inner surface of the backplate 230 opposite the first surface 221 of the panel 220 defines the flow guide 231. Gas flows from the gas inlet 210 into the plenum chamber 240. Under the guidance of the flow guide 231, the gas flows radially outward from the gas inlet 210 toward the panel 220. In FIG2 , the inner surface of the backplate 230 is a radially outward-extending, downwardly inclined surface, which is the flow guide 231. In the embodiment shown in FIG3 , the inner surface of the backplate 230 opposite the first surface 221 of the panel 220 partially defines the flow guide 232. Gas flows from the gas inlet 210 into the plenum chamber 240. Under the guidance of the flow guide 232, the gas flows toward the edge 229 of the panel 220. In FIG3 , a portion of the inner surface of the backplate 230 includes a radially outward-extending, downwardly inclined surface, which is the flow guide 232. Compared with Figure 3, the area of ​​the downwardly inclined surface of the back plate 230 in the embodiment of Figure 2 is larger than the area of ​​the downwardly inclined surface of the back plate 230 in Figure 3, so that the volume of the gas-filled cavity 240 defined by the back plate 230 and the panel 220 in Figure 3 is smaller than the gas-filled cavity 240 in Figure 2, and the gas in the external gas supply device can fill the gas-filled cavity 240 in Figure 3 more quickly, which can reduce the time for the process gas to reach the substrate surface from the gas-filled cavity 240, and can also reduce the time for the process gas in the gas-filled cavity 240 to be purged and cleared by the cleaning gas.

[0030] In some embodiments, the flow distribution of gas in the plenum chamber 240 can be improved by providing a baffle within the showerhead 100. Specifically, a baffle is centrally located below the gas inlet 210. For example, referring to the embodiment shown in FIG2 , a baffle 260 is centrally located below the gas inlet 210. The baffle 260 includes a circular baffle 261. Gas enters the plenum chamber 240 from the gas inlet 210, reaches the circular baffle 261, and diffuses radially outward under the action of the circular baffle 261. In another embodiment, referring to the embodiment shown in FIG2 , the baffle 260 includes a circular baffle 261 and an annular baffle 262. The annular baffle 262 is located between the circular baffle 261 and the panel 220. Gas enters the plenum chamber 240 from the gas inlet 210, reaches the circular baffle 261, and flows laterally under the action of the circular baffle 261. The gas flows through the edge of the annular baffle 262 and the center hole 263 in the center of the annular baffle 262 toward the panel 220. For example, the diameter of circular baffle 261 is larger than the diameter of central hole 263, which can better guide the lateral flow of gas. The gas inlet 210 is collinear with the central axis of the panel 220, and the central axes of circular baffle 261 and annular baffle 262 are collinear with the central axis of the gas inlet 210. In other words, the central axes 228 of the gas inlet 210, panel 220, circular baffle 261, and annular baffle 262 are collinear. Referring to the embodiment shown in FIG2 , circular baffle 261 and annular baffle 262 are secured to the backplate 230 via fixing posts 264.

[0031] In this embodiment, the gas enters the gas filling cavity 240 from the gas inlet 210 and flows from the center of the panel to the edge 229 along the first surface 221. Since the gas flow gradually decreases from the center of the panel to the edge 229 on the first surface 221, and the length of the through hole 223 from the center of the panel 220 to the edge 229 gradually decreases, the resistance encountered by the gas passing through the through hole 223 gradually decreases from the center of the panel to the edge 229, thereby improving the flow uniformity of the gas flowing out of the panel 220 and adjusting the uniformity of the thickness of the deposited film on the substrate surface.

[0032] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A shower head, characterized in that: include: A panel comprising a first surface, a second surface, and a plurality of through holes passing through the first surface and the second surface; a gas-filled cavity at least partially defined by the first surface of the panel; The second surface is opposite to the substrate support under the shower head, and the first surface protrudes away from the substrate support so that the lengths of the plurality of through holes are maximum at the center of the panel and minimum at the edge of the panel.

2. The shower head according to claim 1, wherein: The first surface is a smooth surface.

3. The shower head according to claim 1, wherein: The first surface is a stepped surface.

4. The shower head according to claim 1, wherein: The second surface is at a consistent distance from the substrate support.

5. The shower head according to claim 1, wherein: The thickness of the panel gradually decreases from the center to the edge of the panel.

6. The shower head according to claim 1, wherein: It also includes a gas inlet for introducing gas into the gas-filled cavity, and the vertical distance between the second surface and the gas inlet gradually increases from the center to the edge of the panel.

7. The shower head according to claim 1, wherein: A baffle is further provided in the gas filling chamber, and a central axis of the baffle is collinear with a central axis of the gas inlet.

8. The shower head according to claim 7, wherein: The baffle includes a circular baffle and an annular baffle, and the annular baffle is located between the circular baffle and the panel, so that the gas flows toward the annular baffle after passing through the circular baffle and diffuses from the central hole and edge of the annular baffle to the first surface of the panel.

9. The shower head according to claim 1, wherein: A back plate is further included, wherein an inner surface of the back plate opposite to the first surface at least partially defines a flow guide portion.

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