Spray head

Abstract

The invention provides a spray header, comprising: a panel comprising a first surface, a second surface and a plurality of through holes penetrating through the first surface and the second surface; the inflation cavity is at least partially limited by the first surface of the panel; the first surface is provided with a plurality of through holes, the second surface is opposite to the substrate supporting piece, and the first surface protrudes in the direction away from the substrate supporting piece, so that the lengths of the through holes are the largest in the center of the panel and the smallest in the edge of the panel. And the lengths of the through holes from the center to the edge of the panel are gradually reduced, so that the resistance of the gas to the through holes is gradually reduced from the center to the edge of the panel, the flow uniformity of the gas flowing out of the second surface on the panel is improved, and the uniformity of the thickness of a deposited film on the surface of the substrate is adjusted.

Description

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. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the structure of a shower head in one embodiment of the present invention.

[0016] Figure 2 Schematic diagram of the structure of a shower head in another embodiment of the present invention.

[0017] Figure 3 Schematic diagram of the structure of a shower head in another embodiment of the present invention. DETAILED DESCRIPTION

[0018] 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 perspectives and applications without departing from the spirit of the present invention.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] like Figure 1 As shown, this embodiment provides a showerhead 100, including a gas inlet 210, which is fluidically connected to other fluid conduit hardware, such as pipes and valves. Figure 1 In the embodiment, the gas inlet 210 is fluidly connected to the pipe 211, which can be a rod for suspending the shower head 100. The shower head 100 also includes a back plate 230, a face plate 220, and a gas filling chamber 240. The back plate 230 is in communication with the pipe 211 and is disposed opposite the face plate 220. The back plate 230 and the face plate 220 at least partially define the gas filling chamber 240. An external gas supply device supplies gas to the gas filling chamber 240 through the gas inlet 210. Exemplarily, the gas inlet 210 is an opening formed on the back plate 230. The gas in the external gas supply device is sequentially passed through the pipe 211 and the gas inlet 210 into the gas filling chamber 240.

[0025] like Figure 1In the figure, 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, and 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 the entire extension direction. The second surface 222 is closer to the substrate support than the first surface 221, and 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 is dissociated into plasma below the panel 220. The dissociated plasma deposits a thin film on the surface of a substrate placed on the substrate support. Specifically, in one embodiment, RF power is applied between the shower head 100 as an upper electrode and the substrate support as a lower electrode to excite the gas flowing out of the panel 220 into plasma for processing the substrate. The first surface 221 and the second surface 222 extend from the center of the panel to the edge 229 of the panel 220, and the thickness of the panel 220 gradually decreases from the center of the panel to the edge 229 of the panel 220. For example, in Figure 1 In the illustrated embodiment, the first surface 221 may be a slightly conical surface, and the first surface 221 gradually reduces the thickness of the panel 220 in a downwardly inclined manner from the center of the panel 220 to the edge 229. In the cross section of the first surface 221, the direction from the center of the panel 220 to the edge 229 is an inclined straight line. In an embodiment not shown, the cross section of the first surface may be a curve from the center of the panel to the edge, and the first surface reduces the thickness of the panel in a curved manner from the center to the edge. Figure 1 In the embodiment of , the first surface 221 is a smooth surface. Figure 2 and Figure 3 In the illustrated embodiment, the first surface 221 may 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. Figure 1 In FIG. 2 , 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, Figure 1In the embodiment shown in FIG, 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 to the edge 229 of the panel 220. The gas inlet 210 is fluidically connected to the gas filling cavity 240. Gas enters the gas filling cavity 240 from the gas inlet 210 and flows from the center to the edge 229 of the panel along the first surface 221. The gas flow rate gradually decreases from the center to the edge 229 of the panel on the first surface 221, while the length of the through hole 223 gradually decreases from the center to the edge 229 of the panel 220. This makes the resistance to gas passing through the through hole 223 gradually decrease from the center to the edge 229 of the panel, thereby improving the flow uniformity of the gas flowing out from the second surface 222 of the panel 220.

[0026] In some embodiments, the inner surface of the back plate 230 opposite to the first surface 221 of the panel 220 at least partially defines the drainage portion. Figure 2 In the illustrated embodiment, the inner surface of the back plate 230 opposite to the first surface 221 of the panel 220 defines a drainage portion 231, and gas enters the gas filling cavity 240 from the gas inlet 210. Under the drainage action of the drainage portion 231, the gas flows radially outward from the gas inlet 210 to the panel 220. Figure 2 The inner surface of the middle back plate 230 is a downwardly inclined surface extending radially outward, and the inclined surface is a drainage portion 231. Figure 3 In the embodiment shown in , the inner surface portion of the back plate 230 opposite to the first surface 221 of the panel 220 defines a drainage portion 232 , and gas enters the gas filling cavity 240 from the gas inlet 210 , and under the drainage action of the drainage portion 232 , the gas flows to the edge 229 of the panel 220 . Figure 3 Part of the inner surface of the mid-back plate 230 includes a downwardly inclined surface extending radially outward, and the inclined surface is a drainage portion 232. Figure 3 Compared with Figure 2 The area of ​​the downwardly inclined surface of the back plate 230 in the embodiment is greater than Figure 3 The area of ​​the downwardly inclined surface of the mid-back plate 230 is such that Figure 3 The volume of the air-filled cavity 240 defined by the middle back plate 230 and the panel 220 is smaller than Figure 2 The gas filling chamber 240 in the external gas supply device can be filled with gas more quickly. Figure 3 The middle gas-filled cavity 240 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 by the cleaning gas.

[0027] In some embodiments, the flow distribution of the gas in the gas filling chamber 240 can be improved by setting a baffle inside the shower head 100. Specifically, a baffle is set in the center below the gas inlet 210. Figure 2In the embodiment shown, a baffle 260 is centrally provided below the gas inlet 210. The baffle 260 includes a circular baffle 261. Gas enters the gas filling 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 Figure 2 In the illustrated embodiment, 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. The gas enters the gas-filled chamber 240 from the gas inlet 210 and reaches the circular baffle 261. The gas flows laterally under the action of the circular baffle 261 and flows to the panel 220 through the edge of the annular baffle 262 and the central hole 263 in the middle of the annular baffle 262. Exemplarily, the diameter of the circular baffle 261 is larger than the diameter of the central hole 263, which can better guide the lateral flow of the gas. The gas inlet 210 is collinear with the central axis of the panel 220, and the central axes of the circular baffle 261 and the annular baffle 262 are collinear with the central axis of the gas inlet 210. In other words, the central axis 228 of the gas inlet 210, the panel 220, the circular baffle 261 and the annular baffle 262 are collinear. Figure 2 In the illustrated embodiment, the circular baffle 261 and the annular baffle 262 are fixed to the back plate 230 via fixing posts 264 .

[0028] 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.

[0029] 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.

Images