Process top cover and vapor deposition equipment

Abstract

The utility model discloses a process top cover and vapor deposition equipment, and belongs to the field of semiconductor equipment, the process top cover is used for vapor deposition equipment, and the process top cover comprises a base material with an annular structure; the corrosion-resistant coating covers the upper surface of the base material; and the surface roughness of at least part of the lower surface of the process top cover is 3-15 microns. According to the utility model, by increasing the roughness of the lower surface of the process top cover, the binding force between the lower surface of the process top cover and the attachments is increased, so that the attachments are prevented from falling off in the wafer growth process, and the growth quality of a wafer film is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of semiconductor equipment, especially related to a process top cover and vapor deposition equipment. BACKGROUND

[0002] The reaction cavity of the existing MOCVD (Metal-organic Chemical Vapor Deposition) equipment includes a cavity and a cavity top cover. A tray is arranged in the reaction cavity and used for carrying one or more wafers. A process top cover is arranged below the cavity top cover, and a reaction area is formed between the lower surface of the process top cover and the upper surface of the tray. The process top cover is usually made of graphite base material, and the surface of the process top cover is coated with a coating layer having corrosion resistance, which can prevent process gases such as hydrogen from penetrating into the reaction cavity from the back surface of the process top cover.

[0003] However, in actual application, the following problems exist: During the growth process, process gases not only deposit on the surface of the wafer to form a thin film, but also form attachments on the lower surface of the process top cover. Since the bonding force between the attachments and the process top cover is weak, the attachments are prone to falling off during the growth of the wafer, thereby affecting the quality of the thin film on the wafer surface. Therefore, the process top cover needs to be cleaned frequently or the reaction cavity needs to be opened to replace the process top cover, which greatly reduces the production efficiency.

[0004] The statements herein only provide background technology related to the utility model and do not necessarily constitute prior art. CONTENT OF THE UTILITY MODEL

[0005] The utility model aims to provide a process top cover and vapor deposition equipment to reduce the falling of attachments on the process top cover and improve the quality of thin film growth and production efficiency.

[0006] To achieve the above purpose, the utility model provides a process top cover for a vapor deposition equipment, which comprises: a base material having a ring structure; a corrosion-resistant coating covering the upper surface of the base material; and the surface roughness of at least part of the lower surface of the process top cover is 3 μm ~ 15 μm.

[0007] For example, the surface roughness of at least part of the lower surface of the process top cover is 5 μm ~ 10 μm.

[0008] For example, the lower surface of the process top cover is the lower surface of the base material.

[0009] For example, the corrosion-resistant coating covering the upper surface of the base material is a first corrosion-resistant coating, the lower surface of the base material is covered with a second corrosion-resistant coating, and the lower surface of the process top cover is the lower surface of the second corrosion-resistant coating.

[0010] In an example, the lower surface of the substrate includes a first region and a second region, the second region is located at an outer edge of the substrate and is arranged around the first region; wherein the surface roughness of the first region is greater than the surface roughness of the second region, and the surface roughness of the first region is 3 μm ~ 15 μm.

[0011] In an example, the surface roughness of the first region is 5 μm ~ 10 μm.

[0012] In an example, the second region is covered with a corrosion-resistant coating.

[0013] In an example, the surface roughness of the second region is 0.5 μm ~ 5 μm.

[0014] In an example, the ratio of the radial width of the second region of the lower surface of the substrate to the radial width of the substrate ranges from 5% to 15%.

[0015] In an example, the upper surface of the substrate without roughening treatment has a first surface roughness, and the upper surface of the substrate after roughening treatment has a second surface roughness, the second surface roughness is 2 to 50 times the first surface roughness.

[0016] In an example, the surface roughness of the upper surface of the substrate is 0.5 μm ~ 5 μm.

[0017] In an example, the thickness of the corrosion-resistant coating ranges from 20 μm to 50 μm.

[0018] In an example, the surface roughness of the corrosion-resistant coating is 0.5 μm ~ 5 μm.

[0019] In an example, the surface roughness of the first corrosion-resistant coating and the second corrosion-resistant coating is 3 μm ~ 15 μm.

[0020] In an example, the surface roughness of the first corrosion-resistant coating and the second corrosion-resistant coating is 5 μm ~ 10 μm.

[0021] In an example, the surface roughness of the upper surface and the lower surface of the substrate is 3 μm ~ 15 μm.

[0022] In an example, the surface roughness of the upper surface and the lower surface of the substrate is 5 μm ~ 10 μm.

[0023] In an example, the surface roughness of the upper surface of the substrate is 0.5 μm ~ 5 μm, and the surface roughness of the first corrosion-resistant coating is 0.5 μm ~ 5 μm.

[0024] For example, the flatness of the upper surface of the process top cover is less than or equal to 0.8 mm, or the flatness of both the upper surface and the lower surface of the process top cover is less than or equal to 0.8 mm.

[0025] For example, the flatness of the upper surface of the process top cover is less than or equal to 0.5 mm, or the flatness of both the upper surface and the lower surface of the process top cover is less than or equal to 0.5 mm.

[0026] For example, the corrosion-resistant coating comprises a pyrolytic carbon coating, and the substrate is made of graphite.

[0027] The utility model also provides a kind of vapor deposition equipment, it includes: reaction cavity;Gas inlet mechanism, it is set in the top of the reaction cavity, for conveying gas to the reaction cavity;Tray, it is set in the reaction cavity, for carrying wafer;The cavity top cover of the reaction cavity is below and is provided with the process top cover as described above, the process top cover is around the gas inlet mechanism setting.

[0028] For example, the vapor deposition equipment further comprises: a temperature control plate disposed between the cavity top cover and the process top cover, and having a gap between the process top cover.

[0029] For example, the ratio of the flatness of the upper surface of the process top cover to the minimum vertical height of the gap is less than or equal to 40%.

[0030] For example, the minimum vertical height of the gap between the lower surface of the temperature control plate and the upper surface of the process top cover is not more than 2 mm.

[0031] For example, the bottom of the cavity top cover is circumferentially provided with a support ring, and the side of the process top cover close to the gas inlet mechanism is provided with a step for lapping on the support ring.

[0032] For example, the lower surface of the substrate comprises a first region and a second region, the second region is located at the outer edge of the substrate and is arranged around the first region; wherein the surface roughness of the first region is greater than the surface roughness of the second region, the surface roughness of the first region is 3 μm~15 μm, and the first region covers the wafer on the tray.

[0033] Compared with the prior art, the technical scheme of the utility model has at least the following beneficial effects:

[0034] The process top cover and the vapor deposition equipment provided by the utility model increase the surface roughness of the lower surface of the process top cover to 3 μm~15 μm, increase the bonding force between the lower surface of the process top cover and the adhering matter, and thereby inhibit the falling of the adhering matter during the wafer growth process.

[0035] Further, by increasing the surface roughness of the substrate before coating the corrosion-resistant coating, the adhesion between the corrosion-resistant coating and the surface of the substrate is increased, the corrosion-resistant coating is less likely to fall off the process cover, and the quality of wafer thin film growth is further improved.

[0036] In the vapor deposition device, the ratio of the flatness of the upper surface of the process cover to the minimum vertical height of the gap is set within 40%, which can improve the temperature regulation accuracy of the process cover, and further improve the temperature distribution uniformity in the reaction chamber, and improve the product yield. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is a structural schematic view of a vapor deposition device;

[0038] Figure 2 is a structural schematic view of a process cover of an embodiment of the present application;

[0039] Figure 3 is a sectional view of a process cover of an embodiment of the present application;

[0040] Figure 4 is a bottom view of a process cover of an embodiment of the present application;

[0041] Figure 5 is a sectional view of a process cover of another embodiment of the present application;

[0042] Figure 6 is a sectional view of a process cover of still another embodiment of the present application;

[0043] Figure 7 is a structural schematic view of a vapor deposition device of an embodiment of the present application. DETAILED DESCRIPTION

[0044] The process cover and the vapor deposition device of the present application are further described in detail below in combination with the drawings and the specific embodiments. The advantages and features of the present application will be more apparent according to the following description. It should be noted that the drawings are greatly simplified and all use non-precise proportions, only to facilitate, clear and assist the purpose of describing the embodiments of the present application. In order to make the purpose, features and advantages of the present application more apparent and easy to understand, please refer to the drawings. It should be noted that the structures, proportions, sizes, etc. shown in the drawings attached to the specification are only used to cooperate with the content disclosed in the specification, so that those skilled in the art can understand and read, and are not used to limit the conditions of the implementation of the present application, so they do not have the technical essence, any modification of the structure, change of the proportion relationship or adjustment of the size, as long as it does not affect the effect and purpose that can be achieved by the present application, it should still fall within the scope of the technical content disclosed by the present application.

[0045] Figure 1 The invention relates to a vapor deposition apparatus 200, which has a reaction chamber 201 in which a wafer W can be processed. The reaction chamber 201 includes a chamber cover 211 and a chamber body 212. The chamber cover 211 covers the chamber body 212, and the chamber cover 211 and the chamber body 212 together form an airtight internal processing space. Figure 1 The chamber body 212 is shown in FIG as being cylindrical, but may be of other shapes, such as square, hexagonal, octagonal, or any other suitable shape.

[0046] like Figure 1 As shown, an inlet mechanism 203 (typically made of corrosion-resistant stainless steel with good thermal conductivity) is positioned at the top of the reaction chamber 201. A tray 202 is positioned within the reaction chamber 201, below and opposite the inlet mechanism 203. The upper surface of the tray 202 is used to support one or more wafers W. A reaction area is formed between the upper surface of the tray 202 and the chamber top cover 211. The inlet mechanism 203 is connected to an external process gas supply (not shown) via a gas line to deliver process gases into the reaction area. The process gases may include carrier gases and process gases, which may include Group III and Group V gases. In a typical metal organic chemical vapor deposition process, the carrier gas may be nitrogen, hydrogen, or argon. An exhaust mechanism 205 is also positioned at the bottom of the reaction chamber 201 to discharge gases within the reaction chamber 201, including waste gases generated by the reaction and some process gases that have not yet participated in the reaction.

[0047] The material of the tray 202 is usually graphite, which has good thermal conductivity. A heating device 230 is provided under the tray 202. The heating device 230 heats the tray 202, and the tray 202 then transfers the heat energy provided by the heating device 230 to the wafer W. The process gas reacts at a specific temperature and is deposited on the wafer W to form a thin film of the desired material. Figure 1As shown, a process top cover 204 made of graphite is disposed below the chamber top cover 211 to prevent process gas from forming deposits on the bottom surface of the chamber top cover 211. A purge gas flows between the process top cover 204 and the chamber top cover 211 to temperature regulate the process top cover 204, which enters from gas inlets (not shown) on the chamber top cover 211 and flows along the top surface of the process top cover 204, and finally exits from the exhaust mechanism 205 at the bottom of the reaction chamber 201. Further, to improve the corrosion resistance of the process top cover 204, a pyrolytic carbon coating (PG coating) is applied to the surface of the process top cover 204 to prevent the purge gas (e.g., hydrogen) from penetrating into the reaction chamber 201 from the process top cover 204, and to avoid the influence of the penetrated purge gas on the composition of the process gas in the reaction chamber 201.

[0048] However, in actual use, during the growth process, the process gas not only deposits on the surface of the wafer W to form a thin film, but also forms deposits on the bottom surface of the process top cover 204. Since the binding force between the deposits and the process top cover is weak, the deposits are prone to falling on the wafer during the wafer growth process, thereby affecting the quality of the thin film on the wafer surface. Therefore, the process top cover needs to be cleaned frequently or the reaction chamber needs to be opened to replace the process top cover, which greatly reduces the production efficiency.

[0049] To overcome the above-mentioned defects, the utility model provides a process top cover for use in a vapor deposition apparatus, wherein at least a portion of the bottom surface of the process top cover has a surface roughness of 3 μm ~ 15 μm. By increasing the surface roughness of the bottom surface of the process top cover, the binding force between the deposits and the process top cover can be effectively increased, thereby inhibiting the falling of the deposits during the wafer growth process. If the roughness of the bottom surface of the process top cover is too small (e.g., less than 3 μm), the binding force between the deposits and the process top cover cannot be effectively increased. If the roughness of the bottom surface of the process top cover is too large (e.g., greater than 15 μm), the flow of the process gas during the wafer growth process can be adversely affected, thereby affecting the quality of the thin film growth on the wafer. In some embodiments, at least a portion of the bottom surface of the process top cover has a surface roughness of 5 μm ~ 10 μm.

[0050] As Figure 2 and Figure 3As shown, the utility model provides a kind of process top cover 204 for in gas phase deposition equipment, the process top cover 204 is arranged in the reaction cavity of gas phase deposition equipment, the process top cover 204 includes substrate 241, the substrate 241 has annular structure, can be made of graphite.It is coated with corrosion-resistant coating 244 on the upper surface 242 (i.e. the surface towards the cavity top cover 211) of the substrate 241, and the corrosion-resistant coating 244 covers all upper surface of the substrate 241 in the embodiment;The surface roughness Ra of the roughened surface of all lower surface 243 (i.e. all surface towards the tray 202) of the substrate 241 is 3 μm ~15 μm.This embodiment can effectively increase the binding force between the lower surface of process top cover 204 and adherent by increasing the surface roughness Ra of the lower surface 243 of substrate 241 to 3 μm ~15 μm, inhibit adherent to fall on wafer W, to improve thin film growth quality further.In another embodiment, the surface roughness Ra of the roughened surface of all lower surface 243 of the substrate 241 is 5 μm ~10 μm.

[0051] Wherein, the corrosion-resistant coating 244 is pyrolytic carbon coating, it has the characteristics of high temperature resistance, corrosion resistance, not only can improve the stability of substrate 241 under high temperature, can effectively prevent substrate 241 from being corroded, prolong the service life of substrate 241.In other embodiments, the corrosion-resistant coating 244 can also be silicon carbide (SiC) coating and other coatings.

[0052] In another embodiment, as Figure 4As shown, the lower surface 243 of the substrate 241 comprises a first region 243a and a second region 243b, the second region 243b is located at the outer edge of the substrate 241 and is arranged around the first region 243a; wherein the first region 243a is a roughened region, and the second region 243b is a non-roughened region, that is, the surface roughness of the first region 243a is greater than that of the second region 243b, and the surface roughness Ra of the first region 243a after roughening is 3 μm ~ 15 μm. In another embodiment, the surface roughness Ra of the first region 243a after roughening is 5 μm ~ 10 μm. This is because the first region 243a is located above the wafer and covers the reaction area of the wafer, causing the first region 243a to be prone to forming attachments, so by increasing its surface roughness, the adhesion between the first region 243a and the attachments can be effectively increased, reducing the risk of attachments falling. The second region 243b is located at the edge of the process top cover 204 and is supported by a support below, and the support can at least partially shield the second region 243b, so that the attachments generated in the second region 243b are less, and thus the second region 243 does not need to be roughened. The ratio of the radial width d2 of the second region 243b of the lower surface of the substrate 241 to the radial width d1 of the substrate 241 ranges from 5% to 15% to avoid the area of the second region 243b being too large and increasing the risk of attachments falling.

[0053] In yet another embodiment, as shown in Figure 5 The second region 243b of the lower surface of the substrate 241 is covered with a corrosion-resistant coating 244.

[0054] In yet another embodiment, as shown in Figure 6 The upper surface 242 of the substrate 241 is covered with a first corrosion-resistant coating 244a, and the lower surface 243 of the substrate 241 is covered with a second corrosion-resistant coating 244b, and the surface roughness Ra of the second corrosion-resistant coating 244b is 3 μm ~ 15 μm. By increasing the surface roughness Ra of the second corrosion-resistant coating 244b to 3 μm ~ 15 μm, the adhesion between the second corrosion-resistant coating 244b and the attachments can be effectively increased, reducing the risk of attachments falling and improving product yield. In other embodiments, the surface roughness Ra of the second corrosion-resistant coating 244b is 5 μm ~ 10 μm.

[0055] In addition, when the corrosion-resistant coating is covered on the surface of the substrate of the process top cover, the corrosion-resistant coating on the surface of the substrate may fall off from the substrate when the number of process cycles (i.e. Run number) is low, affecting the growth quality of the film on the wafer.

[0056] Therefore further, in order to reduce the corrosion-resistant coating from the substrate surface off the case, the utility model discloses the roughening treatment is carried out to the substrate surface and then coats the corrosion-resistant coating, thereby increasing the bonding force of corrosion-resistant coating and substrate, reduce the corrosion-resistant coating from the substrate surface off the case.

[0057] In the embodiment as shown in the figure, Figure 2 And Figure 3 The upper surface of the substrate 241 is roughened, the surface roughness Ra of the upper surface of the substrate 241 is increased, and then the corrosion-resistant coating 244 is coated, the bonding force of the corrosion-resistant coating 244 and the substrate 241 is increased, and the falling of the corrosion-resistant coating 244 is reduced.

[0058] In the embodiment, the upper surface of the substrate 241 without roughening treatment has a first surface roughness Ra, and the upper surface of the substrate 241 after roughening treatment has a second surface roughness Ra, the second surface roughness Ra is 2 to 50 times of the first surface roughness Ra. Through experimental test, when the surface roughness of the upper surface 242 of the substrate 241 is increased to 2 to 50 times of the original surface roughness of the substrate 241, the corrosion-resistant coating 244 does not fall off from the upper surface of the substrate 241 during wafer growth. As an optional embodiment, the second surface roughness Ra is 0.5 μm~5 μm, and the surface roughness Ra of the corrosion-resistant coating 244 after coating the corrosion-resistant coating 244 is 0.5 μm~5 μm.

[0059] Further, as shown in the figure, Figure 3 The thickness of the corrosion-resistant coating 244 is 20 μm~50 μm. When the surface roughness of the upper surface of the substrate 241 is increased and the thickness of the corrosion-resistant coating 244 is less than 20 μm, the coating thickness of the substrate 241 is too thin to be easily damaged, thereby affecting the effect of preventing the substrate 241 from being corroded. When the thickness of the corrosion-resistant coating 244 is greater than 50 μm, the internal stress of the corrosion-resistant coating 244 is too large, which increases the risk of cracking of the corrosion-resistant coating 244.

[0060] Similarly, in the embodiment as shown in the figure, Figure 5 The surface roughness Ra of the upper surface 242 and the second region 243b of the lower surface of the substrate 241 is 0.5 μm~5 μm.

[0061] In the embodiment as shown in the figure, Figure 6In the shown embodiment, the surface roughness Ra of the upper surface and the lower surface of the substrate 241 is 3-15 μm. In this embodiment, the surface roughness Ra of the upper surface and the lower surface of the substrate 241 is increased, and then the first corrosion-resistant coating 244a and the second corrosion-resistant coating 244b are coated respectively, so that the bonding force between the first corrosion-resistant coating 244a, the second corrosion-resistant coating 244b and the substrate 241 is increased, thereby reducing the falling of the first corrosion-resistant coating 244a and the second corrosion-resistant coating 244b from the process top cover 204, reducing the corrosion of the process gas to the process top cover 204, prolonging the service life, thereby reducing the frequency of replacing the process top cover 204, and effectively improving the production efficiency. In this embodiment, the surface roughness Ra of the first corrosion-resistant coating 244a and the second corrosion-resistant coating 244b is 3-15 μm.

[0062] In other embodiments, the surface roughness Ra of the upper surface and the lower surface of the substrate 241 is 5-10 μm. In these embodiments, the surface roughness Ra of the first corrosion-resistant coating 244a and the second corrosion-resistant coating 244b is 5-10 μm.

[0063] Further, in other embodiments, in the process top cover as shown in Figure 6 In the shown process top cover, the surface roughness Ra of the upper surface 242 of the substrate 241 is 0.5-5 μm, and the surface roughness Ra of the first corrosion-resistant coating 244a is 0.5-5 μm, so that the falling of the first corrosion-resistant coating 244a from the upper surface of the substrate 241 is effectively reduced.

[0064] In any of the above embodiments, the roughening treatment can increase the surface roughness of the substrate by any process such as sandblasting, grinding or plasma treatment. Since the sandblasting process has the advantages of good roughness consistency, simple processing and high adjustability, the sandblasting process is the preferred embodiment of the present application.

[0065] Correspondingly, the embodiment of the present application also provides a vapor deposition equipment 200, as shown in Figure 7 The vapor deposition equipment 200 comprises a reaction cavity 201. The reaction cavity 201 comprises a cavity top cover 211 and a cavity body 212. The reaction cavity 201 is provided with a tray 202, a gas inlet mechanism 203 and the process top cover 204 of any of the above embodiments, the process top cover 204 is located below the cavity top cover 211 and surrounds the gas inlet mechanism 203. This embodiment takes the process top cover 204 as shown in Figure 3 as an example for specific description.

[0066] AsFigure 7 As shown, the tray 202 is positioned below the reaction chamber 201. The upper surface of the tray 202 serves as a wafer support surface 221 for supporting one or more wafers. The lower surface of the process cover 204 (i.e., the lower surface 243 of the substrate 241) faces the wafer support surface 221, forming a reaction zone between the lower surface of the process cover 204 and the wafer support surface 221. A heating device 230 is positioned below the tray 202. Heat energy from the heating device 230 is transferred to the wafers via the tray 202. Process gases react at a specific temperature and deposit on the wafers, forming a thin film of the desired material. Furthermore, an exhaust ring 250 is positioned along the inner sidewall of the chamber body 212. The exhaust ring 250 is connected to an exhaust mechanism (not shown) to discharge waste gases generated by the reaction and any process gases that have not yet reacted out of the reaction chamber 201.

[0067] like Figure 7 As shown, the gas inlet mechanism 203 is fixed to the center of the chamber cover 211 and is used to deliver the process gas into the reaction chamber 201. In this embodiment, the gas inlet mechanism 203 is a showerhead that supplies the reaction gas horizontally; in other embodiments, the gas inlet mechanism 203 can adopt any other showerhead structure or other gas inlet structure known in the art. A support ring 231 is provided around the bottom of the chamber cover 211 to support the process cover 204.

[0068] Further, if Figure 3 and Figure 7 As shown, a step 245 is provided on the side of the process top cover 204 close to the air intake mechanism 203, and the shape of the step 245 matches the shape of the circumferential edge of the support ring 231, so that the process top cover 204 can be overlapped on the support ring 231. A support member 260 is provided below the side of the process top cover 204 away from the air intake mechanism 203, and the top end of the support member 260 supports the process top cover 204, and the bottom end rests on the exhaust ring 250 to support the process top cover 204.

[0069] like Figure 7As shown, the cavity top cover 211 and the process top cover 204 are further provided with a temperature regulating plate 206, the temperature regulating plate 206 is fixedly connected with the cavity top cover 211, and there is a gap between the temperature regulating plate 206 and the process top cover 204, which serves as a flow channel of purge gas to realize temperature regulation of the process top cover 204. The purge gas enters from the gas inlet channel 213 on the cavity top cover 211, and then enters the gap between the temperature regulating plate 206 and the process top cover 204 through the gas inlet hole 261 on the temperature regulating plate 206. In some embodiments, the purge gas can be one of hydrogen, nitrogen and argon or a mixed gas formed by the above gases. By changing the composition and flow rate of the purge gas, the temperature of the process top cover 204 can be adjusted. After the purge gas flows out of the gap, it is discharged from the reaction chamber 201 through the gas exhaust ring 250. The minimum vertical height of the gap between the lower surface of the temperature regulating plate 206 and the upper surface of the process top cover 204 is not more than 2 mm, so as to avoid that the gap is too large to cause failure of the temperature regulation function.

[0070] Further, since the gap is used to regulate the temperature of the process top cover 204, and the flatness of the upper surface of the process top cover 204 affects the vertical height of the gap, thereby affecting the temperature regulation accuracy of the process top cover 204. In the embodiment, in order to improve the temperature regulation accuracy of the process top cover 204 by the gap, the ratio of the flatness of the upper surface of the process top cover 204 to the minimum vertical height of the gap is less than or equal to 40%. That is, in the embodiment, when the flatness of the upper surface of the process top cover 204 is less than 0.8 mm, the gap can better realize effective temperature control of the process top cover 204, thereby improving the temperature distribution uniformity of the reaction area in the reaction chamber 201 and improving the product yield. In another embodiment, the flatness of the upper surface of the process top cover 204 is less than 0.5 mm. In yet another embodiment, the flatness of the lower surface of the process top cover 204 is also less than 0.8 mm, and more preferably, the flatness of the lower surface of the process top cover 204 is less than 0.5 mm, thereby improving the temperature distribution uniformity of the reaction area in the reaction chamber 201.

[0071] In summary, the process top cover and the vapor deposition equipment provided by the utility model increase the surface roughness of the lower surface of the process top cover to 3 μm ~ 15 μm, increase the adhesion between the lower surface of the process top cover and the adhering matter, and thereby inhibit the falling of the adhering matter during wafer growth. Further, by increasing the surface roughness of the substrate and then coating the corrosion-resistant coating, the adhesion between the corrosion-resistant coating and the surface of the substrate is increased, the corrosion-resistant coating is less likely to fall off from the process top cover, and the quality of wafer film growth is further improved.

[0072] The proportion of the planeness of the upper surface of the process top cover to the minimum vertical height of the gap in the gas deposition device is set within 40%, which can improve the temperature regulation accuracy of the process top cover, and further improve the temperature distribution uniformity in the reaction cavity, and improve the product yield.

[0073] It should be noted that in this document, the terms "comprise", "comprising", or any other variant thereof are intended to cover non-exclusive inclusions, so that processes, methods, articles or devices that include a series of elements not only include those elements, but also include other elements not explicitly listed, or include elements inherent to such processes, methods, articles or devices. Without more limitations, the element defined by the statement "comprises a" does not exclude the presence of another identical element in the process, method, article or device that includes the element.

[0074] In the description of the utility model, it is understood that the orientation or positional relationship indicated by the terms "center", "height", "thickness", "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model. In the description of the utility model, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0075] In the description of the utility model, unless otherwise specified and limited, the terms "mounting", "connection", "connection", "fixing" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication between two elements or the interaction relationship between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0076] In the utility model, unless another definite provision and limitation, first feature is "on" or "under" second feature can include that first and second features are in direct contact, also can include that first and second features are not in direct contact but contact through other feature between them.

[0077] Although the content of the utility model has been introduced in detail through the above preferred embodiment, it should be recognized that the above description should not be considered as the limitation of the utility model. After the above content is read by the person skilled in the art, various modifications and substitutions of the utility model will be obvious. Therefore, the protection scope of the utility model should be limited by the attached claim.

Claims

1. A process top cover for a vapor deposition apparatus, characterized by, Comprising: a substrate having a ring shape; a corrosion-resistant coating layer covering an upper surface of the substrate; a surface roughness of at least a part of a lower surface of the process top cover is 3 μm ~ 15 μm.

2. The process head of claim 1, wherein, a surface roughness of at least a part of a lower surface of the process top cover is 5 μm ~ 10 μm.

3. Process head according to claim 1 or 2, characterized in that a lower surface of the process top cover is a lower surface of the substrate.

4. The process head of claim 1, wherein, the corrosion-resistant coating layer covering the upper surface of the substrate is a first corrosion-resistant coating layer, a lower surface of the substrate is covered with a second corrosion-resistant coating layer, and a lower surface of the process top cover is a lower surface of the second corrosion-resistant coating layer.

5. The process head of claim 1, wherein, a lower surface of the substrate comprises a first region and a second region, the second region is located at an outer edge of the substrate and is arranged around the first region; wherein a surface roughness of the first region is greater than a surface roughness of the second region, and the surface roughness of the first region is 3 μm ~ 15 μm.

6. The process head of claim 5, wherein, a surface roughness of the first region is 5 μm ~ 10 μm.

7. The process head of claim 5, wherein, the second region is covered with a corrosion-resistant coating layer.

8. The process head of claim 7, wherein, a surface roughness of the second region is 0.5 μm ~ 5 μm.

9. A process head as claimed in any of claims 5 to 8, characterized in that a ratio of a radial width of the second region of the lower surface of the substrate to a radial width of the substrate ranges from 5% to 15%.

10. The process head of claim 1, wherein, an upper surface of the substrate without roughening treatment has a first surface roughness, and an upper surface of the substrate after roughening treatment has a second surface roughness, the second surface roughness being 2 to 50 times of the first surface roughness.

11. The process head of claim 1, wherein, a surface roughness of an upper surface of the substrate is 0.5 μm ~ 5 μm.

12. The process head of claim 1, wherein, a thickness of the corrosion-resistant coating layer ranges from 20 μm to 50 μm.

13. The process head of claim 1, wherein, a surface roughness of the corrosion-resistant coating layer is 0.5 μm ~ 5 μm.

14. The process head of claim 4, wherein, a surface roughness of the first corrosion-resistant coating layer and the second corrosion-resistant coating layer is 3 μm ~ 15 μm.

15. The process head of claim 14, wherein, a surface roughness of the first corrosion-resistant coating layer and the second corrosion-resistant coating layer is 5 μm ~ 10 μm.

16. The process head of claim 14, wherein, a surface roughness of the upper surface and the lower surface of the substrate is 3 μm ~ 15 μm.

17. The process head of claim 15, wherein, a surface roughness of the upper surface and the lower surface of the substrate is 5 μm ~ 10 μm.

18. The process head of claim 4, wherein, a surface roughness of the upper surface of the substrate is 0.5 μm ~ 5 μm, and a surface roughness of the first corrosion-resistant coating layer is 0.5 μm ~ 5 μm.

19. The process head of claim 1, wherein, a flatness of an upper surface of the process top cover is below 0.8 mm, or a flatness of both the upper surface and the lower surface of the process top cover is below 0.8 mm.

20. The process head of claim 1, wherein, a flatness of an upper surface of the process top cover is below 0.5 mm, or a flatness of both the upper surface and the lower surface of the process top cover is below 0.5 mm.

21. The process head of claim 1, wherein, the corrosion-resistant coating layer comprises a pyrolytic carbon coating layer, and the substrate is made of graphite.

22. A vapour deposition apparatus, characterised in that, Comprising: a reaction cavity; a gas inlet mechanism arranged at a top of the reaction cavity for delivering gas into the reaction cavity; a tray arranged in the reaction cavity for carrying a wafer; a process top cover as claimed in any one of claims 1 to 21 is arranged below a cavity top cover of the reaction cavity and surrounds the gas inlet mechanism.

23. A vapour deposition apparatus as claimed in claim 22, wherein Further comprising: A temperature control plate is arranged between the cavity top cover and the process top cover, and a gap exists between the process top cover.

24. A vapour deposition apparatus as claimed in claim 23, wherein, The ratio of the flatness of the upper surface of the process top cover to the minimum vertical height of the gap is less than or equal to 40%.

25. A vapour deposition apparatus as claimed in claim 23, wherein The minimum vertical height of the gap between the lower surface of the temperature control plate and the upper surface of the process top cover is not more than 2 mm.

26. A vapour deposition apparatus as claimed in claim 22, wherein The bottom of the cavity top cover is circumferentially provided with a support ring, and the process top cover is provided with a step near one side of the air inlet mechanism for lapping on the support ring.

27. A vapour deposition apparatus as claimed in claim 22, wherein The lower surface of the substrate comprises a first region and a second region, the second region is located at the outer edge of the substrate and is arranged around the first region; wherein the surface roughness of the first region is greater than that of the second region, the surface roughness of the first region is 3-15 μm, and the first region covers the wafer on the tray.

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