Gas spray header assembly and plasma processing device

Abstract

The utility model discloses a gas spray header assembly and a plasma processing device, the gas spray header assembly is arranged in a reaction cavity of the plasma processing device, and the gas spray header assembly comprises a back plate located at the top in the reaction cavity; the gas spraying head is positioned below the back plate; the first end of the suspension device is connected with the back plate, and the second end of the suspension device is connected with the gas spraying head; the gas spraying head is provided with an arched upper surface and an arched lower surface, and the central area of the upper surface of the gas spraying head is lower than the edge area; the central area of the lower surface of the gas spraying head is higher than the edge area, and the height difference between the central area and the edge area of the upper surface of the gas spraying head is larger than that between the central area and the edge area of the lower surface of the gas spraying head; according to the gas spray header assembly, the lower surface of the gas spray header is approximately parallel to the upper surface of the base in a high-temperature process environment, so that the distribution uniformity of plasmas below the gas spray header is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of semiconductor processing, concretely relates to a gas shower head assembly and plasma processing device. BACKGROUND

[0002] Plasma enhanced chemical vapor deposition (PECVD) is a large area thin film deposition device, which is usually used for depositing thin films on glass substrates, such as semiconductor substrates, solar panel substrates, and liquid crystal displays (LCD) and organic light emitting diodes (OLED) used for display manufacturing, etc. PECVD provides process gas above a susceptor through a gas shower head assembly, wherein the gas shower head is generally made of aluminum or aluminum alloy, and the edge of the gas shower head is usually connected with a reaction chamber through a suspension mechanism. However, during the process, due to the high temperature in the reaction chamber, the gas shower head is inevitably affected by the high temperature and gradually deformed, so that the plasma originally uniformly distributed below the gas shower head becomes unevenly distributed due to the deformation of the gas shower head, which affects the process treatment effect of the substrate.

[0003] The statements herein only provide background technology related to the utility model, and do not necessarily constitute prior art. SUMMARY

[0004] The utility model aims at providing a gas shower head assembly and plasma processing device, so that the lower surface of the gas shower head is approximately parallel to the upper surface of the susceptor in a high temperature process environment, thereby ensuring the uniformity of the plasma distribution in the reaction chamber.

[0005] To achieve the above-mentioned purpose, the utility model provides a gas shower head assembly arranged in the reaction chamber of a plasma processing device, comprising:

[0006] a back plate, which is located at the top of the reaction chamber;

[0007] a gas shower head, which is located below the back plate;

[0008] a suspension device, the first end of which is connected with the back plate, and the second end of which is connected with the gas shower head;

[0009] The gas shower head has an arched upper surface and a lower surface, the center area of the upper surface of the gas shower head is lower than the edge area, and the center area of the lower surface of the gas shower head is higher than the edge area; the height difference between the center area and the edge area of the upper surface of the gas shower head is greater than the height difference between the center area and the edge area of the lower surface of the gas shower head.

[0010] Optionally, the gas shower head assembly comprises a first connecting device, which is arranged between the back plate and the gas shower head, and connects the upper surfaces of the back plate and the gas shower head.

[0011] Optionally, the first connecting device is a plurality of screws.

[0012] Optionally, the number of turns of the screws screwed into the gas shower head is set to provide a corresponding size of pre-tightening force to the gas shower head.

[0013] Optionally, the gas shower head assembly further comprises an air inlet mechanism, the air inlet mechanism penetrates the back plate, and the plurality of screws are arranged around the air inlet mechanism.

[0014] Optionally, the number of screws is 12.

[0015] Optionally, the screws are made of hastelloy.

[0016] Optionally, the surface of the screw is coated with a corrosion-resistant layer.

[0017] Optionally, the first end of the suspension device is connected to the lower surface of the back plate, and the second end of the suspension device is connected to the edge of the gas shower head.

[0018] Optionally, the side wall of the reaction chamber has a protruding portion protruding inward of the reaction chamber, the lower surface of the back plate is in contact with the upper surface of the protruding portion, and the gas shower head is located inward of the protruding portion.

[0019] Optionally, the gas shower head assembly further comprises an insulation device, which is arranged between the back plate and the upper surface of the protruding portion, and arranged between the gas shower head and the side wall of the protruding portion.

[0020] Optionally, the gas shower head assembly further comprises a sealing structure, which is arranged between the insulation device and the back plate, and arranged between the insulation device and the upper surface of the protruding portion.

[0021] Optionally, a mounting bracket is arranged above the back plate, and the mounting bracket and the back plate are connected and fixed by a second connecting device.

[0022] Optionally, the second connecting device is made of hastelloy.

[0023] The utility model further provides a kind of plasma processing device, comprising:

[0024] Reaction chamber;

[0025] Gas shower head assembly is arranged at the top of the reaction chamber, and the gas shower head assembly transports process gas into the reaction chamber.

[0026] a base disposed in the reaction cavity and opposite to the gas shower head assembly, the base being configured to support a substrate to be processed;

[0027] a mounting bracket disposed above the reaction cavity, the mounting bracket being connected to the back plate of the gas shower head assembly, and the mounting bracket providing an upward pulling force to the back plate through the second connecting device.

[0028] Compared with the prior art, the technical scheme of the utility model has at least the following advantages and beneficial effects:

[0029] The gas shower head assembly comprises a back plate and a gas shower head located below the back plate, the gas shower head has an arched upper surface and a lower surface, the center area of the upper surface of the gas shower head is lower than the edge area, the center area of the lower surface of the gas shower head is higher than the edge area, the height difference between the center area and the edge area of the upper surface of the gas shower head is greater than the height difference between the center area and the edge area of the lower surface of the gas shower head, so that the gas shower head is more inclined to the lower surface when thermal deformation occurs in the vertical direction under a high-temperature process environment, and the lower surface of the gas shower head is substantially parallel to the upper surface of the base under the high-temperature process environment, so that the uniformity of plasma distribution below the gas shower head is ensured.

[0030] In the utility model, the height difference between the center area and the edge area of the upper surface of the gas shower head is greater than the height difference between the center area and the edge area of the lower surface of the gas shower head, and the gas shower head assembly is connected to the back plate through a plurality of screws as the first connecting device, so that the pre-tightening force applied to the first connecting device during installation of the gas shower head can be maintained under a high-temperature process environment, and the reliability of the first connecting device supporting the gas shower head is improved.

[0031] The gas shower head assembly of the utility model comprises an insulation device, which ensures the insulation between the back plate, the gas shower head and the side wall of the reaction cavity, and further comprises a sealing device, which prevents process gas from leaking and ensures the sealing property of the reaction cavity. BRIEF DESCRIPTION OF DRAWINGS

[0032] Fig. 1 It is a structural schematic view of a plasma processing device of the utility model;

[0033] Fig. 2 It is a partial schematic view of a plasma processing device of the utility model;

[0034] Fig. 3 It is a structural schematic view of a gas shower head of the utility model.

[0035] BRIEF DESCRIPTION OF DRAWINGS:

[0036] Reaction cavity 100, side wall 130, substrate 140, base 150, bottom wall 160, back plate 121, gas inlet mechanism 122, first screw 123, gas shower head 124, groove 1241, gas channel 1242, second screw 125, suspension device 126, insulation device 127, first insulation baffle 1271, second insulation baffle 1272, third insulation baffle 1273, first sealing structure 129, second sealing structure 128 DETAILED DESCRIPTION

[0037] The technical solutions, structural features, purposes achieved and effects of the embodiments of the present application will be described in detail below. Figs. 1-3 The technical solutions, structural features, purposes achieved and effects of the embodiments of the present application will be described in detail below.

[0038] It should be noted that the drawings are very simplified and use non-precise proportions, only to facilitate and clarify the purpose of assisting the description of the embodiments of the present application, and are not used to limit the conditions of the embodiments of the present application, so they do not have substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present application, should still fall within the scope of the technical content disclosed by the present application.

[0039] It should be noted that in the present application, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes the explicitly listed elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment.

[0040] In the reaction cavity of the plasma processing device, the gas shower head is arranged at the top of the reaction cavity and opposite to the base carrying the substrate. The gas shower head is also connected with the external gas supply device to provide process gas above the base. During the process, due to the high process temperature in the reaction cavity, the gas shower head inevitably deforms due to high temperature, especially for the reaction cavity in the field of flat panel display, the area of the gas shower head is larger, and the thermal deformation is more obvious. After the deformation of the gas shower head, the uniformity of the plasma distribution below the gas shower head is affected, thereby affecting the processing effect of the substrate.

[0041] In order to solve the above problems, the utility model provides a kind of gas shower head assembly and plasma processing device, gas shower head assembly is arranged in the reaction cavity of plasma processing device, including backplate and gas shower head, adopt suspension device to connect backplate and gas shower head, the height difference between the central region and the edge region of the upper surface of the gas shower head is greater than the height difference between the central region and the edge region of the lower surface of the gas shower head.

[0042] The technical solutions of the embodiments of the present application will be described in detail below with reference to the drawings.

[0043] Please refer to Fig. 1 The utility model provides a kind of plasma processing device including reaction cavity 100, reaction cavity 100 is enclosed by side wall 130, the bottom of the reaction cavity 100 also has bottom wall 160, the bottom in reaction cavity 100 is equipped with pedestal 150, this pedestal 150 is used to carry the wafer 140 to be handled, the top in reaction cavity 100 is equipped with gas shower head assembly, gas shower head assembly is oppositely arranged with pedestal 150.Gas shower head assembly is connected with the gas supply device outside, and process gas is transported to the inside of reaction cavity 100.

[0044] Please refer to Fig. 2 The gas shower head assembly includes backplate 121 and gas shower head 124, backplate 121 is located at the top in the reaction cavity 100, gas shower head 124 is arranged below the backplate 121, is connected with backplate 121 by suspension device 126.Suspension device 126 is connected with the backplate 121 at first end, and the second end of suspension device 126 is connected with the edge of gas shower head 124, and the main weight of gas shower head 124 is borne by backplate 121 through the suspension device 126.The first end of suspension device 126 is connected with the backplate 121, and is connected and fixed by second screw 125, and the second end of suspension device 126 is connected with the edge of gas shower head 124.In some embodiments, the side wall of gas shower head 124 is provided with recess 1241, and second screw 125 connects the second end of suspension device 126 with the recess 1241 of gas shower head 124, so that the edge of gas shower head 124 is fixedly connected below backplate 121 by suspension device 126.The suspension device 126 can be multiple arcs, is circumferentially spaced apart along the outer wall of gas shower head 124, and the shape of each suspension device 126 is matched with the outer wall of gas shower head 124, and in other embodiments, the suspension device 126 can also be a complete frame type, is circumferentially arranged along the outer wall of gas shower head 124, and the shape is matched with the outer wall of gas shower head 124.

[0045] The gas shower head assembly further comprises a gas inlet mechanism 122, which is arranged in the central region of the back plate 121 and penetrates the back plate 121 from top to bottom. A gas diffusion cavity is formed between the lower surface of the back plate 121 and the upper surface of the gas shower head 124, and the gas inlet mechanism 122 inputs the process gas into the gas diffusion cavity.

[0046] Please refer to Fig. 3 The gas shower head 124 has a plurality of gas passages 1242 penetrating from top to bottom, so that the process gas entering the gas diffusion cavity through the gas inlet mechanism 122 can uniformly enter the reaction chamber 100 through the gas passages 1242.

[0047] Please refer to Fig. 1 The first connecting device is arranged in the central region of the gas shower head 124. In the embodiment, a plurality of first screws 123 are used as the first connecting device, each of which penetrates the back plate 121 from top to bottom and is screwed into the gas shower head 124 from top to bottom, thereby connecting the back plate 121 and the gas shower head 124 and providing the upward pulling force for the gas shower head 124.

[0048] The plurality of first screws 123 are arranged around the gas inlet mechanism 122. In the embodiment, the number of the first screws 123 is 12. The first screws 123 are made of hastelloy, which has excellent strength, hardness and thermal stability and is not easy to be deformed by high temperature, thereby avoiding the position change of the gas shower head 124 caused by the expansion of the first screws 123, and the use of hastelloy also ensures the stability of the connection between the first screws 123 and the gas shower head 124.

[0049] Since part of the first screws 123 is located in the gas diffusion cavity and exposed to the process gas environment, in order to prevent the corrosive process gas from damaging the first screws 123, a corrosion-resistant layer can also be coated on the surface of the first screws 123.

[0050] In order to ensure the uniformity of the plasma distribution in the chamber, it is usually required that the upper and lower electrodes are parallel to each other, i.e. the lower surface of the gas showerhead and the upper surface of the susceptor are parallel to each other. However, in the process, in order to ensure the film formation rate and the film quality, it is usually required to carry out the reaction at a relatively high process temperature, and the gas showerhead is usually made of aluminum or aluminum alloy material, which has a large thermal deformation after being heated, resulting in that the lower surface of the gas showerhead is deformed by heat at a high temperature process, so that the originally parallel state cannot be maintained, which affects the uniformity of the plasma distribution. Therefore, the gas showerhead 124 described in the present application has an arched upper surface and a lower surface (in Fig. 3 In the present application, since the gas showerhead 124 is long in the horizontal direction, dotted lines are used at both ends to omit the drawing), the upper surface of the gas showerhead 124 is a downwardly concave arch, and the central region is lower than the edge region, and the lower surface of the gas showerhead 124 is an upwardly concave arch, and the central region is higher than the edge region. The height difference between the central region and the edge region of the upper surface of the gas showerhead 124 is H1, and the height difference between the central region and the edge region of the lower surface of the gas showerhead 124 is H2, and H1 is greater than H2.

[0051] The principle of setting the arched relationship between the upper and lower surfaces of the gas shower head 124 and the first screw 123 supporting the gas shower head 124 is described as follows. The gas shower head 124 is machined so that the height difference between the central region and the edge region of the upper surface is H1, the height difference between the central region and the edge region of the lower surface is H2, and H1 is greater than H2. When the gas shower head 124 is assembled into the reaction chamber 200, the gas shower head 124 is connected with the back plate 121 through the suspension device 126 and the first screw 123, the first screw 123 is screwed into the gas shower head 124 for a predetermined number of turns to complete the assembly of the reaction chamber 100. However, during the process, the reaction chamber 100 is at a process temperature (usually a high temperature of 300 degrees or higher), the suspension device 126 is made of rigid material, and the gas shower head 124 is limited in the horizontal direction by the suspension device 126, so the gas shower head 124 deforms more in the vertical direction. If the height difference H1 between the central region and the edge region of the upper surface of the gas shower head 124 is less than the height difference H2 between the central region and the edge region of the lower surface of the gas shower head 124, the gas shower head 124 will deform more towards its upper surface, which cannot guarantee the parallel relationship between the lower surface of the gas shower head 124 and the upper surface of the pedestal 150. If the height difference H1 between the central region and the edge region of the upper surface of the gas shower head 124 is equal to the height difference H2 between the central region and the edge region of the lower surface of the gas shower head 124, the machining error caused by machining may cause uncertainty in the direction of thermal deformation of the gas shower head 124. Therefore, in this application, the height difference H1 between the central region and the edge region of the upper surface of the gas shower head 124 is greater than the height difference H2 between the central region and the edge region of the lower surface of the gas shower head 124. This setting makes the gas shower head 124 deform more towards the lower surface with a smaller arch in the high-temperature process environment, so that the lower surface of the gas shower head 124 is approximately parallel to the upper surface of the pedestal 150, thereby ensuring the uniformity of plasma distribution in the high-temperature process environment. At the same time, the first screw 123 screwed into the gas shower head 124 for a predetermined number of turns can also provide an upward pulling force to the gas shower head 124 in the high-temperature process, thereby ensuring reliable support for the gas shower head 124. Optionally, the height difference H2 between the central region and the edge region of the lower surface of the gas shower head 124 is in the range of 0-2.5 mm to adapt to different process requirements.

[0052] Further, by uniformly arranging a plurality of first screws 123 around the gas inlet mechanism 122, a uniform and symmetrical upward pulling force is provided to the gas shower head 124, so that the shape of the lower surface of the gas shower head 124 is basically symmetrical even in the high-temperature process condition, thereby achieving more uniform plasma distribution.

[0053] Further, the number of turns of the first screw 123 into the gas shower head 124 is set to provide different pre-tightening forces to the gas shower head 124, so as to adapt to different parameters of the reaction chamber 100. The more turns of the first screw 123 into the gas shower head 124, the greater the pre-tightening force provided by the first screw 123 to the gas shower head 124. The number of turns of the first screw 123 into the gas shower head 124 can be adjusted according to actual process requirements.

[0054] Please continue to refer to Fig. 1 and Fig. 2 The side wall 130 of the reaction chamber 100 has a protruding portion 131 protruding inwardly into the reaction chamber 100. The protruding portion 131 is integrally formed with the side wall 130, and is arranged on the inner wall of the side wall 130 and protrudes in the horizontal direction. The back plate 121 falls on the protruding portion 131, the lower surface of the back plate 121 is in contact with the upper surface of the protruding portion 131, and the gas shower head 124 is located on the inner side of the protruding portion 131.

[0055] In addition, since the radio frequency power is fed into the reaction chamber through the gas shower head assembly, the gas shower head assembly further comprises an insulation device 127, which comprises a first insulation baffle 1271 arranged between the back plate 121 and the side wall 130, a second insulation baffle 1272 arranged between the back plate 121 and the upper surface of the protruding portion 131, and a third insulation baffle 1273 arranged between the gas shower head 124 and the side wall of the protruding portion 131. The insulation baffles are all made of insulating materials. The first insulation baffle 1271 is arranged in the vertical direction, so as to ensure the insulation between the back plate 121 and the side wall 130 on both sides of the first insulation baffle 1271. The second insulation baffle 1271 is arranged in the horizontal direction between the lower surface of the back plate 121 and the upper surface of the protruding portion 131. The third insulation baffle 1273 is L-shaped, the vertical face of which is arranged between the side wall of the protruding portion 131 and the side wall of the gas shower head 124, and the horizontal face of which is arranged on the lower surface of the protruding portion 131 and extends into the groove 1241. Through the first insulation baffle 1271, the second insulation baffle 1272 and the third insulation baffle 1273, the insulation between the back plate 121 and the side wall 130, the back plate 121 and the protruding portion 131, and the gas shower head 124 and the protruding portion 131 is ensured.

[0056] The upper side of the back plate 121 is also provided with a mounting bracket 111, which is located above the reaction cavity 100, and is connected and fixed with the back plate 121 through a second connecting device 112, so as to fix the back plate 121 on the mounting bracket 111, and the mounting bracket 111 provides an upward pulling force to the back plate 121 through the second connecting device 112, so as to bear most of the weight of the back plate 121, and the second connecting device 121 can be a plurality of screw rods 121, which are also uniformly arranged around the air inlet mechanism 122, so as to provide a symmetrical upward pulling force, and the screw rod 121 is also made of hastelloy, so as to have better hardness, strength and thermal stability.

[0057] In order to ensure the sealed environment in the reaction cavity 100, the gas spraying head assembly further comprises a sealing structure, which is arranged between the insulation device 127 and the back plate 121, and between the insulation device 127 and the protruding part 131. Specifically, the sealing structure comprises a first sealing structure 129 and a second sealing structure 128 arranged along the circumference of the back plate 121, the first sealing structure 129 is arranged between the second insulation baffle 1272 and the lower surface of the back plate 121, and the second sealing structure 128 is arranged between the second insulation baffle 1272 and the upper surface of the protruding part 131. The first sealing structure 129 and the second sealing structure 128 can be sealing rings, through which the process gas in the reaction cavity 100 is prevented from leaking from the gap between the back plate 121 and the second insulation baffle 1272, and from the gap between the second insulation baffle 1272 and the protruding part 131, so as to ensure the sealing and vacuum properties of the reaction cavity 100.

[0058] Although the content of the present application has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present application. After reading the above content, various modifications and alternatives of the present application will be obvious to those skilled in the art. Therefore, the protection scope of the present application should be defined by the appended claims.

Claims

1. A gas showerhead assembly disposed within a reaction chamber of a plasma processing apparatus, the gas showerhead assembly comprising: The gas shower head assembly comprises: a back plate, which is located at the top of the reaction chamber; a gas shower head, which is located below the back plate; a suspension device, the first end of which is connected to the back plate, and the second end of which is connected to the gas shower head; the gas shower head has an arched upper surface and a lower surface, the central region of the upper surface of the gas shower head is lower than the edge region, and the central region of the lower surface of the gas shower head is higher than the edge region; the height difference between the central region and the edge region of the upper surface of the gas shower head is greater than the height difference between the central region and the edge region of the lower surface of the gas shower head.

2. The gas showerhead assembly of claim 1, wherein, The gas shower head assembly further comprises a first connecting device, which connects the back plate and the upper surface of the gas shower head.

3. The gas showerhead assembly of claim 2, wherein, The first connecting device is a plurality of screws.

4. The gas showerhead assembly of claim 3, wherein, The number of turns of the screws into the gas shower head is set to provide a corresponding size of pre-tightening force to the gas shower head.

5. The gas showerhead assembly of claim 3, wherein, The gas shower head assembly further comprises an air inlet mechanism, which penetrates the back plate, and a plurality of the screws are arranged around the air inlet mechanism.

6. The gas showerhead assembly of claim 3, wherein, The number of screws is 12.

7. The gas showerhead assembly of claim 3, wherein, The screws are made of hastelloy.

8. The gas showerhead assembly of claim 5, wherein, The surface of the screws is coated with a corrosion-resistant layer.

9. The gas showerhead assembly of claim 1, wherein, The first end of the suspension device is connected to the lower surface of the back plate, and the second end of the suspension device is connected to the edge of the gas shower head.

10. The gas showerhead assembly of claim 1, wherein, The side wall of the reaction chamber has a protrusion protruding inward of the reaction chamber, the lower surface of the back plate is in contact with the upper surface of the protrusion, and the gas shower head is located inward of the protrusion.

11. The gas showerhead assembly of claim 10, wherein, The gas shower head assembly further comprises an insulation device, which is arranged between the back plate and the upper surface of the protrusion, and between the gas shower head and the side wall of the protrusion.

12. The gas showerhead assembly of claim 11, wherein, The gas shower head assembly further comprises a sealing structure, which is arranged between the insulation device and the back plate, and between the insulation device and the upper surface of the protrusion.

13. The gas showerhead assembly of claim 1, wherein, An installation bracket is arranged above the back plate, and the installation bracket and the back plate are connected and fixed by a second connecting device.

14. The gas showerhead assembly of claim 13, wherein, The second connecting device is made of hastelloy.

15. A plasma processing apparatus, characterized by comprising: The gas shower head assembly comprises: a reaction chamber; a gas shower head assembly according to any one of claims 1-14, which is arranged at the top of the reaction chamber and delivers process gas into the reaction chamber; a pedestal, which is arranged in the reaction chamber and is arranged opposite to the gas shower head assembly, and is used to carry a substrate to be processed; an installation bracket, which is arranged above the reaction chamber, is connected to the back plate in the gas shower head assembly, and provides an upward pulling force to the back plate through a second connecting device.

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