Gas spray header assembly and plasma processing device

Abstract

The invention 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; 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 first connecting device is connected with the back plate and the upper surface of 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 invention relates to the field of semiconductor processing, and in particular to a gas shower head assembly and a plasma processing device. Background Art

[0002] Plasma enhanced chemical vapor deposition (PECVD) is a large-area thin film deposition device, which is usually used to deposit thin films on glass substrates, such as semiconductor substrates, solar panel substrates, and liquid crystal displays (LCDs) and organic light-emitting diodes (OLEDs) used in display manufacturing. PECVD provides process gas to the top of the base through a gas shower head assembly, where the gas shower head is generally made of aluminum or aluminum alloy, and the edge of the gas shower head is usually connected to the reaction chamber through a suspension mechanism. During the process, due to the high temperature in the reaction chamber, the gas shower head is inevitably affected by the continuous influence of high temperature and gradually deforms. As a result, the plasma that should have been evenly distributed under the gas shower head becomes unevenly distributed due to the deformation of the gas shower head, affecting the process treatment effect of the substrate.

[0003] The statements herein merely provide background art related to the present invention and do not necessarily constitute prior art. Summary of the invention

[0004] The object of the present invention is to provide a gas shower head assembly and a plasma processing device, so that the lower surface of the gas shower head is roughly parallel to the upper surface of the base under a high temperature process environment, thereby ensuring the uniformity of plasma distribution in the reaction chamber.

[0005] To achieve the above object, the present invention proposes a gas shower head assembly, which is arranged in a reaction chamber of a plasma processing device, comprising:

[0006] A back plate, the back plate being located at the top of the reaction chamber;

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

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

[0009] A first connecting device, which is disposed between the back plate and the gas shower head and connects the back plate and an upper surface of the gas shower head;

[0010] The gas shower head has an arched upper surface and a lower surface, wherein the central area of ​​the upper surface of the gas shower head is lower than the edge area, and the central area of ​​the lower surface of the gas shower 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 shower head is greater than the height difference between the central area and the edge area of ​​the lower surface of the gas shower head.

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

[0012] Optionally, a corresponding pre-tightening force is provided to the gas shower head by setting the number of turns by which the screw is screwed into the gas shower head.

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

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

[0015] Optionally, the screw is 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 protrusion protruding toward the inside of the reaction chamber, the lower surface of the back plate contacts the upper surface of the protrusion, and the gas shower head is located inside the protrusion.

[0019] Optionally, the gas shower head assembly further includes an insulating device, wherein the insulating device is disposed between the back plate and the upper surface of the protrusion, and between the gas shower head and the side wall of the protrusion.

[0020] Optionally, the gas showerhead assembly further comprises a sealing structure, wherein the sealing structure is disposed between the insulating device and the back plate, and between the insulating device and the upper surface of the protrusion.

[0021] Optionally, a mounting bracket is provided above the back plate, and the mounting bracket is connected and fixed to the back plate via a second connecting device.

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

[0023] The present invention also provides a plasma processing device, comprising:

[0024] Reaction chamber;

[0025] A gas shower head assembly is arranged at the top of the reaction chamber, and the gas shower head assembly delivers process gas into the reaction chamber;

[0026] A base is arranged in the reaction chamber and is arranged opposite to the gas shower head assembly, and the base is used to carry a substrate to be processed;

[0027] The mounting bracket is arranged above the reaction chamber, the mounting bracket is connected to the back plate in the gas shower head assembly, and the mounting bracket provides an upward pulling force to the back plate through a second connecting device.

[0028] Compared with the prior art, the technical solution of the present invention has at least the following advantages and beneficial effects:

[0029] The gas shower head assembly provided by the present invention comprises a back plate and a gas shower head located below the back plate, the gas shower head having an arched upper surface and a lower surface, the central area of ​​the upper surface of the gas shower head being lower than the edge area, the central area of ​​the lower surface of the gas shower head being higher than the edge area, the height difference between the central area and the edge area of ​​the upper surface of the gas shower head being greater than the height difference between the central area and the edge area of ​​the lower surface of the gas shower head, thereby ensuring that in a high-temperature process environment, the gas shower head is more oriented toward the lower surface when thermal deformation occurs in the vertical direction, thereby ensuring that in a high-temperature process environment, the lower surface of the gas shower head is roughly parallel to the upper surface of the base, thereby ensuring the uniformity of plasma distribution below the gas shower head.

[0030] In the present invention, the height difference between the central area and the edge area of ​​the upper surface of the gas shower head is greater than the height difference between the central area and the edge area of ​​the lower surface of the gas shower head, and the gas shower head assembly uses multiple screws as the first connecting device. The pre-tightening force applied to the first connecting device when installing the gas shower head can be maintained in a high-temperature process environment, thereby improving the reliability of the first connecting device supporting the gas shower head.

[0031] The gas shower head assembly of the present invention comprises an insulating device to ensure insulation between the back plate, the gas shower head and the side wall of the reaction chamber, and also comprises a sealing device to prevent leakage of process gas and ensure the sealing of the reaction chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of a plasma processing device of the present invention;

[0033] Figure 2 It is a partial schematic diagram of a plasma processing device of the present invention;

[0034] Figure 3 It is a schematic diagram of the structure of the gas shower head of the present invention.

[0035] Description of reference numerals:

[0036] Reaction chamber 100, side wall 130, substrate 140, base 150, bottom wall 160, back plate 121, air 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 following will be combined with the embodiments of the present invention Figure 1 to Figure 3 , the technical solutions, structural features, objectives achieved and effects in the embodiments of the present invention are described in detail.

[0038] It should be noted that the drawings are in a very simplified form and use non-precise proportions. They are only used to conveniently and clearly assist in explaining the embodiments of the present invention, and are not used to limit the conditions for the implementation of the present invention. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention.

[0039] It should be noted that, in the present invention, relational terms such as first and second, etc. 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 these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only the elements explicitly listed, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0040] In the reaction chamber of the plasma processing device, the gas shower head is arranged at the top of the reaction chamber, opposite to the base that carries the substrate. The gas shower head is also connected to an external gas supply device to provide process gas to the top of the base. During the process, since the temperature in the reaction chamber is at a relatively high process temperature, the gas shower head is inevitably affected by the high temperature and deformed. Especially for the reaction chamber in the field of flat panel displays, the area of ​​the gas shower head is larger and the deformation due to heat is more obvious. And after the gas shower head is deformed, it will affect the uniformity of the plasma distribution under the gas shower head, thereby affecting the processing effect of the substrate.

[0041] To solve the above problems, the present invention proposes a gas shower head assembly and a plasma processing device. The gas shower head assembly is arranged in a reaction chamber of the plasma processing device, and includes a back plate and a gas shower head. The back plate and the gas shower head are connected by a suspension device, and a first connecting device is arranged between the gas shower head and the back plate. The height difference between the central area and the edge area of ​​the upper surface of the gas shower head is greater than the height difference between the central area and the edge area of ​​the lower surface of the gas shower head.

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

[0043] See also Figure 1 A plasma processing device provided by the present invention includes a reaction chamber 100, which is surrounded by a side wall 130. The bottom of the reaction chamber 100 also has a bottom wall 160. A base 150 is provided at the bottom of the reaction chamber 100. The base 150 is used to carry a substrate 140 to be processed. A gas shower head assembly is provided at the top of the reaction chamber 100. The gas shower head assembly is arranged opposite to the base 150. The gas shower head assembly is connected to an external gas supply device and delivers process gas into the reaction chamber 100.

[0044] Combined with reference Figure 2 The gas shower head assembly includes a back plate 121 and a gas shower head 124. The back plate 121 is located at the top of the reaction chamber 100. The gas shower head 124 is arranged below the back plate 121 and connected to the back plate 121 through a suspension device 126. The first end of the suspension device 126 is connected to the back plate 121, and the second end of the suspension device 126 is connected to the gas shower head 124. Through the suspension device 126, the back plate 121 bears the main weight of the gas shower head 124. The first end of the suspension device 126 is connected to the back plate 121 and is connected and fixed by a second screw 125. The second end of the suspension device 126 is connected to the edge of the gas shower head 124. In some embodiments, a groove 1241 is provided on the side wall of the gas shower head 124. The second screw 125 connects the second end of the suspension device 126 to the groove 1241 of the gas shower head 124, so that the edge of the gas shower head 124 is fixedly connected to the bottom of the back plate 121 through the suspension device 126. The suspension device 126 may be in the shape of a plurality of arcs, which are arranged at intervals along the circumference of the outer wall of the gas shower head 124 , and the shape of each suspension device 126 matches the outer wall of the gas shower head 124 . In other embodiments, the suspension device 126 may also be in the shape of a complete frame, which is arranged along the circumference of the outer wall of the gas shower head 124 , and its shape matches the outer wall of the gas shower head 124 .

[0045] The gas showerhead assembly further includes an air inlet mechanism 122, which is disposed in the central area 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 showerhead 124, and the air inlet mechanism 122 inputs the process gas into the gas diffusion cavity.

[0046] See also Figure 3 The gas shower head 124 has a plurality of gas channels 1242 from top to bottom, so that the process gas entering the gas diffusion chamber through the gas inlet mechanism 122 can evenly enter the reaction chamber 100 through the gas channels 1242 .

[0047] Please continue reading Figure 1 A first connecting device is further provided between the back plate 121 and the gas shower head 124, and the first connecting device connects the back plate 121 and the upper surface of the gas shower head 124, and assists in providing an upward pulling force to the gas shower head 124. Preferably, the first connecting device is arranged in the central area of ​​the gas shower head 124. In this embodiment, a plurality of first screws 123 are used as the first connecting device, and each first screw 123 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 an upward pulling force to the gas shower head 124.

[0048] A plurality of first screws 123 are arranged around the air intake mechanism 122. In this 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, is not easily deformed by high temperature, and avoids the position change of the gas shower head 124 caused by the expansion of the first screws 123. In addition, the use of Hastelloy also ensures the connection stability between the first screws 123 and the gas shower head 124.

[0049] Since part of the first screw 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 screw 123 , a corrosion-resistant layer may be coated on the surface of the first screw 123 .

[0050] In order to ensure the uniformity of plasma distribution in the chamber, it is usually necessary to keep the upper and lower electrodes parallel to each other, that is, the lower surface of the gas shower head and the upper surface of the base are parallel to each other. However, in the process, in order to ensure the film formation rate and film formation quality, it is usually necessary to react at a relatively high process temperature, and the gas shower head is usually made of aluminum or aluminum alloy materials, which will have a large thermal deformation after being heated. As a result, during the high-temperature process, the lower surface of the gas shower head is deformed by heat, resulting in the original parallel state cannot be maintained, affecting the uniformity of plasma distribution. Therefore, the gas shower head 124 described in the present application has an arched upper surface and a lower surface (in Figure 3 In the figure, since the gas shower head 124 is long in the horizontal direction, dot-dash lines are used at both ends to omit drawing. The upper surface of the gas shower head 124 is a downward concave arch, and its central area is lower than the edge area. The lower surface of the gas shower head 124 is an upward concave arch, and its central area is higher than the edge area. The height difference between the central area and the edge area of ​​the upper surface of the gas shower head 124 is H1, and the height difference between the central area and the edge area of ​​the lower surface of the gas shower head 124 is H2, and H1 is greater than H2.

[0051] Next, 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 explained. The gas shower head 124 formed by machining has a height difference between the center area and the edge area of ​​the upper surface of the gas shower head 124 of H1, and a height difference between the center area and the edge area of ​​the lower surface of the gas shower head 124 of H2, and H1 is greater than H2. When assembling the gas shower head 124 into the reaction chamber 200, the gas shower head 124 is connected to the back plate 121 through the suspension device 126 and the first screw 123, and 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, since the reaction chamber 100 is at a process temperature (usually a high temperature of more than 300 degrees), since the suspension device 126 is made of a rigid material and the gas shower head 124 is restricted in the horizontal direction by the suspension device 126, the gas shower head 124 undergoes more thermal deformation in the vertical direction. If at this time the height difference H1 between the center area and the edge area of ​​the upper surface of the gas shower head 124 is smaller than the height difference H2 between the center area and the edge area of ​​the lower surface, the gas shower head 124 will undergo more thermal deformation toward its upper surface, and the parallel relationship between the lower surface of the gas shower head 124 and the upper surface of the base 150 cannot be guaranteed. If the upper surface of the gas shower head 124 If the height difference H1 between the center area and the edge area is equal to the height difference H2 between the center area and the edge area of ​​the lower surface, the machining error caused by machining may cause uncertainty in the thermal deformation direction of the gas shower head 124. Therefore, in the present application, the height difference H1 between the center area and the edge area of ​​the upper surface of the gas shower head 124 is greater than the height difference H2 between the center area and the edge area of ​​the lower surface. Such a setting makes the gas shower head 124 undergo more thermal deformation toward the lower surface with a smaller arch under a high-temperature process environment, so that the lower surface of the gas shower head 124 is roughly parallel to the upper surface of the base 150, thereby ensuring the uniformity of plasma distribution under a high-temperature process environment. At the same time, when installing, the first screw 123 is screwed into the gas shower head 124 for a predetermined number of turns, which can also provide an upward pulling force to the gas shower head 124 under a high-temperature process, ensuring reliable support for the gas shower head 124. Optionally, the height difference H2 between the center area and the edge area of ​​the lower surface of the gas shower head 124 ranges from 0 to 2.5 mm to adapt to different process requirements.

[0052] Furthermore, by evenly disposing 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 remains substantially symmetrical even under high temperature process conditions, thereby achieving more uniform plasma distribution.

[0053] Furthermore, by setting the number of turns that the first screw 123 is screwed into the gas shower head 124, different sizes of pre-tightening forces are provided to the gas shower head 124, thereby adapting to different parameters of the reaction chamber 100. The more turns the first screw 123 is screwed into the gas shower head 124, the greater the pre-tightening force provided to the gas shower head 124 by the first screw 123, and the number of turns that the first screw 123 is screwed into the gas shower head 124 can be adjusted according to actual process requirements.

[0054] Please continue reading Figure 1 and Figure 2 The side wall 130 of the reaction chamber 100 has a protrusion 131 protruding toward the inside of the reaction chamber 100. The protrusion 131 is formed integrally with the side wall 130. The protrusion 131 is arranged on the inner wall of the side wall 130 and protrudes from the side wall 130 in the horizontal direction. The back plate 121 falls on the protrusion 131, the lower surface of the back plate 121 contacts the upper surface of the protrusion 131, and the gas shower head 124 is located on the inner side of the protrusion 131.

[0055] In addition, since the RF power is fed into the reaction chamber through the gas shower head assembly, the gas shower head assembly further includes an insulating device 127, which includes a first insulating baffle 1271 disposed between the back plate 121 and the side wall 130, a second insulating baffle 1272 disposed between the back plate 121 and the upper surface of the protrusion 131, and a third insulating baffle 1273 disposed between the gas shower head 124 and the side wall of the protrusion 131. These insulating baffles are all made of insulating materials. The first insulating baffle 1271 is arranged in the vertical direction to ensure the insulation between the back plate 121 and the side wall 130 on both sides of the first insulating baffle 1271. The second insulating baffle 1271 is arranged between the lower surface of the back plate 121 and the upper surface of the protrusion 131 in the horizontal direction, and the third insulating baffle 1273 is L-shaped, with its vertical surface arranged between the side wall of the protrusion 131 and the side wall of the gas shower head 124, and its horizontal surface arranged on the lower surface of the protrusion 131 and extending into the groove 1241. The first insulating baffle 1271, the second insulating baffle 1272 and the third insulating baffle 1273 ensure insulation between the back plate 121 and the side wall 130, between the back plate 121 and the protrusion 131, and between the gas shower head 124 and the protrusion 131.

[0056] A mounting bracket 111 is also provided above the back plate 121, and the mounting bracket 111 is located above the reaction chamber 100. The mounting bracket 111 and the back plate 121 are connected and fixed via a second connecting device 112, so that the back plate 121 is fixed on the mounting bracket 111. The mounting bracket 111 provides an upward pulling force to the back plate 121 through the second connecting device 112 to bear most of the weight of the back plate 121. The second connecting device 121 can be a plurality of screws 121, and the plurality of screws 121 are also evenly arranged around the air intake mechanism 122 to provide a symmetrical upward pulling force. The screws 121 are also made of Hastelloy, so that it has better hardness, strength and thermal stability.

[0057] In order to ensure a sealed environment in the reaction chamber 100, the gas shower head assembly further includes a sealing structure, which is disposed between the insulating device 127 and the back plate 121, and between the insulating device 127 and the protrusion 131. Specifically, the sealing structure includes a first sealing structure 129 and a second sealing structure 128 disposed along the circumference of the back plate 121, wherein the first sealing structure 129 is located between the second insulating baffle 1272 and the lower surface of the back plate 121, and the second sealing structure 128 is disposed between the second insulating baffle 1272 and the upper surface of the protrusion 131. The first sealing structure 129 and the second sealing structure 128 may be sealing rings, through which the process gas in the reaction chamber 100 is prevented from leaking from the gap between the back plate 121 and the second insulating baffle 1272, and from the gap between the second insulating baffle 1272 and the protrusion 131, thereby ensuring the sealing and vacuum properties of the reaction chamber 100.

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

Claims

1. A gas shower head assembly, arranged in a reaction chamber of a plasma processing device, characterized in that: include: A back plate, the back plate being located at the top of the reaction chamber; A gas shower head, the gas shower head is located below the back plate; A suspension device, wherein a first end of the suspension device is connected to the back plate, and a second end of the suspension device is connected to the gas shower head; A first connecting device, wherein the first connecting device connects the back plate and the upper surface of the gas shower head; the gas shower head has an arched upper surface and a lower surface, the central area of ​​the upper surface of the gas shower head is lower than the edge area, and the central area of ​​the lower surface of the gas shower head is higher than the edge area; the height difference between the central area and the edge area of ​​the upper surface of the gas shower head is greater than the height difference between the central area and the edge area of ​​the lower surface of the gas shower head.

2. The gas showerhead assembly according to claim 1, wherein: The first connecting device is a plurality of screws.

3. The gas showerhead assembly according to claim 2, wherein: By setting the number of turns by which the screw is screwed into the gas shower head, a corresponding pre-tightening force is provided to the gas shower head.

4. The gas showerhead assembly according to claim 3, wherein: The gas shower head assembly further includes an air intake mechanism, the air intake mechanism penetrates the back plate, and a plurality of screws are arranged around the air intake mechanism.

5. The gas showerhead assembly according to claim 3, wherein: The number of the screws is 12.

6. The gas showerhead assembly according to claim 3, wherein: The screw is made of Hastelloy.

7. The gas showerhead assembly according to claim 4, wherein: The surface of the screw is coated with a corrosion-resistant layer.

8. The gas showerhead assembly according to 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.

9. The gas showerhead assembly of claim 1, wherein: The side wall of the reaction chamber has a protrusion protruding toward the inside of the reaction chamber, the lower surface of the back plate contacts the upper surface of the protrusion, and the gas shower head is located inside the protrusion.

10. The gas showerhead assembly of claim 9, wherein: The gas showerhead assembly further includes an insulating device disposed between the back plate and the upper surface of the protrusion, and between the gas showerhead and the side wall of the protrusion.

11. The gas showerhead assembly of claim 10, wherein: The gas showerhead assembly further includes a sealing structure disposed between the insulating device and the back plate, and between the insulating device and an upper surface of the protrusion.

12. The gas showerhead assembly of claim 1, wherein: A mounting bracket is arranged above the back plate, and the mounting bracket is connected and fixed to the back plate via a second connecting device.

13. The gas showerhead assembly of claim 12, wherein: The second connecting device is made of Hastelloy.

14. A plasma processing device, characterized in that: include: Reaction chamber; The gas showerhead assembly according to any one of claims 1 to 13, arranged at the top of the reaction chamber, wherein the gas showerhead assembly delivers process gas into the reaction chamber; A base is arranged in the reaction chamber and is arranged opposite to the gas shower head assembly, and the base is used to carry a substrate to be processed; The mounting bracket is arranged above the reaction chamber, the mounting bracket is connected to the back plate in the gas shower head assembly, and the mounting bracket provides an upward pulling force to the back plate through a second connecting device.

Images