Gas spray head assembly and plasma treatment device

Abstract

A gas spray head assembly and a plasma treatment device are disclosed. The gas spray head assembly is disposed within the reaction chamber of the plasma treatment device and includes: a back plate; a gas spray head 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 spray head; a first connecting device connecting the back plate and the upper surface of the gas spray head; the gas spray head has an arched upper surface and a lower surface, the central region of the upper surface is lower than the edge region, the central region of the lower surface is higher than the edge region, and the height difference between the central region and the edge region of the upper surface is greater than the height difference between the central region and the edge region of the lower surface; the present invention ensures that the lower surface of the gas spray head is approximately parallel to the upper surface of the base under high-temperature process conditions, thereby guaranteeing the uniformity of plasma distribution below the gas spray head.

Description

Technical Field

[0001] This invention relates to the field of semiconductor processing, and more specifically to a gas spray head assembly and a plasma processing device. Prior Technology

[0002] Plasma-enhanced chemical vapor deposition (PECVD) is a large-area thin-film deposition apparatus, commonly 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) for display manufacturing. PECVD supplies process gases to the substrate via a gas spray head assembly, where the gas spray head is typically made of aluminum or aluminum alloy, and its edges are usually connected to the reaction chamber via a suspension mechanism. During the process, due to the high temperature inside the reaction chamber, the gas spray head inevitably undergoes continuous deformation under the high temperature. As a result, the plasma, which should have been evenly distributed below the gas spray head, becomes unevenly distributed due to the deformation of the gas spray head, affecting the substrate processing effect.

[0003] The statements herein provide only background information in relation to the present invention and do not necessarily constitute prior art. Summary of the Invention

[0004] The purpose of this invention is to provide a gas spray head assembly and a plasma treatment device, which makes the lower surface of the gas spray head approximately parallel to the upper surface of the base under high-temperature process conditions, thereby ensuring the uniformity of plasma distribution in the reaction chamber.

[0005] To achieve the above objectives, the present invention provides a gas spray head assembly disposed within the reaction chamber of a plasma treatment device, comprising: Back plate, the back plate being located at the top of the reaction chamber; A gas spray head, 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 spray head; A first connecting device is disposed between the back plate and the gas spray head, connecting the upper surfaces of the back plate and the gas spray head; The gas spray head has an arched upper surface and a lower surface. The central region of the upper surface of the gas spray head is lower than the edge region, and the central region of the lower surface of the gas spray 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 spray head is greater than the height difference between the central region and the edge region of the lower surface of the gas spray head.

[0006] Optionally, the first connecting device may be a plurality of screws.

[0007] Optionally, a corresponding preload can be provided to the gas spray head by setting the number of turns the screw is screwed into the gas spray head.

[0008] Optionally, the gas spray head assembly further includes an air intake mechanism that extends through the back plate, and a plurality of screws are arranged around the air intake mechanism.

[0009] Optionally, the number of screws is 12.

[0010] Optionally, the screw is made of Hastelloy.

[0011] Optionally, the screw surface is coated with a corrosion-resistant layer.

[0012] 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 spray head.

[0013] Optionally, the sidewall of the reaction chamber has a protrusion that extends into the reaction chamber, the lower surface of the back plate contacts the upper surface of the protrusion, and the gas spray head is located inside the protrusion.

[0014] Optionally, the gas spray head assembly further includes an insulation device disposed between the back plate and the upper surface of the protrusion, and between the gas spray head and the side wall of the protrusion.

[0015] Optionally, the gas spray head assembly further includes a sealing structure disposed between the insulating device and the back plate, and between the insulating device and the upper surface of the protrusion.

[0016] Optionally, a mounting bracket is provided above the back plate, and the mounting bracket is connected and fixed to the back plate by a second connecting device.

[0017] Optionally, the second connecting device is made of Hastelloy.

[0018] The present invention also proposes a plasma treatment apparatus, comprising: reaction chamber; A gas spray head assembly is disposed at the top of the reaction chamber, and the gas spray head assembly supplies process gas into the reaction chamber; A base is disposed within the reaction chamber and positioned opposite the gas spray head assembly; the base is used to support the substrate to be processed. A mounting bracket is positioned above the reaction chamber and is connected to the back plate of the gas spray head assembly. The mounting bracket provides an upward pulling force to the back plate through a second connecting device.

[0019] Compared with the prior art, the technical solution of the present invention has at least the following advantages and beneficial effects:

[0020] The gas spray head assembly provided by this invention includes a back plate and a gas spray head located below the back plate. The gas spray head has an arched upper surface and a lower surface. The central region of the upper surface of the gas spray head is lower than the edge region, and the central region of the lower surface of the gas spray 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 spray head is greater than the height difference between the central region and the edge region of the lower surface of the gas spray head. This ensures that, under high-temperature process conditions, when the gas spray head undergoes thermal deformation in the vertical direction, it tends to face more towards the lower surface. Furthermore, under high-temperature process conditions, the lower surface of the gas spray head is approximately parallel to the upper surface of the base, thereby ensuring the uniformity of plasma distribution below the gas spray head.

[0021] In this invention, the height difference between the central and edge regions of the upper surface of the gas spray head is greater than the height difference between the central and edge regions of the lower surface of the gas spray head. Furthermore, the gas spray head assembly uses multiple screws as a first connecting device. The preload applied to the first connecting device during gas spray head installation can be maintained under high-temperature process conditions, thereby improving the reliability of the first connecting device in supporting the gas spray head.

[0022] The gas spray head assembly of the present invention includes an insulation device to ensure insulation between the back plate, the gas spray head and the side wall of the reaction chamber, and a sealing device to prevent process gas leakage and ensure the airtightness of the reaction chamber. Simple Explanation of the Diagram

[0023] Figure 1 is a schematic diagram of the structure of a plasma treatment device according to the present invention; Figure 2 is a partial schematic diagram of a plasma treatment device according to the present invention; Figure 3 is a schematic diagram of the structure of the gas spray head of the present invention. Implementation

[0024] The technical solutions, structural features, achieved objectives and effects of the present invention will be described in detail below with reference to Figures 1 to 3 in the embodiments of the present invention.

[0025] It should be noted that the drawings are in a very simplified form and use non-precise proportions. They are only used to facilitate and clarify the purpose of illustrating the embodiments of the present invention, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed in the present invention, provided that it does not affect the effects and objectives that the present invention can produce.

[0026] It should be noted that, in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only the expressly listed elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0027] Inside the reaction chamber of the plasma processing apparatus, a gas spray head is positioned at the top of the chamber, opposite the substrate support. The gas spray head is also connected to an external gas supply device to provide process gas to the area above the substrate. During the processing, due to the high temperature within the reaction chamber, the gas spray head inevitably deforms under the high temperature. This deformation is particularly pronounced in the reaction chambers used in flat panel displays, where the gas spray head has a larger area. Furthermore, the deformation of the gas spray head affects the uniformity of plasma distribution below it, thus impacting the substrate processing outcome.

[0028] To address the aforementioned problems, this invention proposes a gas spray head assembly and a plasma treatment device. The gas spray head assembly is disposed within the reaction chamber of the plasma treatment device and includes a back plate and a gas spray head. A suspension device connects the back plate and the gas spray head, and a first connecting device is provided between the gas spray head and the back plate. The height difference between the central region and the edge region of the upper surface of the gas spray head is greater than the height difference between the central region and the edge region of the lower surface of the gas spray head.

[0029] The technical solutions of the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0030] Referring to Figure 1, the plasma treatment apparatus provided by the present invention includes a reaction chamber 100, which is surrounded by side walls 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 for supporting the substrate 140 to be treated. A gas spray head assembly is provided at the top of the reaction chamber 100, and the gas spray head assembly is arranged opposite to the base 150. The gas spray head assembly is connected to an external gas supply device and supplies process gas into the reaction chamber 100.

[0031] Referring to Figure 2, the gas spray head assembly includes a back plate 121 and a gas spray head 124. The back plate 121 is located at the top of the reaction chamber 100, and the gas spray head 124 is disposed below the back plate 121 and connected to the back plate 121 via 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 spray head 124. The back plate 121 bears the main weight of the gas spray head 124 through the suspension device 126. The first end of the suspension device 126 is connected to the back plate 121 and fixed by a second screw 125, and the second end of the suspension device 126 is connected to the edge of the gas spray head 124. In some embodiments, the sidewall of the gas spray head 124 is provided with a groove 1241, and the second screw 125 connects the second end of the suspension device 126 to the groove 1241 of the gas spray head 124, thereby fixing the edge of the gas spray head 124 to the underside of the back plate 121 via the suspension device 126. The suspension device 126 can be multiple arc shapes, spaced apart circumferentially along the outer wall of the gas spray head 124, with the shape of each suspension device 126 matching the outer wall of the gas spray head 124. In other embodiments, the suspension device 126 can also be a complete frame shape, arranged circumferentially along the outer wall of the gas spray head 124, with its shape matching the outer wall of the gas spray head 124.

[0032] The gas spray head assembly also includes an air intake mechanism 122, which is disposed in the central region of the back plate 121 and extends through 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 spray head 124, and the air intake mechanism 122 inputs process gas into the gas diffusion cavity.

[0033] Please refer to Figure 3. The gas spray head 124 has multiple gas channels 1242 from top to bottom, so that the process gas that enters the gas diffusion chamber through the gas inlet mechanism 122 is uniformly introduced into the reaction chamber 100 through these gas channels 1242.

[0034] Referring to Figure 1, a first connecting device is also provided between the back plate 121 and the gas spray head 124. This first connecting device connects the upper surfaces of the back plate 121 and the gas spray head 124, assisting in providing an upward pulling force to the gas spray head 124. Preferably, the first connecting device is located in the central region of the gas spray head 124. In this embodiment, multiple first screws 123 are used as the first connecting device. Each first screw 123 penetrates the back plate 121 from top to bottom and is screwed into the gas spray head 124 from top to bottom, thereby connecting the back plate 121 and the gas spray head 124 and providing an upward pulling force to the gas spray head 124.

[0035] Multiple first screws 123 are arranged around the air intake mechanism 122. In this embodiment, the number of first screws 123 is 12. The first screws 123 are made of Hastelloy, which gives them excellent strength, hardness, and thermal stability. They are not easily deformed by high temperatures, thus avoiding changes in the position of the gas spray head 124 caused by the expansion of the first screws 123. Furthermore, the use of Hastelloy also ensures the connection stability between the first screws 123 and the gas spray head 124.

[0036] Since part of the first screw 123 is located inside the gas diffusion chamber 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 can also be coated on the surface of the first screw 123.

[0037] To ensure uniform plasma distribution within the chamber, it is typically necessary to maintain the parallelism between the upper and lower electrodes, i.e., the lower surface of the gas spray head and the upper surface of the base must be parallel. However, during the process, to ensure film formation rate and quality, the reaction usually needs to be carried out at relatively high process temperatures. The gas spray head is usually made of aluminum or aluminum alloy, which undergoes significant thermal deformation upon heating. This causes the lower surface of the gas spray head to deform under high temperatures, making it impossible to maintain the original parallel state and affecting the uniformity of plasma distribution. Therefore, the gas spray head 124 described in this application has arched upper and lower surfaces (in Figure 3, since the gas spray head 124 is relatively long in the horizontal direction, dashed lines are used at both ends to omit the drawing). The upper surface of the gas spray head 124 is a downward-concave arch, with its central region lower than its edge region; the lower surface of the gas spray head 124 is an upward-concave arch, with its central region higher than its edge region. The height difference between the center region and the edge region of the upper surface of the gas spray head 124 is H1, and the height difference between the center region and the edge region of the lower surface of the gas spray head 124 is H2, and H1 is greater than H2.

[0038] The following explains the arched relationship between the upper and lower surfaces of the gas spray head 124 and the principle behind the support of the gas spray head 124 by the first screw 123. The machined gas spray head 124 has a height difference of H1 between the center and edge regions of its upper surface and H2 between the center and edge regions of its lower surface, with H1 being greater than H2. When assembling the gas spray head 124 into the reaction chamber 200, the gas spray head 124 is connected to the back plate 121 via the suspension device 126 and the first screw 123. The first screw 123 is screwed into the gas spray head 124 a predetermined number of turns to complete the assembly of the reaction chamber 100. However, during the processing, because the reaction chamber 100 is at a process temperature (usually above 300 degrees Celsius), and because the suspension device 126 is made of rigid material, and the gas spray head 124 is restricted horizontally by the suspension device 126, the gas spray head 124 undergoes more thermal deformation in the vertical direction. If the height difference H1 between the center and edge regions of the upper surface of the gas spray head 124 is less than the height difference H2 between the center and edge regions of its lower surface, the gas spray head 124 will undergo more thermal deformation towards its upper surface, making it impossible to guarantee the parallel relationship between the lower surface of the gas spray head 124 and the upper surface of the base 150. If the upper surface of the gas spray head 124... The height difference H1 between the center and edge regions of the upper surface is equal to the height difference H2 between the center and edge regions of the lower surface. Machining errors can cause uncertainty in the direction of thermal deformation of the gas spray head 124. Therefore, in this application, the height difference H1 between the center and edge regions of the upper surface of the gas spray head 124 is greater than the height difference H2 between the center and edge regions of the lower surface. This design allows the gas spray head 124 to undergo more thermal deformation towards the lower surface with a smaller arch under high-temperature processing conditions, making the lower surface of the gas spray head 124 approximately parallel to the upper surface of the base 150, thus ensuring the uniformity of plasma distribution under high-temperature processing conditions. Simultaneously, the first screw 123 being screwed into the gas spray head 124 a predetermined number of times during installation can also provide upward tension to the gas spray head 124 under high-temperature processing conditions, ensuring reliable support for the gas spray head 124. Optionally, the height difference H2 between the center and edge regions of the lower surface of the gas spray head 124 can range from 0 to 2.5 mm to adapt to different process requirements.

[0039] Furthermore, by arranging multiple first screws 123 evenly around the air intake mechanism 122, a uniform and symmetrical upward pulling force is provided to the gas spray head 124, so that the shape of the lower surface of the gas spray head 124 remains basically symmetrical even under high-temperature process conditions, thereby achieving a more uniform plasma distribution.

[0040] Furthermore, by adjusting the number of turns the first screw 123 makes into the gas spray head 124, different preload forces can be provided to the gas spray head 124, thereby adapting to different reaction chamber 100 parameters. The more turns the first screw 123 makes into the gas spray head 124, the greater the preload force provided by the first screw 123 to the gas spray head 124. The number of turns the first screw 123 makes into the gas spray head 124 can be adjusted according to actual process requirements.

[0041] Please refer to Figures 1 and 2. The sidewall 130 of the reaction chamber 100 has a protrusion 131 that protrudes inward into the reaction chamber 100. The protrusion 131 is integrally formed with the sidewall 130 and is disposed on the inner wall of the sidewall 130, protruding horizontally out of the sidewall 130. The back plate 121 rests on the protrusion 131, and the lower surface of the back plate 121 contacts the upper surface of the protrusion 131. The gas spray head 124 is located inside the protrusion 131.

[0042] Furthermore, since the radio frequency power supply is fed into the reaction chamber through the gas spray head assembly, the gas spray head assembly also includes an insulation device 127. The insulation device 127 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 spray head 124 and the side wall of the protrusion 131. All these insulating baffles are made of insulating material. The first insulating baffle 1271 is arranged vertically, ensuring insulation between the back plate 121 and the side wall 130 on both sides of the first insulating baffle 1271. The second insulating baffle 1272 is arranged horizontally between the lower surface of the back plate 121 and the upper surface of the protrusion 131. The third insulating baffle 1273 is L-shaped, with its vertical surface disposed between the side wall of the protrusion 131 and the side wall of the gas spray head 124, and its horizontal surface disposed on the lower surface of the protrusion 131 and extending into the groove 1241. Through the aforementioned first insulating baffle 1271, second insulating baffle 1272, and third insulating baffle 1273, insulation is ensured between the back plate 121 and the side wall 130, between the back plate 121 and the protrusion 131, and between the gas spray head 124 and the protrusion 131.

[0043] A mounting bracket 111 is also provided above the back plate 121. The mounting bracket 111 is located above the reaction chamber 100. The mounting bracket 111 is connected and fixed to the back plate 121 through a second connecting device 112, thereby fixing the back plate 121 to 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 112 can be multiple screws 121. The multiple screws 121 are also evenly arranged around the air intake mechanism 122 to provide symmetrical upward pulling force. The screws 121 are also made of Hastelloy, which gives them better hardness, strength and thermal stability.

[0044] To ensure a sealed environment within the reaction chamber 100, the gas spray head assembly also includes a sealing structure. This sealing structure 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 arranged circumferentially along the back plate 121. 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 can be sealing rings. This sealing structure prevents process gas 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 within the reaction chamber 100, thereby ensuring the sealing and vacuum properties of the reaction chamber 100.

[0045] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above. Therefore, the scope of protection of the present invention should be defined by the appended claims.

[0046] 100: Reaction Chamber 111: Mounting bracket 112: Second connecting device 121: Backplate 122: Intake mechanism 123: First screw 124: Gas spray head 1241: Groove 1242: Gas Channel 125: Second screw 126: Suspension device 127: Insulation device 1271: First insulating baffle 1272: Second insulating baffle 1273: Third Insulating Baffle 128: Second sealing structure 129: First sealing structure 130: Sidewall 131: Protrusion 140: substrate 150: Base 160:Bottom wall 200: Reaction Chamber

Claims

1. A gas spray head assembly, disposed within the reaction chamber of a plasma treatment device, comprising: A back plate, located at the top of the reaction chamber; A gas spray head, the gas spray head being 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 spray head; a first connecting device, which connects the back plate and the upper surface of the gas spray head; the gas spray head has an arched upper surface and a lower surface, the central region of the upper surface of the gas spray head is lower than the edge region, and the central region of the lower surface of the gas spray 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 spray head is greater than the height difference between the central region and the edge region of the lower surface of the gas spray head.

2. The gas spray head assembly as claimed in claim 1, wherein, The first connecting device consists of multiple screws.

3. The gas spray head assembly as claimed in claim 2, wherein, By setting the number of turns the screw is screwed into the gas spray head, a corresponding preload force is provided to the gas spray head.

4. The gas spray head assembly as claimed in claim 3, wherein, The gas spray head assembly also includes an air intake mechanism that extends through the back plate, and a plurality of screws are arranged around the air intake mechanism.

5. The gas spray head assembly as claimed in claim 3, wherein, The number of screws is 12.

6. The gas spray head assembly as claimed in claim 3, wherein, The screw is made of Hastelloy.

7. The gas spray head assembly as claimed in claim 4, wherein, The screw surface is coated with a corrosion-resistant layer.

8. The gas spray head assembly as claimed in 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 spray head.

9. The gas spray head assembly as claimed in claim 1, wherein, The sidewall of the reaction chamber has a protrusion that extends into the reaction chamber. The lower surface of the back plate contacts the upper surface of the protrusion, and the gas spray head is located inside the protrusion.

10. The gas spray head assembly as claimed in claim 9, wherein, The gas spray head assembly also includes an insulation device disposed between the back plate and the upper surface of the protrusion, and between the gas spray head and the side wall of the protrusion.

11. The gas spray head assembly as claimed in claim 10, wherein, The gas spray head assembly also includes a sealing structure disposed between the insulating device and the back plate, and between the insulating device and the upper surface of the protrusion.

12. The gas spray head assembly as claimed in claim 1, wherein, A mounting bracket is provided above the back plate, and the mounting bracket is connected and fixed to the back plate by a second connecting device.

13. The gas spray head assembly as claimed in claim 12, wherein, The second connecting device is made of Hastelloy.

14. A plasma treatment apparatus, comprising: reaction chamber; The gas spray head assembly as described in any one of claims 1 to 13 is disposed at the top of the reaction chamber, and the gas spray head assembly delivers process gas into the reaction chamber; A base is disposed inside the reaction chamber and opposite to the gas spray head assembly. The base is used to support the substrate to be processed. A mounting bracket is disposed above the reaction chamber and is connected to the back plate in the gas spray head assembly. The mounting bracket provides an upward pulling force to the back plate through a second connecting device.

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