A plasma treatment device and a method for manufacturing a gas spray ring thereof

Abstract

The present invention discloses a plasma processing device and a method for manufacturing a gas spray ring thereof, wherein the device comprises: a vacuum reaction chamber; an upper electrode assembly, located at the top of the vacuum reaction chamber; a lower electrode assembly, located at the bottom of the vacuum reaction chamber, wherein the lower electrode assembly and the upper electrode assembly are arranged opposite to each other, wherein the lower electrode assembly comprises a bearing surface for bearing a wafer; and a gas spray ring, which is arranged around the outer side of the lower electrode assembly, wherein the gas spray ring comprises a plurality of gas supply holes, wherein the gas supply holes are connected to a reaction gas delivery device for delivering the reaction gas to the inside of the vacuum reaction chamber to generate plasma between the upper electrode assembly and the lower electrode assembly. The advantages of the device are that the device realizes the delivery of the reaction gas through the gas spray ring, and the uneven delivery of the reaction gas will not be caused by the installation error of the upper electrode assembly, thereby affecting the etching effect, and the stability of the use of the plasma processing device is greatly improved.

Description

Technical Field

[0001] The invention relates to the field of semiconductor equipment, and in particular to a plasma processing device and a manufacturing method of a gas spray ring thereof. Background Art

[0002] In the manufacturing process of semiconductor devices, plasma etching is a key process for processing wafers into designed patterns. During the entire wafer processing process, the cleanliness of the upper electrode assembly and vacuum reaction chamber of the plasma processing device, as well as the uniformity of the reaction gas and plasma environment, have a huge impact on the etching effect of the wafer.

[0003] In existing plasma processing devices, due to the requirements of the equipment structure, the reaction gas delivery channel is usually composed of gaps between the parts inside the upper electrode assembly. This structure is widely used in the field of wafer etching, especially wafer edge etching. Usually, the reaction gas delivery channel of the device is inside the upper electrode assembly, above the wafer, and its gas outlet is a gap between two parts of the upper electrode assembly. However, in the actual installation process, there are often some installation errors between the parts, and the uniformity of the gap on the entire circumference, that is, the uniformity of the width of the reaction gas delivery channel, cannot be guaranteed to be consistent, resulting in uneven etching. Summary of the invention

[0004] The object of the present invention is to provide a plasma processing device and a method for manufacturing a gas spray ring thereof. The plasma processing device transports the reaction gas to the inside of a vacuum reaction chamber through a gas spray ring, uses a part as a gas supply component, and ensures the output uniformity of the reaction gas in the circumference of the wafer through machining. The uneven delivery of the reaction gas due to the installation error of the upper electrode assembly will not affect the etching effect, thereby greatly improving the use stability of the plasma processing device.

[0005] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0006] A plasma processing device, comprising:

[0007] Vacuum reaction chamber;

[0008] An upper electrode assembly, located at the top of the vacuum reaction chamber;

[0009] A lower electrode assembly is located at the bottom of the vacuum reaction chamber, the lower electrode assembly and the upper electrode assembly are arranged opposite to each other, and the lower electrode assembly comprises a bearing surface for bearing a wafer;

[0010] A gas spray ring is arranged around the outer side of the lower electrode assembly, and the gas spray ring includes a plurality of gas supply holes, and the gas supply holes are connected to a reaction gas delivery device for delivering the reaction gas into the vacuum reaction chamber to generate plasma between the upper electrode assembly and the lower electrode assembly.

[0011] Optionally, the reaction gas delivery device is arranged at the bottom of the vacuum reaction chamber.

[0012] Optionally, the outlet of the gas supply hole is inclined toward the wafer.

[0013] Optionally, the gas supply holes are evenly or unevenly distributed along the circumference of the wafer.

[0014] Optionally, the gas spray ring is made of insulating material.

[0015] Optionally, the insulating material includes ceramic or quartz material.

[0016] Optionally, the inner wall and / or outlet of the gas supply hole is provided with a plasma corrosion resistant coating.

[0017] Optionally, the plasma corrosion-resistant coating material is a Teflon coating, an yttrium oxide film, or an anodized aluminum layer.

[0018] Optionally, the outlet of the gas supply hole is a rounded structure.

[0019] Optionally, the rounded corner diameter is ≥ 2 times the diameter of the gas supply hole.

[0020] Optionally, the plasma is used to etch the edge of the wafer.

[0021] Optionally, a gas injection hole is provided at the center of the upper electrode assembly for providing a non-reactive gas, wherein the non-reactive gas forms a protective gas curtain for the central area of ​​the wafer or cleans the central area of ​​the wafer.

[0022] Optionally, a method for manufacturing a gas spray ring in the plasma processing device comprises:

[0023] Processing a plurality of gas supply holes on the gas spray ring substrate;

[0024] Plating a plasma corrosion resistant coating on the gas supply hole from bottom to top by physical vapor deposition;

[0025] A plasma corrosion resistant coating is plated on the gas supply hole from top to bottom by chemical vapor deposition.

[0026] Optionally, the outlet of the gas supply hole is inclined toward the wafer.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] In a plasma processing device and a method for manufacturing a gas spray ring thereof provided by the present invention, the plasma processing device uses a gas spray ring component to transport the reaction gas into a vacuum reaction chamber, and uses a separate component to realize the transportation of the reaction gas, thereby ensuring the output uniformity of the reaction gas around the wafer, and preventing the installation error of the upper electrode assembly, etc. from causing uneven transportation of the reaction gas and thus affecting the etching effect, thereby greatly improving the use stability of the plasma processing device;

[0029] Furthermore, the outlet of the gas supply hole of the gas spray ring is inclined toward the wafer, and the direction of the reaction gas flow is oblique from bottom to top, which reduces the possibility of particle contaminants falling onto the wafer surface during the process, improves the problem of particle contamination, and further ensures the environment in the vacuum reaction chamber;

[0030] Furthermore, the inner wall and the outlet of the gas supply hole are provided with a plasma corrosion-resistant coating, which increases the service life of the gas spray ring. After the plasma treatment device is put into use, the gas spray ring does not need to be frequently replaced, thus avoiding occupying the working time of the plasma treatment device.

[0031] Furthermore, the outlet of the gas supply hole is a chamfered structure, which reduces the impact of the reaction gas on the side wall of the gas supply hole outlet when it flows out from the gas supply hole outlet, improves the fluidity of the reaction gas, avoids the generation of excess particulate contaminants, and ensures the cleanliness of the etching environment to achieve the best etching effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for the description. Obviously, the drawings described below are an embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work:

[0033] Figure 1 A plasma processing device of the present invention;

[0034] Figure 2 It is a schematic diagram of the gas spray ring of the present invention;

[0035] Figure 3 for Figure 2 AA section diagram of the middle gas spray ring;

[0036] Figure 4 for Figure 3 Enlarged schematic diagram of area B in the middle gas spray ring. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that, in this article, the terms "include", "comprises", "has" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "includes..." or "comprising..." do not exclude the existence of other elements in the process, method, article or terminal device including the elements.

[0039] It should be noted that the drawings are all in very simplified form and use inaccurate ratios, and are only used to conveniently and clearly assist in explaining an embodiment of the present invention.

[0040] like Figure 1As shown, a plasma processing device of the present invention comprises: a vacuum reaction chamber 100, which is surrounded by a reaction chamber body 101 and a chamber end cover 102, and a wafer transfer port 103 is provided on the reaction chamber body 101, and the wafer transfer port 103 is used to transfer the wafer between the inside and outside of the vacuum reaction chamber 100. The vacuum reaction chamber 100 comprises a lower electrode assembly 110, which is arranged at the bottom of the vacuum reaction chamber 100, and the lower electrode assembly 110 is provided with a carrying surface, and the wafer W to be processed introduced into the vacuum reaction chamber 100 is placed on the carrying surface. The vacuum reaction chamber 100 also includes an upper electrode assembly 120 arranged opposite to the lower electrode assembly 110. The upper electrode assembly 120 is located at the top of the vacuum reaction chamber 100. At least one radio frequency power source (not shown in the figure) is applied to at least one of the lower electrode assembly 110 and the upper electrode assembly 120 through a matching network to dissociate the reaction gas into plasma, so that plasma is generated between the edge area of ​​the upper electrode assembly 120 and the lower electrode assembly 110. The plasma is used to etch the edge of the wafer W. Specifically, the plasma contains a large number of active particles such as electrons, ions, excited atoms, molecules and free radicals. The above-mentioned active particles can undergo a variety of physical and / or chemical reactions with the surface of the wafer W to be processed, so that the morphology of the edge of the wafer W to be processed changes, thereby completing the processing of the edge of the wafer W to be processed. A vacuum pump is set at the bottom of the vacuum reaction chamber 100 to discharge the gas waste generated by the reaction.

[0041] In this embodiment, the plasma processing device is suitable for the edge etching of wafer W. In the process of plasma etching the wafer W to produce the designed pattern, some redundant film layers, such as polysilicon layer, nitride layer, metal layer, etc., will accumulate in the outer edge area of ​​wafer W and the outer edge area of ​​the back side, and these redundant film layers may cause pollution to subsequent processes and equipment, so they need to be removed by bevel etching process. In the edge etching process, the reaction gas usually includes etching gas containing F, Cl, etc. and cleaning gas such as O2 and other auxiliary etching gases to perform edge etching process.

[0042] like Figure 1As shown, the upper electrode assembly 120 includes an insulating isolation portion 121 and an upper electrode ring 122. The insulating isolation portion 121 is arranged at the bottom of the movable upper electrode assembly 120, and is arranged opposite to the central area of ​​the wafer W. The insulating isolation portion 121 can be a layer structure or a body structure. The upper electrode ring 122 is arranged around the outside of the insulating isolation portion 121, and the upper electrode ring 122 is arranged opposite to the edge area of ​​the wafer W. The lower electrode assembly 110 includes a lower electrode ring 111. The lower electrode ring 111 is arranged around the bottom of the edge area of ​​the wafer W (the lower electrode ring 111 can also be flush with the lower surface of the wafer W), and the lower electrode ring 111 and the upper electrode ring 122 are arranged opposite to each other. During the process, plasma is generated between the upper electrode ring 122 and the lower electrode ring 111 to perform edge etching of the wafer W.

[0043] like Figure 1 , Figure 2 and Figure 3 As shown in combination, a plasma processing device for processing the edge of a wafer W in this embodiment includes a gas spray ring 140. The gas spray ring 140 is arranged around the outer side of the lower electrode assembly 110, and the gas spray ring 140 includes a plurality of gas supply holes 141. The gas supply holes 141 are connected to a reaction gas delivery device 150, which is used to deliver the reaction gas to the inside of the vacuum reaction chamber 100 to generate plasma between the upper electrode assembly 120 and the lower electrode assembly 110. In the present invention, the gas spray ring 140 is used as a gas supply component to deliver the reaction gas. The single gas spray ring 140 can ensure the uniformity of its pipeline through machining, alleviate the problem of uneven gas outlet of the reaction gas delivered in the circumferential direction, and then ensure the uniformity of gas delivery to ensure the effect of wafer W edge etching.

[0044] In this embodiment, the gas spray ring 140 is made of insulating materials. The gas spray ring 140 made of insulating materials will not interfere with the plasma environment during the process, and will not ignite under the influence of plasma or radio frequency. Optionally, the insulating material includes ceramic or quartz material. In this embodiment, the gas spray ring 140 is made of ceramic material, and its raw materials are made by sintering, which is low-priced and easy to obtain.

[0045] The inner wall and outlet of the gas supply hole 141 are provided with a plasma corrosion resistant coating. Optionally, the plasma corrosion resistant coating material is a Teflon coating or an yttrium oxide film or an anodized aluminum layer. During the plasma etching process, the plasma corrosion resistant coating can reduce the impact of physical bombardment or chemical reaction on the gas spray ring 140, and reduce the possibility of damage to its surface structure. In addition, the plasma corrosion resistant coating also prevents the plasma and the transported reaction gas from damaging the surface structure of the inner wall and outlet of the gas supply hole 141 of the gas spray ring 140, and prevents the body components from being separated from the surface to form solid particles that contaminate the wafer W and affect the etching effect of the edge of the wafer W. Therefore, the plasma corrosion resistant coating material of the gas spray ring 140 further increases the service life of the gas spray ring 140, reduces the loss cost of the plasma processing device, and does not need to frequently replace the gas spray ring 140 after the plasma processing device is put into use, thereby avoiding occupying the working machine time of the plasma processing device.

[0046] In this embodiment, the reaction gas delivery device 150 is arranged at the bottom of the vacuum reaction chamber 100, and the gas spray ring 140 is arranged around the outer side of the lower electrode assembly 110, and the reaction gas delivery does not need to rely on the upper electrode assembly 120. Whether the assembly of the parts in the upper electrode assembly 120 is free of installation errors does not affect the uniformity of the reaction gas delivery, thereby improving the stability of the plasma processing device. In addition, the gas spray ring 140 and the reaction gas delivery device 150 are located at the bottom of the vacuum reaction chamber 100 to prevent particle contaminants from being injected into the vacuum reaction chamber 100 from top to bottom, thereby reducing the possibility of particle contamination and helping to ensure the environment for etching the wafer W.

[0047] Further, such as Figure 4As shown, the outlet of the gas supply hole 141 of the gas spray ring 140 is inclined toward the wafer W, and the direction of the reaction gas flow is oblique from bottom to top. In this embodiment, the outlet of the gas supply hole 141 is located below the wafer, and is specifically located between the wafer W and the vacuum pump. Even if the surface structure of the gas spray ring 140 is damaged in a plasma environment for a long time, resulting in the precipitation of tiny particles on the surface, since the direction of the reaction gas flow is from bottom to top, even if there are tiny particles, it is difficult to transport them from the oblique gas supply hole 141 from bottom to top. Therefore, the oblique structure reduces the possibility of tiny particles falling to the surface of the wafer W during the process, improves the problem of particle contamination, further ensures the environment in the vacuum reaction chamber 100, and improves the edge etching effect of the wafer W. In addition, since the outlet of the gas supply hole 141 is located between the wafer W and the vacuum pump, if a small number of particles are output from the gas supply hole 141, the vacuum pump can also easily discharge the particles out of the vacuum reaction chamber 100. Of course, the outlet position of the gas supply hole 140 is not limited thereto. In another embodiment, the outlet of the gas supply hole 141 is close to the edge of the wafer.

[0048] Optionally, the gas supply holes 141 are evenly or unevenly distributed along the circumference of the wafer W. In this embodiment, the gas supply holes 141 are evenly distributed along the circumference of the wafer W, and the reaction gas is evenly injected into the vacuum reaction chamber 100 from the gas supply holes 141 of the gas spray ring 140 and then evenly distributed in the edge area of ​​the wafer W, so that plasma is formed between the upper electrode assembly 120 and the lower electrode assembly 110 through capacitive coupling. The gas supply holes 141 are evenly distributed along the circumference so that the reaction gas around the edge of the wafer W is evenly distributed, which is conducive to ensuring the etching effect of the edge of the wafer W.

[0049] Furthermore, the outlet of the gas supply hole 141 is a rounded structure 142 (see Figure 4 ). During the process, the reaction gas enters the vacuum reaction chamber 100 from the reaction gas delivery device 150 through the gas supply hole 141 and the outlet of the gas supply hole 141. The chamfered structure 142 reduces the impact of the reaction gas on the side wall at the outlet of the gas supply hole 141 when it flows out from the outlet of the gas supply hole 141, improves the fluidity of the reaction gas, avoids the generation of excess particulate pollutants, and ensures the cleanliness of the etching environment to achieve the best etching effect. Furthermore, the outlet of the gas supply hole 141 is closer to the wafer W, and the chamfered structure 142 reduces the contact range or frequency between the side wall of the outlet and the reaction gas, and also reduces the possibility of corrosion of the outlet side wall by the reaction gas, thereby increasing the service life of the gas spray ring 140, and there is no need to replace the gas spray ring 140 multiple times to affect the experimental work process. Specifically, in this embodiment, the diameter of the chamfer is ≥ 2 times the diameter of the gas supply hole 141.

[0050] In addition, in the present embodiment, a gas injection hole 123 is provided at the center of the upper electrode assembly 120. In the edge etching process, the gas injection hole 123 is used to provide a non-reactive gas during the process, and the non-reactive gas generally includes a buffer gas or a cleaning gas. The buffer gas is used to maintain a high pressure above the wafer W during the edge processing of the wafer W, and to form a protective gas curtain for the central area of ​​the wafer W to protect the central area of ​​the wafer W from being etched by the plasma environment. During the process, the flow rate or pressure of the non-reactive gas can be adjusted to protect the central area of ​​the wafer W from the influence of the plasma environment. The cleaning gas is used to clean the vacuum reaction chamber 100 when there is no wafer W in the vacuum reaction chamber 100.

[0051] In addition, the present invention also provides a method for manufacturing the gas spray ring 140 in the plasma processing device, the method comprising: processing a plurality of gas supply holes 141 on the gas spray ring 140 substrate; coating the gas supply holes 141 with a plasma corrosion-resistant coating by physical vapor deposition (PVD) from bottom to top; and coating the gas supply holes 141 with a plasma corrosion-resistant coating by chemical vapor deposition (CVD) from top to bottom.

[0052] In this embodiment, the substrate of the gas spray ring 140 is a ceramic substrate, and its raw materials are made by sintering, and the manufacturing method is simple and the cost is relatively low. The plasma corrosion resistant coating is a Y2O3 coating to enhance the corrosion resistance of the gas spray ring 140. In addition, in the present application, the outlet of the gas supply hole 141 is inclined toward the wafer W to achieve the supply of the reaction gas.

[0053] To sum up, in a plasma processing device and a method for manufacturing a gas spray ring 140 thereof of the present invention, the plasma processing device combines structures such as an upper electrode assembly 120, a lower electrode assembly 110, a gas spray ring 140 and a reaction gas delivery device 150 to realize the delivery of the reaction gas. The device uses a separate gas spray ring 140 structure that can be machined as a gas supply component, and ensures the output uniformity of the reaction gas in the circumferential direction of the wafer W through machining. The installation error of the upper electrode assembly 120 will not cause uneven delivery of the reaction gas, thereby affecting the etching effect, thereby greatly improving the use stability of the plasma processing device.

[0054] Furthermore, the outlet of the gas supply hole 141 of the gas spray ring 140 is inclined toward the wafer W, and the direction of the reaction gas flow is oblique from bottom to top, which reduces the possibility of particulate contaminants falling onto the surface of the wafer W during the process, improves the problem of particle contamination, and further ensures the environment inside the vacuum reaction chamber 100.

[0055] Furthermore, the inner wall and outlet of the gas supply hole 141 are provided with a plasma corrosion-resistant coating, which increases the service life of the gas spray ring 140. After the plasma processing device is put into use, the gas spray ring 140 does not need to be replaced frequently, avoiding occupying the working time of the plasma processing device.

[0056] Furthermore, the outlet of the gas supply hole 141 is a chamfered structure 142, which reduces the impact of the reaction gas on the side wall of the gas supply hole 141 when it flows out from the outlet of the gas supply hole 141, improves the fluidity of the reaction gas, avoids the generation of excess particulate contaminants, and ensures the cleanliness of the etching environment to achieve the best etching effect.

[0057] It should be noted that the gas spray ring 140 in the present invention is applicable to both capacitively coupled plasma processing devices and inductively coupled plasma processing devices, that is, the plasma processing device of the present invention can be both a capacitively coupled plasma processing device and an inductively coupled plasma processing device.

[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 plasma processing device, It is characterized in that Include: Vacuum reaction chamber; An upper electrode assembly, located at the top of the vacuum reaction chamber; A lower electrode assembly is located at the bottom of the vacuum reaction chamber, the lower electrode assembly and the upper electrode assembly are arranged opposite to each other, and the lower electrode assembly comprises a bearing surface for bearing a wafer; The upper electrode assembly includes an upper electrode ring disposed opposite to the edge region of the wafer, and the lower electrode assembly includes a lower electrode ring disposed opposite to the upper electrode ring, wherein the lower electrode ring is disposed around and below the edge region of the wafer; A gas spray ring is arranged around the outer side of the lower electrode assembly, and the gas spray ring includes a plurality of gas supply holes, and the gas supply holes are connected to a reaction gas delivery device for delivering the reaction gas into the vacuum reaction chamber to generate plasma between the upper electrode ring and the lower electrode ring to etch the edge of the wafer.

2. The plasma processing apparatus according to claim 1, It is characterized in that The reaction gas delivery device is arranged at the bottom of the vacuum reaction chamber.

3. The plasma processing apparatus according to claim 1, It is characterized in that The outlet of the gas supply hole is inclined toward the wafer.

4. The plasma processing apparatus according to claim 1, It is characterized in that The gas supply holes are evenly or unevenly distributed along the circumference of the wafer.

5. The plasma processing apparatus according to claim 1, It is characterized in that The gas spray ring is made of insulating materials.

6. The plasma processing apparatus according to claim 5, It is characterized in that The insulating material includes ceramic or quartz material.

7. The plasma processing apparatus according to claim 1, It is characterized in that The inner wall and / or the outlet of the gas supply hole is provided with a plasma corrosion resistant coating.

8. The plasma processing apparatus according to claim 7, It is characterized in that The plasma corrosion resistant coating material is a Teflon coating, an yttrium oxide film or an anodized aluminum layer.

9. The plasma processing apparatus according to claim 1, It is characterized in that The outlet of the gas supply hole is a rounded structure.

10. The plasma processing apparatus according to claim 9, It is characterized in that The rounded corner diameter is ≥2 times the diameter of the gas supply hole.

11. The plasma processing apparatus according to claim 1, It is characterized in that A gas injection hole is arranged at the center of the upper electrode assembly for providing non-reactive gas. The non-reactive gas forms a protective gas curtain for the central area of ​​the wafer or cleans the central area of ​​the wafer.

12. A method for manufacturing a gas spray ring in a plasma processing device according to any one of claims 1 to 11, It is characterized in that Include: Processing a plurality of gas supply holes on the gas spray ring substrate; Plating a plasma corrosion resistant coating on the gas supply hole from bottom to top by physical vapor deposition; A plasma corrosion resistant coating is plated on the gas supply hole from top to bottom by chemical vapor deposition.

13. The method for manufacturing a gas spray ring according to claim 12, It is characterized in that The outlet of the gas supply hole is inclined toward the wafer.

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