Etching component and etching method

Abstract

The present invention relates to the technical field related to semiconductor processing, and in particular to an etching component and an etching method. The etching component of the present invention includes an electrostatic chuck having a placement table, the placement table having a wafer placement position for placing a wafer; a focusing ring, which is arranged on the electrostatic chuck and arranged around the placement table, and a gas channel is provided in the focusing ring, the gas channel having an air inlet and an air outlet, the air inlet being used to pass gas, and the air outlet facing the wafer placement position; a gas supply component, which is connected to the air inlet and is used to supply inert gas and / or reactive gas to the air inlet to regulate the etching rate of the wafer edge. The present application can directly affect the etching environment of the edge area by providing a gas channel in the focusing ring and using the gas supply component to accurately supply inert gas and / or reactive gas to the wafer edge area, thereby realizing dynamic regulation of the wafer edge etching rate.

Description

Technical Field

[0001] The present invention relates to the technical field related to semiconductor processing, and in particular to an etching component and an etching method. Background Art

[0002] A focus ring is a product used in the etching process of wafer manufacturing. It is designed to improve etch uniformity at the edge or perimeter of the wafer, secure the wafer in place to maintain plasma density, and prevent contamination of the wafer sides. When used with an electrostatic chuck, the wafer rests against the focus ring, held in place by an electrostatic charge. Focus rings are considered consumables primarily because they are subjected to extreme environments such as high temperature, high pressure, and strong chemical corrosion during the semiconductor manufacturing process, particularly during etching. These factors cause changes in the physical and chemical properties of the focus ring, which in turn affects its performance and directly impacts the uniformity of wafer edge etching.

[0003] As the focus ring ages, its thickness decreases, and its ability to shield or protect the wafer edge may weaken. This can result in greater exposure of the wafer edge to the etching environment, increasing the edge etch rate.

[0004] The temperature of the wafer edge area in the cavity is affected by the sealing surface of the electrostatic chuck, and there is a temperature control blind spot. Therefore, the edge effect of wafer etching is often more obvious and lacks effective adjustment means.

[0005] As a consumable part, the focus ring needs to be replaced frequently, in most cases after dozens of power output hours. When it is replaced, the silicon focus ring still has a certain thickness. It is just that the edge effect after thinning makes the etching uniformity poor, so the silicon focus ring needs to be replaced. Summary of the Invention

[0006] The object of the present invention is to provide an etching component and an etching method, so as to improve the uniformity of wafer etching while increasing the service life of the focus ring.

[0007] In order to solve the above technical problems, the present invention provides an etching component.

[0008] The etching assembly of the present invention comprises:

[0009] The electrostatic chuck has a placement platform, wherein the placement platform has a wafer placement position for placing a wafer;

[0010] a focusing ring, disposed on the electrostatic chuck and arranged around the placement table, wherein a gas channel is provided in the focusing ring, the gas channel having an air inlet and an air outlet, the air inlet being used to allow gas to enter, and the air outlet facing the wafer placement position;

[0011] A gas supply assembly is connected to the gas inlet and is used to supply inert gas and / or reactive gas to the gas inlet to regulate the etching rate of the wafer edge.

[0012] Furthermore, the gas channel includes a plurality of branch channels, there are a plurality of gas outlets, and the gas outlets are evenly spaced along the circumference of the wafer placement position, and the branch channels correspond to the gas outlets one by one.

[0013] Furthermore, the focusing ring is provided with an overflow ring groove arranged around the wafer placement position, the opening of the overflow ring groove faces the wafer placement position, and the multiple air outlets are evenly spaced along the circumference at the bottom of the overflow ring groove.

[0014] Furthermore, one air inlet is provided, a plurality of branch channels share one air inlet, and the distances between the plurality of air outlets and the air inlet are equal.

[0015] Furthermore, there are multiple air inlets, and the multiple branch channels are divided into multiple groups. Each group of branch channels includes at least one branch channel and shares one air outlet.

[0016] Furthermore, there are multiple groups of gas supply components, and each group of gas supply components corresponds to one gas inlet.

[0017] Furthermore, the gas channels have multiple layers, each layer of the gas channels is used to pass different types of gases, and the multiple layers of the gas channels are connected.

[0018] Furthermore, a flaring structure is provided at the air outlet.

[0019] Furthermore, the gas supply assembly includes an inert gas branch, a reaction gas branch and a heating element, the inert gas branch is used to introduce inert gas into the air inlet, the reaction gas branch is used to introduce reaction gas into the air inlet, and the heating element is used to heat the inert gas and / or reaction gas; the inert gas branch and the reaction gas branch are both provided with a pressure regulating valve, a flow meter and an air inlet valve.

[0020] Furthermore, the focusing ring includes a first ring piece and a second ring piece, a first channel groove is provided on the lower bottom surface of the first ring piece, and a second channel groove is provided on the upper surface of the second ring piece, and the first ring piece and the second ring piece are fitted together so that the first channel groove and the second channel groove form the gas channel.

[0021] The present invention also provides an etching method, comprising:

[0022] Fix the wafer on the placement table of the electrostatic chuck;

[0023] Inert gas is introduced to the back of the wafer through the gas path in the electrostatic chuck;

[0024] The etching rate of the wafer edge is regulated by introducing inert gas and / or reactive gas to the wafer edge through the gas channel on the focusing ring.

[0025] Furthermore, when the etching rate at the edge of the wafer is higher than the standard etching rate, at least one of the three measures of increasing the flow rate of the inert gas, reducing the flow rate of the reaction gas, and reducing the temperature of the inert gas and the reaction gas is adopted; when the etching rate at the edge of the wafer is lower than the standard etching rate, at least one of the three measures of reducing the flow rate of the inert gas, increasing the flow rate of the reaction gas, and increasing the temperature of the inert gas and the reaction gas is adopted.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects:

[0027] The present application sets a gas channel in the focus ring and uses a gas supply assembly to accurately supply inert gas and / or reactive gas to the edge area of ​​the wafer, which can directly affect the etching environment in the edge area, thereby affecting the reaction speed between the wafer and the reactive gas, and thus realizing dynamic regulation of the wafer edge etching rate. This design breaks through the limitations of the traditional focus ring that relies solely on physical properties to control edge etching, and provides a more flexible and accurate etching control method. The present application can accurately control the etching conditions of the edge area without affecting the etching of the center area of ​​the wafer. This local control method not only improves the etching uniformity of the wafer, but also extends the service life of the focus ring, reduces the frequent replacement due to edge effects, and reduces the production cost of the wafer. If the setting method of the present application is not adopted, relying solely on physical properties to control edge etching will result in poor etching uniformity of the wafer, reducing the surface quality, interface quality and electrical performance reliability of the wafer. In addition, it will also require frequent replacement of the focus ring, increasing the production cost of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic structural diagram of an embodiment of an etching assembly (gas supply assembly is not shown) of the present invention;

[0029] Figure 2 for Figure 1 Schematic diagram of the structure of the focus ring of the etching component;

[0030] Figure 3 for Figure 1 A structural diagram of an embodiment in which the focus ring of the etching assembly is provided with an overflow ring groove;

[0031] Figure 4 for Figure 1A schematic diagram of a partial structure of an embodiment in which the focus ring of the etching assembly is provided with multi-layer gas channels;

[0032] Figure 5 for Figure 1 Schematic diagram of the connection between the gas supply assembly and the focusing ring of the etching assembly.

[0033] Reference numerals:

[0034] 1. Electrostatic chuck;

[0035] 2. Focusing ring; 3. Wafer; 4. Gas channel; 5. Gas inlet; 6. Gas outlet;

[0036] 7. First sealing ring; 8. Second sealing ring; 9. First air blowing pipeline; 10. First area; 11. Second air blowing pipeline; 12. Second area; 13. Branch channel; 14. Overflow ring groove. DETAILED DESCRIPTION

[0037] The etching assembly and etching method of the present invention will be described below with reference to schematic diagrams, which illustrate preferred embodiments of the present invention. It should be understood that those skilled in the art may modify the present invention described herein while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as being generally known to those skilled in the art and not as limiting the present invention.

[0038] The serial numbers assigned to components herein, such as "first," "second," etc., are used solely to distinguish the objects being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings). In the description of the present invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," and the like, indicating positions or relationships, are based on those shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They are not intended to indicate or imply that the device or element referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention.

[0039] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0040] The following paragraphs describe the present invention in more detail by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are greatly simplified and not to exact scale, and are provided solely for the purpose of assisting in the description of the embodiments of the present invention.

[0041] The inventors discovered that in a typical semiconductor etching process, a wafer is placed on an electrostatic chuck and surrounded by a focus ring. When the etching process begins, insufficient temperature control at the edge can cause the etch rate there to differ significantly from that at the center of the wafer, affecting etch uniformity. Furthermore, the lack of precise edge etch rate control forces engineers to frequently replace focus rings, even when they may still be useful.

[0042] When addressing the problem of wafer edge etch rate control, the present applicant first considered the limitations of existing technologies. Traditional methods rely primarily on the physical properties of the focus ring to control edge etch, but this approach lacks flexibility and precision. Therefore, the present applicant began exploring new methods that could dynamically adjust the wafer edge environment.

[0043] One initial idea is to influence the etch rate at the edge by adjusting the temperature of the electrostatic chuck. However, this approach is difficult to achieve precise control and may affect the temperature distribution across the wafer. Another consideration is changing the material or structure of the focus ring, but this would increase costs and make it difficult to adapt to different etching processes.

[0044] Further consideration led the applicant to note the crucial role of gases in the etching process. This led to an innovative idea: to precisely control the gas environment at the wafer edge to regulate the etch rate. Specifically, gas channels could be provided within the focusing ring to introduce specific gases to the wafer edge.

[0045] The advantage of this approach lies in its flexibility and precision. By adjusting the gas type, flow rate, and temperature, the etching environment can be dynamically controlled. For example, introducing an inert gas can reduce the etching rate, while adding a reactive gas can increase it. This approach not only addresses edge effects but also allows for real-time adjustments based on varying etching requirements.

[0046] Based on this idea, this application further improves the technical solution. To achieve precise gas control, it is necessary to design a gas supply assembly that can provide different types of gases and accurately control their flow and temperature. At the same time, the design of the focus ring also needs to be adjusted accordingly to accommodate the gas channel and ensure that the gas can effectively act on the edge area of ​​the wafer.

[0047] After repeated deliberation and optimization, this application ultimately resulted in a novel etching assembly design. This design includes an electrostatic chuck, an improved focus ring, and a specialized gas supply assembly. The electrostatic chuck provides a stable wafer placement platform, the improved focus ring is equipped with gas channels, and the gas supply assembly is responsible for providing precisely controlled gas to these channels.

[0048] Therefore, the present application proposes an etching component, such as Figure 1 and Figure 2 As shown, it includes an electrostatic chuck 1, a focusing ring 2 and a gas supply assembly, wherein the electrostatic chuck 1 has a placement table, and the placement table has a wafer placement position for placing the wafer 3; the focusing ring 2 is set on the electrostatic chuck 1 and arranged around the placement table, and a gas channel 4 is set in the focusing ring 2, and the gas channel 4 has an air inlet 5 and an air outlet 6, the air inlet 5 is used to introduce gas, and the air outlet 6 is directed toward the wafer placement position; the gas supply assembly is connected to the air inlet 5, and is used to supply inert gas and / or reaction gas to the air inlet 5 to regulate the etching rate of the edge of the wafer 3.

[0049] The electrostatic chuck 1 is a device for securing the wafer 3, which can be implemented as a planar structure made of ceramic material. The focusing ring 2 is an annular structure surrounding the electrostatic chuck 1, which can be made of silicon and has a shape that matches the outer contour of the electrostatic chuck 1. The gas channel 4 is a passage for gas circulation provided within the focusing ring 2, including an inlet 5 and an outlet 6. The inlet 5 is located on the outside or bottom of the focusing ring 2 and is used to connect to the gas supply assembly. The outlet 6 faces the position of the wafer 3 on the wafer placement position, ensuring that the gas can directly act on the edge area of ​​the wafer 3. This can be achieved by internal grooving or drilling. The gas supply assembly is connected to the inlet 5 of the focusing ring 2. The device for providing inert gas and reactive gas can be implemented by gas storage tanks, pipelines, and control valves. By precisely controlling the type, flow rate, pressure, and temperature of the gas, the etching environment at the edge of the wafer 3 can be dynamically adjusted.

[0050] The present application provides a gas channel 4 in the focus ring 2 and utilizes a gas supply assembly to precisely supply inert gas and / or reactive gas to the edge region of the wafer 3, thereby directly affecting the etching environment in the edge region, thereby affecting the reaction rate between the wafer 3 and the reactive gas, and thereby achieving dynamic regulation of the edge etching rate of the wafer 3. This design breaks through the limitations of the traditional focus ring that relies solely on physical properties to control edge etching, and provides a more flexible and precise etching control method. The present application can precisely control the etching conditions in the edge region without affecting the etching of the central region of the wafer 3. This local control method not only improves the etching uniformity of the wafer 3, but also improves the surface quality, interface quality, and electrical performance reliability of the wafer 3. At the same time, it also extends the service life of the focus ring 2, reduces the frequent replacement caused by edge effects, and reduces the production cost of the wafer 3. If this setting method of the present application is not adopted, relying solely on physical properties to control edge etching will result in poor etching uniformity of the wafer 3, reduce the surface quality, interface quality, and electrical performance reliability of the wafer 3, and also require frequent replacement of the focus ring, increasing the production cost of the wafer 3.

[0051] In actual operation, when it is detected that the edge etching rate of wafer 3 is too fast, at least one of the following measures can be adopted: increasing the flow rate of the inert gas, reducing the flow rate of the reactive gas, or lowering the temperature of the inert gas and reactive gas, thereby reducing the etching rate of the edge area. Conversely, when the edge etching rate is too slow, at least one of the following measures can be adopted: reducing the flow rate of the inert gas, increasing the flow rate of the reactive gas, or increasing the temperature of the inert gas and reactive gas, to increase the etching rate. This method allows for rapid adjustments based on real-time monitoring results, ensuring the uniformity of the etching process.

[0052] In some embodiments, in order to control the temperature of the wafer 3, a first sealing ring 7 and a second sealing ring 8 are provided on the wafer 3 placement table of the electrostatic suction cup 1, and the diameter of the first sealing ring 7 is smaller than the diameter of the second sealing ring 8. The wafer 3 is placed on the first sealing ring 7 and the second sealing ring 8. A first air blowing pipe 9 and a second air blowing pipe 11 are also provided in the electrostatic suction cup 1. The first air blowing pipe 9 is used to purge gas into the first area 10 formed by the first sealing ring 7, and the second air blowing pipe 11 is used to purge gas into the second area 12 formed by the second sealing ring 8. The gas purged by the first air blowing pipe 9 and the second air blowing pipe 11 is used to control the temperature of the wafer 3. According to the process requirements, the purged gas can be an inert gas for heating the wafer 3 or an inert gas for cooling the wafer 3. The inert gas can be argon, helium or nitrogen.

[0053] In some embodiments, in order to make the gas distribution in the gas channel 4 more uniform, the gas channel 4 includes multiple branch channels 13, there are multiple gas outlets 6, and they are evenly spaced along the circumference of the wafer placement position, and the branch channels 13 correspond one-to-one to the gas outlets 6.

[0054] The provision of multiple gas outlets 6 increases the distribution points of gas output, which helps the gas to cover the edge area of ​​the wafer 3 more evenly. The gas outlets 6 are evenly spaced along the circumference of the placement table to ensure the uniform distribution of gas at the edge of the wafer 3, avoiding the situation where the gas supply is insufficient or excessive in certain areas. This evenly distributed design can effectively reduce the etching unevenness in the edge area of ​​the wafer 3, improve the accuracy and consistency of the etching process, and also improve the surface quality, interface quality and electrical performance reliability of the wafer 3. If the gas outlets 6 are not evenly spaced along the circumference, the gas cannot be evenly distributed at the edge of the wafer 3, resulting in insufficient or excessive gas supply in certain areas, making the etching process uniform, and reducing the surface quality, interface quality and electrical performance reliability of the wafer 3.

[0055] In some embodiments, a flared structure is provided at the gas outlet 6. The flared structure can reduce the gas flow rate by gradually increasing the cross-sectional area of ​​the flow channel, so that the gas changes from concentrated injection to diffuse flow, and avoids the concentrated impact of the gas flow on a certain point, thereby achieving a more uniform gas distribution, improving the etching uniformity of the wafer 3, and also improving the surface quality, interface quality and electrical performance reliability of the wafer 3. If the flared structure is not adopted, the gas flow will be concentrated on a certain point, and the gas cannot be evenly distributed, resulting in different etching speeds at different positions, thereby affecting the uniformity of the etching process and reducing the surface quality, interface quality and electrical performance reliability of the wafer 3.

[0056] Preferably, the flared structure is a trumpet-shaped flared structure or a conical flared structure. In other embodiments, the flared structure can also be other gradually expanding structures, such as a semi-elliptical shape.

[0057] In some embodiments, such as Figure 3 As shown, the focusing ring 2 is also provided with an overflow ring groove 14 arranged around the wafer 3 placement position, the opening of the overflow ring groove 14 faces the wafer placement position, and the multiple air outlets 6 are evenly spaced along the circumference at the bottom of the overflow ring groove 14.

[0058] Since the multiple gas outlets 6 are evenly spaced along the circumferential direction at the bottom of the overflow ring groove 14, the gas flowing out of the gas outlet 6 first enters the overflow ring groove 14. After the gas fills the overflow ring groove 14, it can overflow evenly along the circumferential direction, so that the gas covers the edge area of ​​the wafer 3 more evenly, thereby effectively improving the etching uniformity of the edge area of ​​the wafer 3, further improving the accuracy and consistency of the etching process, and improving the surface quality, interface quality and electrical performance reliability of the wafer 3.

[0059] Preferably, the overflow annular groove 14 is provided with a flared structure at the outlet 6 at the bottom of the groove. The flared structure can reduce the gas flow rate by gradually increasing the cross-sectional area of ​​the flow channel, so that the gas changes from concentrated injection to diffuse flow, thereby making the gas more evenly distributed and filling the overflow annular groove 14. In this way, the uniformity of the gas overflow will be better. Therefore, the flared structure at the overflow annular groove 14 and the outlet 6 can cooperate with each other to further improve the etching uniformity of the edge area of ​​the wafer 3, thereby improving the accuracy and consistency of the etching process. If the overflow annular groove 14 is not provided and the outlet 6 is arranged only in a multi-point distribution form, uneven gas distribution may still occur, which cannot further improve the etching uniformity and cannot further improve the surface quality, interface quality and electrical performance reliability of the wafer 3.

[0060] In other embodiments, Figure 4 As shown, the gas channel 4 has multiple layers, each layer of the gas channel 4 is used to pass different types of gases, and the multiple layers of gas channels 4 are connected.

[0061] Specifically, a multi-layer gas path is designed inside the focusing ring, which facilitates the introduction of gases of different temperatures or types into different layers of gas paths. For example, two layers of gas paths are provided, with the inner gas path 4 being used to introduce reactive gases, and the outer gas path 4 being used to introduce inert gases. For another example, three layers of gas paths 4 may be provided, with the inner gas path 4 being used to introduce reactive gases, the middle gas path 4 being used to introduce inert gases, and the outer gas path 4 being used to introduce specially treated gases, such as microwave plasma treated gases, to further precisely control the etching reaction.

[0062] This multi-layer structural design can be achieved by setting up multiple separation layers inside the silicon focusing ring, each separation layer has an independent air inlet 5 and air outlet 6, and the gas channels 4 of each layer are connected through a set channel to achieve orderly flow and mixing of gases, so that the etching reaction can be further accurately controlled, the etching uniformity of the wafer 3 is improved, and the surface quality, interface quality and electrical performance reliability of the wafer 3 are improved. If the multi-layer structural design is not adopted, it will be difficult to accurately control the flow sequence of the gas, and thus it will be impossible to further accurately control the etching reaction and further improve the surface quality, interface quality and electrical performance reliability of the wafer 3. In some embodiments, the air inlet 5 is provided with one, and the multiple branch channels 13 share one air inlet 5, and the distances between the multiple air outlets 6 and the air inlet 5 are equal.

[0063] Since the distances between all the gas outlets 6 and the gas inlet 5 are equal, the resistance encountered by the gas during the flow process is also basically the same. This ensures that the gas can be evenly distributed to each gas outlet 6, thereby forming a uniform gas distribution at the edge of the wafer 3. Uniform gas distribution is crucial for regulating the etching rate at the edge of the wafer 3, and can effectively improve the etching uniformity at the edge of the wafer 3, and further improve the surface quality, interface quality and electrical performance reliability of the wafer 3. If the distances between the gas outlet 6 and the gas inlet 5 are not equal, the gas cannot be evenly distributed to each gas outlet 6, and thus cannot be evenly distributed at the edge of the wafer 3, and the edge of the wafer 3 cannot be further evenly etched, and the surface quality, interface quality and electrical performance reliability of the wafer 3 cannot be further improved.

[0064] like Figure 2 As shown, taking the focus ring 2 with eight air outlets 6 as an example, the air outlet 6 extends into the interior of the focus ring 2 and then splits into two, four, and eight, thereby forming eight branch channels 13 with equal travel distances. In other embodiments, other numbers of branch channels 13, such as 16 or 32, can be provided as required.

[0065] In other embodiments, there are multiple air inlets 5 , and the multiple branch channels 13 are divided into multiple groups. Each group of branch channels 13 includes at least one branch channel 13 and shares one air outlet 6 .

[0066] Specifically, the design of multiple air inlets 5 provides more entry points for gas supply. Each air inlet 5 can be controlled independently, so that the supply amount and type of gas can be adjusted according to the needs of different areas.

[0067] Furthermore, the design of dividing the branch channels 13 into multiple groups, with each group sharing a single gas outlet 6, enables precise control of gas distribution. This layout allows for more precise regulation of the gas supply to different areas along the edge of the wafer 3. For example, the etching rate can be balanced by adjusting the gas flow in the corresponding group of branch channels 13 based on the etching conditions at different locations along the edge of the wafer 3.

[0068] As a preferred embodiment, multiple gas supply assemblies can be provided, with each group corresponding to a gas inlet 5. This configuration further enhances the ability to independently control each gas inlet 5. Each group of gas supply assemblies can independently adjust the gas type, flow rate, and temperature of its corresponding gas inlet 5, thereby achieving more precise etching control. If only one group of gas supply assemblies is used, it will be impossible to independently control each gas inlet 5, nor will it be possible to accurately control the gas type, flow rate, and temperature of the corresponding gas inlet 5.

[0069] For example, in one embodiment, the etching assembly can be provided with four gas inlets 5, located in four quadrants of the focus ring 2. Each gas inlet 5 is connected to three branch channels 13, each of which is located in the same quadrant and has a gas outlet 6. Four sets of gas supply assemblies are connected to the four gas inlets 5, respectively. In actual operation, the etching rate can be balanced by adjusting the parameters of the corresponding gas supply assemblies according to the etching conditions of different areas on the edge of the wafer 3.

[0070] Specifically, if it is found that the etching rate at the edge of a certain quadrant of the wafer 3 is too high, the etching rate can be reduced by increasing the inert gas flow rate of the gas inlet 5 corresponding to the quadrant or reducing the reactive gas flow rate. Of course, the temperature of the inert gas or reactive gas can also be reduced. Conversely, if the etching rate at the edge of a certain quadrant is too low, the etching rate can be increased by increasing the reactive gas flow rate or reducing the inert gas flow rate. Of course, the temperature of the inert gas or reactive gas can also be increased. In this way, a more uniform etching effect can be achieved at the edge of the wafer 3.

[0071] In one embodiment, Figure 5 As shown, the gas supply assembly includes an inert gas branch, a reaction gas branch and a heating element. The inert gas branch is used to introduce inert gas into the air inlet 5, the reaction gas branch is used to introduce reaction gas into the air inlet 5, and the heating element is used to heat the inert gas and / or reaction gas; the inert gas branch and the reaction gas branch are both provided with a pressure regulating valve, a flow meter and an air inlet valve.

[0072] The inert gas branch can use a variety of inert gases, such as argon, helium, or nitrogen. The reactive gas branch can select appropriate reactive gases, such as fluorine, chlorine, or other reactive gases, based on the specific etching process. The heating element can be an electric heating wire, infrared heating lamp, or other heating device.

[0073] The inert gas branch and the reactive gas branch can be controlled independently, affecting the etching rate by adjusting their respective flow rates, ratios, or temperatures. The heating element can heat both gases simultaneously or separately, further affecting the etching rate through temperature regulation.

[0074] Specifically, the pressure regulating valve can dynamically adjust the gas pressure according to the needs of different etching stages to ensure that the gas enters the system at the optimal pressure. The flow meter monitors the gas flow in real time and feeds the data back to the control system so that the system can adjust the gas supply in time. The air inlet valve can accurately control the opening and closing time of the gas to achieve precise timing control of the gas supply, which is beneficial to improving the etching uniformity of wafer 3, as well as improving the surface quality, interface quality and electrical performance reliability of wafer 3. If the inert gas branch, reaction gas branch and heating element and the corresponding pressure regulating valve, flow meter and air inlet valve are not set separately, it will be impossible to accurately control the supply amount, supply speed and stability of the inert gas and reaction gas.

[0075] For example, a precision pressure regulator can be used on the inert gas branch, with a pressure regulation range of 0-100 kPa and an accuracy of ±0.1 kPa. A mass flowmeter can be used as the flowmeter, with a measurement range of 0-1000 sccm and an accuracy of ±1%. A fast-response solenoid valve with a response time of less than 50 ms can be used as the intake valve. These parameters can be adjusted according to actual needs.

[0076] A similar configuration can be used on the reaction gas branch, but materials with higher corrosion resistance may be selected based on the characteristics of the reaction gas. For example, the pressure regulating valve may use an all-metal seal, the flow meter may use a corrosion-resistant mass flow meter, and the intake valve may use a solenoid valve with a corrosion-resistant coating.

[0077] By placing these control elements on each of the two gas branches, the operator can independently adjust the pressure, flow rate, and supply timing of each gas. This design not only improves the controllability and precision of the etching process, but also allows for flexible adjustment of gas supply parameters to suit different etching requirements, helping to improve etching uniformity and product quality.

[0078] As a preferred embodiment, a predetermined gas supply recipe can be set in the control system. For example, for a specific type of wafer 3 and etching process, the optimal flow ratio, pressure value, and supply timing of the inert gas and reactive gas can be pre-set. In actual operation, the operator only needs to select the corresponding recipe, and the system will automatically adjust the various control elements to achieve the optimal gas supply state. This not only simplifies the operating process, but also improves the etching efficiency and etching consistency of the wafer 3.

[0079] Furthermore, the technical solution of this application helps optimize gas usage efficiency. By precisely controlling the gas supply, unnecessary waste of inert and reactive gases can be reduced, thereby lowering wafer production costs. For example, the gas supply volume and timing can be precisely controlled according to actual needs, avoiding waste caused by excessive gas supply.

[0080] In one embodiment, in order to manufacture the gas channel 4, the focusing ring 2 includes a first ring piece and a second ring piece, a first channel groove is provided on the lower bottom surface of the first ring piece, and a second channel groove is provided on the upper surface of the second ring piece, and the first ring piece and the second ring piece are fitted together so that the first channel groove and the second channel groove enclose the gas channel 4.

[0081] Specifically, by dividing the focus ring 2 into two ring segments and providing channel grooves on each surface, the complex structure of the gas channel 4 can be more easily manufactured. This design not only simplifies the manufacturing process but also improves the precision and consistency of the gas channel 4. When the two ring segments are bonded together, the resulting gas channel 4 can more evenly supply gas to the edge of the wafer 3, thereby more effectively controlling the etching rate.

[0082] Furthermore, this split design facilitates maintenance and replacement of the focus ring 2. When cleaning or replacing the gas channel 4 is necessary, the two ring segments can be easily separated to clean the channel groove. If one of the ring segments is damaged, it can be replaced with a new one. After cleaning or replacement, the two ring segments can be reassembled to form the focus ring 2, significantly improving the maintainability and service life of the focus ring 2. Manufacturing the focus ring 2 without a split design would increase the difficulty and cost of manufacturing the focus ring, and would also be inconvenient for subsequent maintenance and replacement.

[0083] As a preferred embodiment, the first and second ring segments can be made of the same or different materials. For example, high-temperature and corrosion-resistant ceramic materials or special alloy materials can be selected. The first and second channel grooves can be manufactured using precision machining techniques, such as CNC milling or laser etching, to ensure channel accuracy and surface finish.

[0084] In practical applications, the first and second ring segments can be secured together using bolts or a snap-fit ​​structure. To ensure airtightness, sealing rings or sealant can be provided on the contact surfaces of the two ring segments. The cross-section of the gas channel 4 can be designed to be circular, elliptical, or other suitable shapes to optimize gas flow characteristics.

[0085] This design simplifies and improves the precision of gas channel 4. Requiring only a shallow groove on each ring segment, this significantly reduces manufacturing complexity and cost compared to machining complex internal channels on the entire focusing ring 2. Furthermore, because the channel is formed from two ring segments, it can be inspected and cleaned more easily, improving maintenance convenience.

[0086] The present application also provides an etching method, comprising:

[0087] S100: Fix the wafer on the placement table of the electrostatic chuck;

[0088] S200: Inert gas is introduced to the back of the wafer through the gas path in the electrostatic chuck;

[0089] S300: Inert gas and / or reactive gas is introduced to the edge of the wafer through the gas channel on the focusing ring to regulate the etching rate of the edge of the wafer.

[0090] Specifically, in step S100 , the fixation can be achieved by electrostatic force or mechanical clamping, etc. During the fixation process, it is necessary to ensure uniform contact between the wafer and the placement table to avoid local stress concentration.

[0091] In step S200, a gas path network can be designed inside the electrostatic chuck to ensure that the inert gas is evenly distributed on the back of the wafer. The inert gas can be helium, argon or nitrogen, etc. The specific choice depends on the requirements of the etching process. The gas flow and pressure can be adjusted by a precise control system to adapt to different etching conditions. This step helps to control the temperature and pressure on the back of the wafer, thereby indirectly affecting the etching process. By adjusting the temperature and pressure of the back gas, the overall temperature distribution of the wafer can be accurately controlled, thereby affecting the uniformity of the etching rate.

[0092] In step S300, the etch rate at the wafer edge can be directly influenced by controlling the type and amount of gas introduced. The gas channel on the focusing ring can be designed as a ring structure, with multiple gas outlets evenly distributed along the wafer edge. A single gas inlet can be provided, ensuring uniform gas flow; alternatively, multiple gas inlets can be provided, each independently controllable, enabling fine-tuning of the etch rate for different regions of the wafer.

[0093] Furthermore, in order to control the etching rate of the wafer edge, when the etching rate of the wafer edge is higher than the standard etching rate, at least one of the three measures of increasing the flow rate of the inert gas, reducing the flow rate of the reaction gas, and reducing the temperature of the inert gas and the reaction gas is adopted; when the etching rate of the wafer edge is lower than the standard etching rate, at least one of the three measures of reducing the flow rate of the inert gas, increasing the flow rate of the reaction gas, and increasing the temperature of the inert gas and the reaction gas is adopted.

[0094] The etching method of the present application can be implemented by the etching component of any embodiment of the above technical solution.

[0095] The etching method of the present application solves the problem of controlling the wafer edge etch rate by introducing a controllable gas flow at the wafer edge. By adjusting the flow rate, ratio, and temperature of the inert gas and the reactive gas, the etching environment in the edge region can be precisely controlled, thereby influencing the reaction rate between the wafer and the reactive gas and, in turn, controlling the etching rate. The advantage of this method is that the etching parameters can be adjusted dynamically in real time, improving the flexibility and accuracy of the etching process. The present application can precisely control the etching conditions in the edge region without affecting the etching of the center region of the wafer. This localized control method not only improves the wafer etching uniformity, but also improves the wafer's surface quality, interface quality, and electrical performance reliability. It also extends the service life of the focus ring, reduces the frequent replacement caused by edge effects, and reduces the production cost of the wafer. If this configuration is not adopted, relying solely on physical properties to control the edge etching will result in poor wafer etching uniformity, reduced wafer surface quality, interface quality, and electrical performance reliability, and the need for frequent focus ring replacement, increasing the production cost of the wafer.

[0096] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. An etching component, characterized in that: include: The electrostatic chuck has a placement platform, wherein the placement platform has a wafer placement position for placing a wafer; a focusing ring, disposed on the electrostatic chuck and arranged around the placement table, wherein a gas channel is provided in the focusing ring, the gas channel having an air inlet and an air outlet, the air inlet being used to allow gas to enter, and the air outlet facing the wafer placement position; a gas supply assembly connected to the gas inlet, configured to supply an inert gas and / or a reactive gas to the gas inlet to regulate the etching rate of the wafer edge, wherein when the etching rate of the wafer edge is higher than the standard etching rate, at least one of the following three measures is adopted: increasing the flow rate of the inert gas, reducing the flow rate of the reactive gas, or reducing the temperature of the inert gas and the reactive gas; and when the etching rate of the wafer edge is lower than the standard etching rate, at least one of the following three measures is adopted: reducing the flow rate of the inert gas, increasing the flow rate of the reactive gas, or increasing the temperature of the inert gas and the reactive gas; The gas channel includes a plurality of branch channels, and the gas outlets are multiple and are evenly spaced along the circumference of the wafer placement position, and the branch channels correspond to the gas outlets one by one; The focusing ring is also provided with an overflow ring groove arranged around the wafer placement position, the opening of the overflow ring groove faces the wafer placement position, and multiple gas outlets are evenly spaced along the circumference at the bottom of the overflow ring groove. The gas outlet at the bottom of the overflow ring groove is provided with a flaring structure, and the strokes between the multiple gas outlets and the gas inlet are equal, so that the gas encounters the same resistance during the flow process and is evenly distributed to each gas outlet, and the flaring structure changes the gas from concentrated injection to diffuse flow, filling the overflow ring groove and then overflowing evenly along the circumference to cover the edge area of ​​the wafer.

2. The etching assembly according to claim 1, characterized in that One air inlet is provided, and a plurality of branch channels share one air inlet.

3. The etching assembly according to claim 1, characterized in that There are multiple air inlets, and the multiple branch channels are divided into multiple groups. Each group of branch channels includes at least one branch channel and shares one air outlet.

4. The etching assembly according to claim 3, characterized in that: There are multiple groups of gas supply components, and each group of gas supply components corresponds to one gas inlet.

5. The etching assembly according to claim 1, characterized in that: The gas channels have multiple layers, each layer of the gas channels is used to introduce different types of gases, and the multiple layers of the gas channels are connected.

6. The etching assembly according to claim 1, characterized in that The gas supply assembly includes an inert gas branch, a reaction gas branch and a heating element. The inert gas branch is used to introduce inert gas into the air inlet, the reaction gas branch is used to introduce reaction gas into the air inlet, and the heating element is used to heat the inert gas and / or reaction gas; the inert gas branch and the reaction gas branch are both provided with a pressure regulating valve, a flow meter and an air inlet valve.

7. The etching assembly according to claim 1, characterized in that: The focusing ring includes a first ring piece and a second ring piece, a first channel groove is provided on the lower bottom surface of the first ring piece, and a second channel groove is provided on the upper surface of the second ring piece, and the first ring piece and the second ring piece are fitted together so that the first channel groove and the second channel groove form the gas channel.

8. An etching method, characterized in that: The method is implemented by the etching assembly according to any one of claims 1 to 7, comprising: Fix the wafer on the placement table of the electrostatic chuck; Inert gas is introduced to the back of the wafer through the gas path in the electrostatic chuck; The etching rate of the wafer edge is regulated by introducing inert gas and / or reactive gas to the edge of the wafer through the gas channel on the focusing ring; when the etching rate of the wafer edge is higher than the standard etching rate, at least one of the three measures of increasing the flow rate of the inert gas, reducing the flow rate of the reactive gas, and reducing the temperature of the inert gas and the reactive gas is adopted; when the etching rate of the wafer edge is lower than the standard etching rate, at least one of the three measures of reducing the flow rate of the inert gas, increasing the flow rate of the reactive gas, and increasing the temperature of the inert gas and the reactive gas is adopted.

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