Etching assembly and etching method

Abstract

The invention relates to the technical field related to semiconductor processing, in particular to an etching assembly and an etching method. The etching assembly comprises an electrostatic chuck which is provided with a placing table, and the placing table is provided with a wafer placing position used for placing a wafer; the focusing ring is arranged on the electrostatic chuck and arranged around the placement table, a gas channel is arranged in the focusing ring, the gas channel is provided with a gas inlet and a gas outlet, the gas inlet is used for introducing gas, and the gas outlet faces the wafer placement position; and the gas supply assembly is connected with the gas inlet and is used for supplying inert gas and / or reaction gas to the gas inlet to regulate and control the etching rate of the wafer edge. According to the invention, the gas channel is arranged in the focusing ring, and the inert gas and / or the reaction gas are accurately supplied to the edge area of the wafer by using the gas supply assembly, so that the etching environment of the edge area can be directly influenced, and the dynamic regulation and control of the etching rate of the edge of the wafer can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field related to semiconductor processing, and particularly 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, aiming to improve the etching uniformity of the wafer edge or periphery, fix the wafer in place to maintain the plasma density, and prevent the side of the wafer from being contaminated. When used with an electrostatic chuck, the wafer leans against the focus ring and is fixed in place by static charges. The focus ring is regarded as a consumable, mainly because in the semiconductor manufacturing process, especially in the etching process, it experiences extreme environments such as high temperature, high pressure, and strong chemical corrosion. These factors cause changes in the physical and chemical properties of the focus ring, thereby affecting its performance and directly affecting the etching uniformity of the wafer edge.

[0003] As the usage time of the focus ring increases, the thickness of the silicon focus ring decreases, and its shielding or protective effect on the wafer edge may weaken. This may lead to more exposure of the wafer edge area to the etching environment, thereby increasing the edge etching rate.

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

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

[0006] The purpose of the present invention is to provide an etching component and an etching method to improve the service life of the focus ring and at the same time improve the etching uniformity of the wafer.

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

[0008] The etching component of the present invention includes: An electrostatic chuck having a placement table, and the placement table has a wafer placement position for placing a wafer; A focus ring disposed on the electrostatic chuck and arranged around the placement table. A gas channel is provided in the focus ring, and the gas channel has an air inlet and an air outlet. The air inlet is used for introducing gas, and the air outlet faces the wafer placement position; A gas supply component connected to the air inlet for supplying inert gas and / or reactive gas to the air inlet to control the etching rate of the wafer edge.

[0009] Further, the gas channel includes a plurality of branch channels, there are a plurality of air outlets, and they are evenly arranged at intervals in the circumferential direction of the wafer placement position, and the branch channels correspond to the air outlets one by one.

[0010] Further, an overflow ring groove arranged around the wafer placement position is further provided on the focusing ring, the opening of the overflow ring groove faces the wafer placement position, and a plurality of the air outlets are evenly arranged at intervals in the circumferential direction on the groove bottom of the overflow ring groove.

[0011] Further, there is one air inlet, a plurality of the branch channels share one air inlet, and the travel distances between the plurality of air outlets and the air inlet are all equal.

[0012] Further, there are a plurality of air inlets, a plurality of the branch channels are divided into multiple groups, each group of the branch channels includes at least one of the branch channels and shares one air outlet.

[0013] Further, there are multiple groups of the gas supply assemblies, and each group of the gas supply assemblies corresponds to one air inlet.

[0014] Further, there are multiple layers of the gas channels, each layer of the gas channels is used to introduce different types of gases, and the multiple layers of the gas channels are communicated with each other.

[0015] Further, a flared structure is provided at the air outlet.

[0016] Further, 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 the reaction gas; pressure regulating valves, flow meters and inlet valves are provided on both the inert gas branch and the reaction gas branch.

[0017] Further, 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. The first ring piece and the second ring piece are attached to each other so that the first channel groove and the second channel groove enclose the gas channel.

[0018] The present invention also provides an etching method, including: Fixing a wafer on a placement table of an electrostatic chuck; Introducing inert gas into the back of the wafer through an air path in the electrostatic chuck; Adjusting the etching rate of the wafer edge by introducing inert gas and / or reaction gas into the edge of the wafer through the gas channel on the focusing ring.

[0019] Further, when the etching rate at the edge of the wafer is higher than the standard etching rate of the plastic, at least one of the following three measures is adopted: increasing the flow rate of the inert gas, decreasing the flow rate of the reactive gas, and decreasing the temperature of the inert gas and the reactive gas; when the etching rate at the edge of the wafer is lower than the standard etching rate of the plastic, at least one of the following three measures is adopted: decreasing 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.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects: By providing a gas channel in the focus ring and using a gas supply assembly to accurately supply an inert gas and / or a reactive gas to the edge region of the wafer, the present application can directly affect the etching environment in the edge region, thereby affecting the reaction rate between the wafer and the reactive gas, and further realizing dynamic regulation of the etching rate at the edge of the wafer. This design breaks through the limitation of the traditional focus ring that only controls edge etching by physical properties, and provides a more flexible and accurate etching control method. The present application can accurately control the etching conditions in the edge region without affecting the etching of the central region of the wafer. This local regulation method not only improves the etching uniformity of the wafer, but also extends the service life of the focus ring, reduces frequent replacement caused by edge effects, and reduces the production cost of the wafer. If the setting method of the present application is not adopted and only edge etching is controlled by physical properties, it 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 lead to frequent replacement of the focus ring, increasing the production cost of the wafer. Description of the Drawings

[0021] Figure 1 Schematic structural diagram of an embodiment of the etching assembly (gas supply assembly not shown) of the present invention; Figure 2 is Figure 1 Schematic structural diagram of the focus ring of the etching assembly in Figure 3 is Figure 1 Schematic structural diagram of an embodiment when the focus ring of the etching assembly in Figure 4 is Figure 1 Partial structural schematic diagram of an embodiment when the focus ring of the etching assembly in Figure 5 is Figure 1 Schematic connection diagram of the gas supply assembly and the focus ring of the etching assembly in

[0022] Reference Signs: 1, electrostatic chuck; 2. Focusing ring; 3. Wafer; 4. Gas channel; 5. Inlet; 6. Outlet; 7. First sealing ring; 8. Second sealing ring; 9. First blow air pipeline; 10. First area; 11. Second blow air pipeline; 12. Second area; 13. Branch channel; 14. Overflow ring groove. Specific embodiments

[0023] The etching component and etching method of the present invention will be described below with reference to the schematic diagrams, in which the preferred embodiments of the present invention are shown. It should be understood that those skilled in the art can modify the present invention described herein while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as a broad guidance for those skilled in the art and not as a limitation on the present invention.

[0024] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. And the "connection" and "coupling" mentioned in this application, unless otherwise specified, both include direct and indirect connection (coupling). In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0025] In the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0026] The present invention will be described more specifically by way of example in the following paragraphs with reference to the drawings. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are all in a very simplified form and use non-precise scales, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0027] The inventors' research found that in a typical semiconductor etching process, the wafer is placed on an electrostatic chuck and surrounded by a focus ring. When the etching process begins, due to insufficient temperature control in the edge region, there may be a significant difference in the etching rate between this region and the central region of the wafer, thus affecting the etching uniformity. In addition, due to the lack of precise means for controlling the edge etching rate, engineers often have to frequently replace the focus ring, even though these focus rings may still have some remaining useful life.

[0028] When solving the problem of controlling the etching rate at the wafer edge, this application first considered the limitations in the prior art. Traditional methods mainly rely on the physical properties of the focus ring to control edge etching, but this method lacks flexibility and precision. Therefore, this application began to explore new methods that can dynamically adjust the wafer edge environment.

[0029] A preliminary idea was to affect the etching rate in the edge region by adjusting the temperature of the electrostatic chuck. However, this method is difficult to achieve precise control and may affect the temperature distribution of the entire wafer. Another consideration was to change the material or structure of the focus ring, but this may increase costs and be difficult to adapt to different etching processes.

[0030] In further thinking, this application noticed the important role of gas in the etching process. From this, an innovative idea emerged: to regulate the etching rate by precisely controlling the gas environment in the wafer edge region. Specifically, gas channels can be set in the focus ring, and specific gases can be introduced into the wafer edge region through these channels.

[0031] The advantage of this method lies in its flexibility and precision. By adjusting the type, flow rate, and temperature of the gas, dynamic control of the etching environment can be achieved. For example, introducing an inert gas can reduce the etching rate, while increasing the reactive gas can increase the etching rate. This method can not only solve the edge effect problem but also be adjusted in real time according to different etching requirements.

[0032] Based on this idea, this application further improved the technical solution. To achieve precise control of the gas, a gas supply component needs to be designed, which can provide different types of gases and precisely control their flow rates and temperatures. At the same time, the design of the focus ring also needs to be adjusted accordingly to accommodate the gas channels and ensure that the gas can effectively act on the wafer edge region.

[0033] After repeated thinking and optimization, this application finally formed the design of a new type of etching component. This design includes an electrostatic chuck, an improved focus ring, and a dedicated gas supply component. The electrostatic chuck provides a stable platform for placing the wafer, the improved focus ring is provided with gas channels, and the gas supply component is responsible for providing precisely controlled gas to these channels.

[0034] Accordingly, the present application proposes an etching component, as Figure 1 and Figure 2 shown, including an electrostatic chuck 1, a focusing ring 2 and a gas supply component. Among them, the electrostatic chuck 1 has a placement table, and the placement table has a wafer placement position for placing a wafer 3; the focusing ring 2 is arranged on the electrostatic chuck 1 and surrounds the placement table. A gas channel 4 is provided in the focusing ring 2. The gas channel 4 has an air inlet 5 and an air outlet 6. The air inlet 5 is used for introducing gas, and the air outlet 6 faces the wafer placement position; the gas supply component is connected to the air inlet 5 and is used to supply inert gas and / or reactive gas to the air inlet 5 to regulate the etching rate of the edge of the wafer 3.

[0035] Among them, the electrostatic chuck 1 refers to a device for fixing the wafer 3, and specifically can be realized by a planar structure made of ceramic material. The focusing ring 2 refers to an annular structure surrounding the electrostatic chuck 1, and specifically can be made of silicon material, and its shape matches the outer contour of the electrostatic chuck 1. The gas channel 4 refers to a passage for gas flow provided inside the focusing ring 2, including an air inlet 5 and an air outlet 6. The air inlet 5 is located on the outside or bottom of the focusing ring 2 and is used to connect the gas supply component. The air outlet 6 faces the position of the wafer 3 on the wafer placement position to ensure that the gas can directly act on the edge area of the wafer 3, and specifically can be realized by means of internal grooving or drilling. The gas supply component is connected to the air inlet 5 of the focusing ring 2. A device for providing inert gas and reactive gas, specifically can be realized by a gas storage tank, pipelines and control valves, etc. By precisely controlling the type, flow rate, pressure and temperature of the gas, the dynamic adjustment of the etching environment at the edge of the wafer 3 can be realized.

[0036] By providing the gas channel 4 in the focusing ring 2 and using the gas supply component to precisely supply inert gas and / or reactive gas to the edge area of the wafer 3, the present application can directly affect the etching environment in the edge area, thereby affecting the reaction rate between the wafer 3 and the reactive gas, and further realizing the dynamic regulation of the etching rate of the edge of the wafer 3. This design breaks through the limitation of the traditional focusing ring that only relies 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 area without affecting the etching of the central area of the wafer 3. This local regulation 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 focusing ring 2, reduces the frequent replacement caused by edge effects, and reduces the production cost of the wafer 3. If the setting method of the present application is not adopted and only the edge etching is controlled by physical properties, it will lead to poor etching uniformity of the wafer 3, reduce the surface quality, interface quality and electrical performance reliability of the wafer 3. In addition, it will also lead to the need for frequent replacement of the focusing ring, increasing the production cost of the wafer 3.

[0037] In actual operation, when it is detected that the etching rate at the edge of the wafer 3 is too fast, at least one of the following three measures can be adopted: increasing the flow rate of the inert gas, decreasing the flow rate of the reaction gas, and decreasing the temperature of the inert gas and the reaction gas, so as to reduce the etching rate in the edge region. On the contrary, when the edge etching rate is too slow, at least one of the following three measures can be adopted: decreasing 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, so as to increase the etching rate. This method allows for rapid adjustment according to the real-time monitoring results, ensuring the uniformity of the etching process.

[0038] In some of these 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 placement table of the electrostatic chuck 1, and the diameter of the first sealing ring 7 is smaller than that of the second sealing ring 8. The wafer 3 is placed on the first sealing ring 7 and the second sealing ring 8. The electrostatic chuck 1 is further provided with a first air blowing pipeline 9 and a second air blowing pipeline 11. The first air blowing pipeline 9 is used to blow gas into the first region 10 formed by the first sealing ring 7, and the second air blowing pipeline 11 is used to blow gas into the second region 12 formed by the second sealing ring 8. The gases blown by the first air blowing pipeline 9 and the second air blowing pipeline 11 are used to control the temperature of the wafer 3. According to the process requirements, the gas blown 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.

[0039] In some of these embodiments, in order to make the gas distribution in the gas channel 4 more uniform, the gas channel 4 includes a plurality of branch channels 13. There are a plurality of air outlets 6, which are evenly spaced along the circumference of the wafer placement position, and the branch channels 13 correspond to the air outlets 6 one by one.

[0040] The setting of the multiple air outlets 6 increases the distribution points of gas output, which helps the gas to cover the edge region of the wafer 3 more evenly. The air outlets 6 are evenly spaced along the circumference of the placement table, ensuring the uniform distribution of gas at the edge of the wafer 3 and avoiding the situation of insufficient or excessive gas supply in some areas. This design of uniform distribution can effectively reduce the etching non-uniformity in the edge region 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 air outlets 6 are not evenly spaced along the circumference, it will cause the gas to be unevenly distributed at the edge of the wafer 3, resulting in insufficient or excessive gas supply in some areas, making the uniformity of the etching process poor and reducing the surface quality, interface quality and electrical performance reliability of the wafer 3.

[0041] In some of these embodiments, a flared structure is provided at the gas outlet 6. By gradually increasing the cross-sectional area of the flow channel, the flared structure can reduce the gas flow rate, change the gas from concentrated jetting to diffused flow, avoid the concentrated impact of the air 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, it will cause the air flow to concentrate on a certain point and the gas cannot be evenly distributed, resulting in different etching rates at different positions, thus affecting the uniformity of the etching process and reducing the surface quality, interface quality and electrical performance reliability of the wafer 3.

[0042] Preferably, the flared structure is a trumpet-shaped flare or a conical flare. In other embodiments, the flared structure may also be other gradually expanding structures, such as a semi-elliptical shape.

[0043] In some of these embodiments, as Figure 3 shown, an overflow ring groove 14 is further provided on the focusing ring 2 and arranged around the placement position of the wafer 3. The opening of the overflow ring groove 14 faces the wafer placement position, and a plurality of the gas outlets 6 are arranged at equal intervals in the circumferential direction on the bottom of the overflow ring groove 14.

[0044] Since a plurality of the gas outlets 6 are arranged at equal intervals in the circumferential direction on the bottom of the overflow ring groove 14, the gas flowing out from the gas outlet 6 first enters the overflow ring groove 14. After the gas fills the overflow ring groove 14, it can overflow evenly in the circumferential direction, so that the gas can cover 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.

[0045] Preferably, a flared structure is provided at the gas outlet 6 at the bottom of the overflow ring groove 14. By gradually increasing the cross-sectional area of the flow channel, the flared structure can reduce the gas flow rate, change the gas from concentrated jetting to diffused flow, so that the gas can be more evenly distributed and filled in the overflow ring groove 14. In this way, the uniformity of the gas overflow will be better. Therefore, the overflow ring groove 14 and the flared structure at the gas outlet 6 can cooperate synergistically to further improve the etching uniformity of the edge area of the wafer 3, and further improve the accuracy and consistency of the etching process. If the overflow ring groove 14 is not provided and only the gas outlets 6 are arranged in a multi-point distribution form, the gas distribution may still be uneven, and the etching uniformity cannot be further improved, nor can the surface quality, interface quality and electrical performance reliability of the wafer 3 be further improved.

[0046] In other embodiments, as Figure 4As shown, the gas channel 4 has multiple layers, and each layer of the gas channel 4 is used to introduce different types of gases, and the multiple layers of the gas channel 4 are connected to each other.

[0047] Specifically, by designing multiple gas paths inside the focusing ring, it is convenient to introduce gases with different temperatures or different types into the gas paths of different layers respectively. For example, two layers of gas paths are set, and the inner gas channel 4 is used to introduce reaction gases, and the outer gas channel 4 is used to introduce inert gases. For another example, three layers of gas channels 4 can also be set. Among them, the inner gas channel 4 is used to introduce reaction gases, the middle gas channel 4 is used to introduce inert gases, and the outer gas channel 4 is used to introduce specially treated gases, such as gases treated by microwave plasma, for further precisely controlling the etching reaction.

[0048] This multi-layer structural design can be achieved by setting multiple partition layers inside the silicon focusing ring. Each partition layer has an independent gas inlet 5 and an outlet 6, and the gas channels 4 of each layer are connected through set channels to achieve the orderly flow and mixing of gases, thereby being able to further precisely control the etching reaction, 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 multi-layer structural design is not adopted, it will be difficult to accurately control the flow sequence of gases, and thus it will be impossible to further precisely control the etching reaction, and it will not be possible to further improve the surface quality, interface quality, and electrical performance reliability of the wafer 3. In some of the embodiments, one gas inlet 5 is provided, and multiple branch channels 13 share one gas inlet 5, and the travel distances between multiple outlets 6 and the gas inlet 5 are all equal.

[0049] Since the travel distances between all the outlets 6 and the gas inlet 5 are equal, the resistance suffered by the gas during the flow process is also basically the same. This ensures that the gas can be evenly distributed to each outlet 6, thereby forming a uniform gas distribution at the edge of the wafer 3. The uniform gas distribution is crucial for regulating the etching rate at the edge of the wafer 3, can effectively improve the etching uniformity at the edge of the wafer 3, and further improves the surface quality, interface quality, and electrical performance reliability of the wafer 3. If the travel distances between the outlets 6 and the gas inlet 5 are not equal, it will cause the gas to not be evenly distributed to each outlet 6, and thus it will not be evenly distributed at the edge of the wafer 3, and it will not be possible to further uniformly etch the edge of the wafer 3, and it will not be possible to further improve the surface quality, interface quality, and electrical performance reliability of the wafer 3.

[0050] Such as Figure 2As shown, taking the focusing ring 2 with eight air outlets 6 as an example, after the air outlet 6 extends into the interior of the focusing ring 2, it divides into two, then two divides into four, and four divides into eight, thus forming eight branch channels 13 with equal travel distances. In other embodiments, other numbers of branch channels 13 can also be set according to requirements, such as 16 or 32.

[0051] In some 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.

[0052] Specifically, the design of multiple air inlets 5 provides more entry points for gas supply. Each air inlet 5 can be independently controlled, so that the supply quantity and type of gas can be adjusted according to the requirements of different regions.

[0053] Furthermore, the design of dividing the branch channels 13 into multiple groups and sharing one air outlet 6 for each group realizes fine control of gas distribution. This layout allows for more precise adjustment of the gas supply to different regions at the edge of the wafer 3. For example, according to the etching conditions at different positions on the edge of the wafer 3, the etching rate can be balanced by adjusting the gas flow rate in the corresponding group of branch channels 13.

[0054] As a preferred implementation manner, there can be multiple groups of gas supply components, and each group of gas supply components corresponds to one air inlet 5. This configuration further enhances the independent control ability of each air inlet 5. Each group of gas supply components can independently adjust the gas type, flow rate, and temperature of its corresponding air inlet 5, so as to achieve more precise etching control. If only one group of gas supply components is used, it will be impossible to independently control each air inlet 5, and thus it will be impossible to accurately control the gas type, flow rate, and temperature of the corresponding air inlet 5.

[0055] For example, in a specific embodiment, the etching component can be provided with four air inlets 5, which are respectively located at the four quadrant positions of the focusing ring 2. Each air inlet 5 is connected to three branch channels 13, and these three branch channels 13 are located in the same quadrant and each is provided with one air outlet 6. Four groups of gas supply components are respectively connected to the four air inlets 5. In actual operation, according to the etching conditions of different regions at the edge of the wafer 3, the etching rate can be balanced by adjusting the parameters of the corresponding gas supply components.

[0056] 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 flow rate of the inert gas at the corresponding gas inlet 5 of this quadrant or by reducing the flow rate of the reaction gas. Of course, the temperature of the inert gas or the reaction gas can also be reduced. On the contrary, if the etching rate at the edge of a certain quadrant is too low, the reaction gas flow rate can be increased or the inert gas flow rate can be reduced to increase the etching rate. Of course, the temperature of the inert gas or the reaction gas can also be increased. In this way, a more uniform etching effect can be achieved at the edge of the wafer 3.

[0057] In one embodiment, as Figure 5 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 gas inlet 5, the reaction gas branch is used to introduce reaction gas into the gas inlet 5, and the heating element is used to heat the inert gas and / or the reaction gas; pressure regulating valves, flow meters, and inlet valves are provided on both the inert gas branch and the reaction gas branch.

[0058] The inert gas branch can use a variety of inert gases, such as argon, helium, or nitrogen. The reaction gas branch can select a suitable reaction gas according to the specific etching process, such as fluorine gas, chlorine gas, or other active gases. The heating element can be an electric heating wire, an infrared heating lamp, or other heating devices.

[0059] The inert gas branch and the reaction gas branch can be independently controlled, and the etching rate can be affected by adjusting their respective flow rates, ratios, or temperatures. The heating element can heat both gases simultaneously or separately, thereby further affecting the etching rate through temperature adjustment.

[0060] Specifically, the pressure regulating valve can dynamically adjust the gas pressure according to the requirements of different etching stages to ensure that the gas enters the system at the optimal pressure. The flow meter monitors the gas flow rate in real time and feeds the data back to the control system, enabling the system to timely adjust the gas supply volume. The inlet valve can precisely control the opening and closing time of the gas, achieving precise timing control of the gas supply, which is beneficial to improving the etching uniformity of the wafer 3, as well as improving the surface quality, interface quality, and electrical performance reliability of the wafer 3. If the inert gas branch, the reaction gas branch, the heating element, and the corresponding pressure regulating valve, flow meter, and inlet valve are not separately provided, precise timing control of the supply volume, supply speed, and stability of the inert gas and the reaction gas cannot be achieved.

[0061] For example, on the inert gas branch, a precision pressure regulating valve can be adopted, with a pressure regulation range of 0 - 100 kPa and an accuracy of up to ±0.1 kPa. A mass flowmeter can be selected for the flowmeter, with a measurement range of 0 - 1000 sccm and an accuracy of up to ±1%. A solenoid valve with fast response can be selected for the intake valve, with a response time of less than 50 ms. These parameters can be adjusted according to actual requirements.

[0062] On the reactive gas branch, a similar configuration can be adopted, but materials with stronger corrosion resistance need to be selected according to the characteristics of the reactive gas. For example, a fully metal-sealed pressure regulating valve can be selected for the pressure regulating valve, a corrosion-resistant mass flowmeter can be selected for the flowmeter, and a solenoid valve with a corrosion-resistant coating can be selected for the intake valve.

[0063] By setting these control elements on the two gas branches respectively, the operator can independently adjust the pressure, flow rate, and supply timing of each gas. This design not only improves the controllability and accuracy of the etching process but also enables flexible adjustment of gas supply parameters according to different etching requirements, contributing to improving etching uniformity and product quality.

[0064] As a preferred implementation, 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 rate ratio, pressure value, and supply timing of the inert gas and reactive gas can be preset. In actual operation, the operator only needs to select the corresponding recipe, and the system will automatically adjust each control element to achieve the optimal gas supply state. This not only simplifies the operation process but also improves the etching efficiency and etching consistency of the wafer 3.

[0065] In addition, the technical solution of the present application helps to optimize the gas usage efficiency. By precisely controlling the gas supply, unnecessary waste of inert gas and reactive gas can be reduced, thereby reducing the production cost of the wafer. For example, the supply quantity and time of the gas can be precisely controlled according to actual requirements to avoid waste caused by excessive gas supply.

[0066] In one of the embodiments, 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. 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.

[0067] Specifically, by dividing the focusing ring 2 into two ring pieces and setting channel grooves on their respective surfaces, it is easier to machine the complex gas channel 4 structure. This design not only simplifies the manufacturing process but also improves the accuracy and consistency of the gas channel 4. When the two ring pieces are fitted together, the formed gas channel 4 can supply gas to the edge of the wafer 3 more uniformly, thereby more effectively regulating the etching rate.

[0068] Furthermore, this split design also facilitates the maintenance and replacement of the focusing ring 2. When it is necessary to clean or replace the gas channel 4, the two ring pieces can be easily separated, the channel grooves can be cleaned. If one of the ring pieces is damaged, a new ring piece can be replaced. After cleaning or replacement, the two ring pieces are reassembled into the focusing ring 2 again, which greatly improves the maintainability and service life of the focusing ring 2. If the manufacturing method of the non-split design focusing ring 2 is adopted, it will increase the processing difficulty and manufacturing cost of the focusing ring, and it is also inconvenient for subsequent maintenance and replacement.

[0069] As a preferred implementation manner, the first ring piece and the second ring piece can be made of the same or different materials. For example, ceramic materials or special alloy materials with high temperature resistance and corrosion resistance can be selected. The first channel groove and the second channel groove can be fabricated by precision machining techniques such as numerical control milling or laser etching to ensure the accuracy and surface finish of the channels.

[0070] In practical applications, the first ring piece and the second ring piece can be fixed by bolt connection or snap-fit structure. To ensure airtightness, a sealing ring can be set or sealant can be coated on the contact surface of the two ring pieces. The cross-section of the gas channel 4 can be designed as circular, elliptical or other suitable shapes to optimize the gas flow characteristics.

[0071] Through this design, the manufacturing of the gas channel 4 becomes simpler and more precise. Only a shallow groove needs to be machined on each ring piece. Compared with machining complex internal channels on the overall focusing ring 2, the manufacturing difficulty and cost are greatly reduced. At the same time, since the channel is composed of two ring pieces, it is easier to inspect and clean, improving the convenience of maintenance.

[0072] This application also provides an etching method, including: S100: Fix the wafer on the placement table of the electrostatic chuck; S200: Pass an inert gas into the back of the wafer through the gas path in the electrostatic chuck; S300: Regulate the etching rate of the wafer edge by passing an inert gas and / or a reactive gas into the edge of the wafer through the gas channel on the focusing ring.

[0073] Specifically, in step S100, it can be achieved by means of electrostatic force or mechanical clamping, etc. During the fixing process, it is necessary to ensure uniform contact between the wafer and the placement table to avoid local stress concentration.

[0074] In step S200, an air 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, nitrogen, etc., and the specific choice depends on the requirements of the etching process. The gas flow rate 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, precise control of the overall temperature distribution of the wafer can be achieved, and thus the uniformity of the etching rate can be affected.

[0075] In step S300, by controlling the type and amount of gas introduced, the etching rate at the edge of the wafer can be directly affected. The gas channels on the focus ring can be designed in a circular structure, with multiple air outlets evenly distributed along the edge of the wafer. Only one inlet can be set, and the air outlet also has uniform air output; multiple inlets can also be set, and each inlet can be independently controlled to achieve fine adjustment of the etching rate in different regions of the wafer.

[0076] Furthermore, in order to control the etching rate at the edge of the wafer, when the etching rate at the edge of the wafer 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, decreasing the flow rate of the reactive gas, and decreasing the temperature of the inert gas and the reactive gas; when the etching rate at the edge of the wafer is lower than the standard etching rate, at least one of the following three measures is adopted: decreasing 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.

[0077] The etching method of the present application can be implemented by the etching component in any one of the above technical solutions.

[0078] The etching method of the present application solves the problem of controlling the etching rate at the wafer edge by introducing a controllable gas flow in the wafer edge region. 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 affecting the reaction rate between the wafer and the reactive gas, and further realizing the control of the etching rate. The advantage of this method is that it can adjust the etching parameters in real time and dynamically, improving the flexibility and precision of the etching process. The present application can precisely control the etching conditions in the edge region without affecting the etching of the wafer center region. This local control method not only improves the etching uniformity of the wafer, but also improves the surface quality, interface quality, and electrical performance reliability of the wafer. At the same time, it 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 the setting method of the present application is not adopted and only the physical properties are relied on to control the edge etching, it 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 lead to the need for frequent replacement of the focus ring, increasing the production cost of the wafer.

[0079] 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 also intends to include these changes and modifications.

Claims

1. An etching component, characterized in that, Comprising: An electrostatic chuck having a placement table with a wafer placement position for placing a wafer; A focus ring disposed on the electrostatic chuck and arranged around the placement table. A gas channel is provided in the focus ring, the gas channel having an air inlet and an air outlet. The air inlet is used for introducing a gas, and the air outlet faces the wafer placement position; A gas supply assembly connected to the air inlet for supplying an inert gas and / or a reactive gas to the air inlet to regulate the etching rate of the wafer edge.

2. The etching component according to claim 1, wherein The gas channel includes a plurality of branch channels, and there are a plurality of air outlets which are evenly spaced circumferentially along the wafer placement position. The branch channels correspond to the air outlets one by one.

3. The etching component according to claim 2, characterized in that, An overflow ring groove arranged around the wafer placement position is further provided on the focus ring. The opening of the overflow ring groove faces the wafer placement position, and a plurality of the air outlets are evenly spaced circumferentially at the bottom of the overflow ring groove.

4. The etching component according to claim 2, wherein There is one air inlet, and a plurality of the branch channels share one air inlet, and the travel distances between the plurality of air outlets and the air inlet are all equal.

5. The etching component according to claim 2, wherein There are a plurality of air inlets, and the plurality of branch channels are divided into multiple groups. Each group of branch channels includes at least one branch channel and shares one air outlet.

6. The etching component according to claim 5, wherein There are multiple groups of the gas supply assemblies, and each group of the gas supply assemblies corresponds to one air inlet.

7. The etching component according to claim 1, characterized in that The gas channel has multiple layers, and each layer of the gas channel is used for introducing different types of gases, and the multiple layers of the gas channels are connected.

8. The etching component according to any one of claims 1-7, characterized in that, A flaring structure is provided at the air outlet.

9. The etching component according to claim 1, characterized in that The gas supply assembly includes an inert gas branch, a reactive gas branch and a heating element. The inert gas branch is used for introducing an inert gas into the air inlet, the reactive gas branch is used for introducing a reactive gas into the air inlet, and the heating element is used for heating the inert gas and / or the reactive gas; pressure regulating valves, flow meters and inlet valves are provided on both the inert gas branch and the reactive gas branch.

10. The etching component according to claim 1, characterized in that, The focus 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. The first ring piece and the second ring piece are attached to each other so that the first channel groove and the second channel groove enclose the gas channel.

11. An etching method, characterized in that, Comprising: Fixing the wafer on the placement table of the electrostatic chuck; Introducing an inert gas into the back of the wafer through the gas path in the electrostatic chuck; Introducing an inert gas and / or a reactive gas into the edge of the wafer through the gas channel on the focus ring to regulate the etching rate of the wafer edge.

12. The etching method according to claim 11, wherein, 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, decreasing the flow rate of the reactive gas, and decreasing 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 decreasing 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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