Device for improving etching uniformity of wafer surface
By designing a multi-radio frequency generator and metal conductive coil in a dry etching machine, the problem of unevenness of wafer etching caused by gas flow is solved, and the uniform distribution of plasma energy is achieved, which significantly improves the wafer surface etching Uniformity.
Patent Information
- Application Number
- CN202421668068.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-15
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2034-07-15
AI Technical Summary
During the wafer etching process of existing dry etching machines, due to the influence of gas flow, there are too many etching at the center and too few etching at the edge, which affects the etching uniformity. The existing optimization solution has limited effect.
Design a device that includes a vacuum sealing cavity, upper, lower and side radio frequency generators, and metal conductive coils. The edge of the wafer is bombarded through the side radio frequency generator and metal conductive coils to ensure uniform distribution of plasma energy, combined with The helical distribution of the upper metal conductive coil and adjustable guide rail unit adjust the bonding area and concentration of the plasma and wafer surface.
It effectively improves the uniformity of wafer surface etching, ensures consistent plasma distribution at the center and edges, and improves etching quality.
Smart Images
Figure CN222281920U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a device for etching a wafer surface in the semiconductor field, in particular to a device for improving the uniformity of etching the wafer surface. Background Art
[0002] In semiconductor wafer production, dry etching machines are core process players. Their main function is to dry-etch the wafers after they have been coated, photolithographically processed, and developed, so that the required pattern is formed on the surface of the wafer. Dry etching uses plasma to etch the material.
[0003] In the semiconductor field, the existing dry etching machine voltage source design can achieve rapid chemical and physical reactions between plasma and wafer surface materials. However, due to the influence of gas flow, after the wafer is etched, the center is etched more than the edge, resulting in a thinner center and thicker edge, which affects the etching uniformity. The usual solution is to adjust the current of the upper metal coil to optimize the etching uniformity, but the degree of optimization is limited. Summary of the invention
[0004] The utility model provides a device for improving the etching uniformity of a wafer surface, which can improve the etching uniformity of the wafer surface.
[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions:
[0006] A device for improving the etching uniformity of a wafer surface, the device comprising: a vacuum-sealed cavity, an upper radio frequency generator, a lower radio frequency generator, a side radio frequency generator, a side metal conductive coil, an upper metal conductive coil and a carrier, wherein the carrier is located in the cavity, the upper radio frequency generator is connected to the upper metal conductive coil, and the upper metal conductive coil is located above the cavity; the lower radio frequency generator is located below the cavity and is connected to the carrier through a wire; the side metal conductive coil is connected to the inner wall of the cavity through a guide rail unit, and the side metal conductive coil is connected to the side radio frequency generator located outside the cavity.
[0007] As a preferred example, the carrier is used to hold wafers.
[0008] As a preferred example, the side metal conductive coil and the wafer are located on the same horizontal plane, or the side metal conductive coil is located above the wafer.
[0009] As a preferred example, the side metal conductive coil is one turn or two turns.
[0010] As a preferred example, the upper metal conductive coils are distributed in a spiral manner and are located on the same horizontal plane; the upper metal conductive coils are directly opposite to the top surface of the supporting platform.
[0011] As a preferred example, the guide rail unit includes a vertical guide rail, a slider, a fastener and a snap-on, the vertical guide rail is fixedly connected to the inner wall of the cavity, the slider is connected to the vertical guide rail via a fastener, the snap-on is fixedly connected to the slider, and the side metal conductive coil is connected to the snap-on.
[0012] As a preferred example, the fastener and the vertical guide rail are detachably connected, and the side metal conductive coil can move up and down along the vertical guide rail.
[0013] As a preferred example, the number of the guide rail units is two or three, and they are evenly arranged on the inner wall of the cavity along the circumferential direction.
[0014] As a preferred example, one side of the slider is connected to the vertical guide rail, the other side of the slider is opposite to the support platform, the buckle is connected to the other side of the slider, and the buckle opening of the buckle faces the support platform.
[0015] Compared with the prior art, the device of the utility model can improve the etching uniformity of the wafer surface. The device of the utility model comprises a cavity, an upper radio frequency generator, a lower radio frequency generator, a side radio frequency generator, an upper metal conductive coil, a side metal conductive coil and a carrier, wherein the side metal conductive coil is fixed on the inner wall of the cavity, and the side metal conductive coil is connected to the side radio frequency generator located outside the cavity. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a schematic diagram of the structure of an embodiment of the utility model;
[0017] Figure 2 It is a top view of the upper metal conductive coil in the embodiment of the utility model.
[0018] The figure includes: a cavity 1, an upper RF generator 2, a lower RF generator 3, a side RF generator 4, a side metal conductive coil 5, an upper metal conductive coil 6, a carrier 7, and a wafer 8. DETAILED DESCRIPTION
[0019] The technical solution of the utility model is described in detail below in conjunction with the accompanying drawings.
[0020] like Figure 1As shown, a device for improving the uniformity of wafer surface etching according to an embodiment of the utility model comprises: a vacuum-sealed chamber 1, an upper RF generator 2, a lower RF generator 3, a side RF generator 4, a side metal conductive coil 5, an upper metal conductive coil 6 and a carrier 7. The carrier 7 is located in the chamber 1. The upper RF generator 2 is connected to the upper metal conductive coil 6, and the upper metal conductive coil 6 is located above the chamber 1. The lower RF generator 3 is located below the chamber 1 and is connected to the carrier 7 through a wire. The side metal conductive coil 5 is connected to the inner wall of the chamber 1 through a guide rail unit, and the side metal conductive coil 5 is connected to the side RF generator 4 located outside the chamber 1. The carrier 7 is used to hold a wafer 8. The chamber 1 is filled with a reactive gas, such as argon.
[0021] When the device of the above embodiment is working, the wafer 8 is first placed on the carrier 7. Under a vacuum environment, after the reaction gas flows into the cavity 1, the upper RF generator 2, the lower RF generator 3 and the side RF generator 4 are started. When the upper RF generator 2 is turned on, the reaction gas in the cavity 1 is bombarded to form a plasma. The reaction gas located in the middle of the wafer 8 is bombarded more, and the reaction gas located at the edge of the wafer 8 is bombarded less. When the lower RF generator 3 is turned on, a downward bias energy is applied to the plasma, so that the plasma quickly falls to the surface of the wafer 8, allowing the plasma to react chemically and physically with the surface material of the wafer 8 to form the desired process pattern. When the side RF generator 4 is turned on, the side metal conductive coil 5 bombards the reaction gas located at the edge of the wafer 8. This ensures that the reaction gas located in the middle of the wafer 8 or at the edge of the wafer 8 can be bombarded to form a plasma with a relatively uniform distribution.
[0022] When the wafer 8 undergoes a wafer reaction in the cavity 1, by setting the side RF generator 4 and the side metal conductive coil 5, the problem of less etching at the edge of the wafer 8 can be solved and the uniformity of wafer etching can be improved. The reaction gas at the edge of the wafer 8 can obtain the same energy as that at the center of the wafer. In this way, no matter how the reaction gas flows inside the cavity, there will be energy to bombard it, thereby improving the concentration uniformity of the plasma inside the cavity. The plasma can fall evenly on the surface of the wafer 8, so that the center and edge of the wafer 8 obtain basically the same plasma, so that the etching uniformity of the surface of the wafer 8 can be improved. The side metal conductive coil 5 can move up and down along the guide rail unit. By changing the height of the side metal conductive coil 5, the bonding area between the plasma and the edge of the wafer and the concentration falling at the edge of the wafer can be adjusted.
[0023] Preferably, the side metal conductive coil 5 and the wafer 8 are located on the same horizontal plane, or the side metal conductive coil 5 is located above the wafer 8. If the side metal conductive coil 5 is placed below the wafer 8, the plasma formed after the side metal conductive coil 5 bombards the reaction gas will not fall around the wafer 8.
[0024] Preferably, the side metal conductive coil 5 is one or two turns. The side metal conductive coil 5 can also be set with multiple turns. Different numbers of turns are set, and different forces are applied to the plasma in the cavity 1. By controlling the signal size of the side RF generator 4, different forces can also be applied to the plasma in the cavity 1.
[0025] In order to allow more plasma to react with the wafer 8, preferably, Figure 2 As shown, the upper metal conductive coil 6 is distributed in a spiral shape and is located on the same horizontal plane; the upper metal conductive coil 6 is directly opposite to the top surface of the carrier 7. The upper metal conductive coil 6 is distributed in a spiral shape, and the middle conductive coil is larger than the periphery, so that more plasma etches the middle of the wafer 8 and less plasma etches the periphery of the wafer 8.
[0026] In order to adjust the energy generated by the side metal conductive coil 5 to the plasma, preferably, the guide rail unit is located in the cavity 1, and the guide rail unit includes a vertical guide rail, a slider, a fastener and a snap-fit. The vertical guide rail is fixedly connected to the inner wall of the cavity 1, the slider is connected to the vertical guide rail through a fastener, the snap-fit is fixedly connected to the slider, and the side metal conductive coil 5 is connected to the snap-fit.
[0027] In this preferred embodiment, the position of the side metal conductive coil 5 is adjusted vertically. Specifically, the snap-fit piece is fixedly connected to the slider. In the vertical guide rail, the slider is moved up and down so that the slider is located at a preset position, and then the slider is fixed to the vertical guide rail by a fastener. The fastener and the vertical guide rail are detachably connected. The fastener can be a bolt, and a vertical groove is opened on the vertical guide rail. A through hole is provided on the slider. The bolt passes through the through hole and the vertical groove of the slider. The bolt can move in the vertical groove. The two ends of the bolt are fastened to the surface of the slider and the back of the vertical guide rail by nuts, respectively, so as to achieve the positioning of the slider. The side metal conductive coil 5 is installed on the snap-fit piece. According to the process requirements, the position of the side metal conductive coil 5 is adjusted in the up and down direction along the vertical guide rail, so as to change the relative height of the side metal conductive coil 5 and the wafer, so as to adjust the bonding area between the plasma and the edge of the wafer and the concentration falling at the edge of the wafer.
[0028] In order to make the position of the side metal conductive coil 5 more stable and secure, preferably, the guide rail units are two or three and are evenly arranged along the circumference on the inner wall of the cavity 1. Through two-point or three-point positioning, the side metal conductive coil 5 will not separate from the inner wall of the cavity 1 during operation.
[0029] Preferably, one side of the slider is connected to the vertical guide rail, the other side of the slider is opposite to the carrier 7, the buckle is connected to the other side of the slider, and the buckle opening of the buckle faces the carrier 7. In this way, after the side metal conductive coil 5 is installed on the buckle, the inner wall of the side metal conductive coil 5 faces the carrier 7, which is conducive to applying energy to the plasma.
[0030] The above shows and describes the basic principles, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above specific embodiments. The above specific embodiments and the description in the specification are only for further illustrating the principles of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the claims and their equivalents.
Claims
1. A device for improving the uniformity of wafer surface etching, characterized in that: The device comprises: a vacuum-sealed cavity (1), an upper radio frequency generator (2), a lower radio frequency generator (3), a side radio frequency generator (4), a side metal conductive coil (5), an upper metal conductive coil (6) and a support platform (7), wherein: The support platform (7) is located in the cavity (1); the upper radio frequency generator (2) is connected to the upper metal conductive coil (6); the upper metal conductive coil (6) is located above the cavity (1); the lower radio frequency generator (3) is located below the cavity (1) and is connected to the support platform (7) via a wire; the side metal conductive coil (5) is connected to the inner wall of the cavity (1) via a guide rail unit, and the side metal conductive coil (5) is connected to the side radio frequency generator (4) located outside the cavity (1).
2. The device according to claim 1, characterized in that The carrier platform (7) is used to hold the wafer (8).
3. The device according to claim 2, characterized in that The side metal conductive coil (5) and the wafer (8) are located on the same horizontal plane, or the side metal conductive coil (5) is located above the wafer (8).
4. The device according to claim 1, characterized in that The side metal conductive coil (5) has one or two turns.
5. The device according to claim 1, characterized in that The upper metal conductive coils (6) are distributed in a spiral manner and are located on the same horizontal plane; the upper metal conductive coils (6) are directly opposite to the top surface of the supporting platform (7).
6. The device according to claim 1, characterized in that The guide rail unit comprises a vertical guide rail, a slider, a fastener and a snap-fit piece; the vertical guide rail is fixedly connected to the inner wall of the cavity (1); the slider is connected to the vertical guide rail via the fastener; the snap-fit piece is fixedly connected to the slider; and the side metal conductive coil (5) is connected to the snap-fit piece.
7. The device according to claim 6, characterized in that The fastener and the vertical guide rail are detachably connected, and the side metal conductive coil (5) can move up and down along the vertical guide rail.
8. The device according to claim 6, characterized in that The guide rail units are two or three in number and are evenly arranged on the inner wall of the cavity (1) along the circumferential direction.
9. The device according to claim 6, characterized in that One side of the slider is connected to the vertical guide rail, the other side of the slider is opposite to the bearing platform (7), the buckle is connected to the other side of the slider, and the buckle opening of the buckle faces the bearing platform (7).