Wafer plasma etching equipment

Abstract

The embodiment of the invention provides wafer plasma etching equipment which comprises the components of a heating stage on which a wafer is placed, and a plurality of gas feed-in holes which are arranged at the circumferential edge of the heating stage; the pipeline assembly is used for introducing gas into the plurality of gas feed-in holes; and the adjusting mechanism can adjust the speed and / or the amount of gas blown to the wafer by the plurality of gas feed-in holes, so that a flow field above the wafer is changed. A plurality of gas feed-in holes are formed in the circumferential edge of a heating stage, a pipeline assembly introduces gas into the gas feed-in holes, the gas is blown to a wafer through the gas feed-in holes, a gas flow field above the wafer can be changed, the speed or the quantity of the gas blown to the wafer through the gas feed-in holes is adjusted through an adjusting mechanism, and therefore the gas flow field can be changed. The influence range of the gas can be controlled, so that the gas flow field above the wafer can be adjusted, and the etching uniformity of the wafer is ensured.

Description

Technical Field

[0001] The present specification relates to the field of plasma etching technology, and in particular to a wafer plasma etching device. Background Art

[0002] In the plasma etching process in semiconductor processing, the WAFER (wafer) often needs to be temperature controlled during the etching process. Generally, a hot plate (with higher temperature and lower cost) is used for temperature control and heating. At present, ordinary hot plates only have heating function. Although the heating is relatively uniform, there is a lack of effective adjustment means when the gas flow field in the cavity is uneven, making it difficult to control the etching rate and etching shape of the inner and outer areas of the WAFER (wafer). Summary of the invention

[0003] In view of this, an embodiment of the present specification provides a wafer plasma etching device, by opening a plurality of gas feeding holes at the circumferential edge of the hot platform, a pipeline assembly introduces gas into the gas feeding holes, and the gas is blown toward the wafer through the gas feeding holes, so that the gas flow field above the wafer can be changed. The gas speed or gas amount blown toward the wafer through the gas feeding holes can be adjusted by an adjustment mechanism, and the influence range of the gas can be controlled, thereby achieving the adjustment of the gas flow field above the wafer and ensuring the uniformity of wafer etching.

[0004] The embodiments of this specification provide the following technical solutions: a wafer plasma etching device, comprising: A heating platform, the wafer is placed on the heating platform, and a plurality of gas feeding holes are opened at the circumferential edge of the heating platform; A pipeline assembly, the pipeline assembly is used to introduce gas into the plurality of gas feed holes; The regulating mechanism can regulate the gas velocity and / or gas volume blown toward the wafer from the plurality of gas feeding holes, so as to change the flow field above the wafer.

[0005] Preferably, the adjusting mechanism includes a cover plate and a lifting mechanism, the cover plate includes a lifting portion and an adjusting portion, the lifting portion and the adjusting portion are integrally formed, the adjusting portion at least partially extends above the gas feeding hole, the lifting portion is connected to the lifting mechanism, and the lifting mechanism drives the lifting portion to move so that the adjusting portion moves toward or away from the gas feeding hole.

[0006] Preferably, a gas feeding interval is formed between the adjusting portion and the circumferential edge of the heating platform, and when the adjusting portion moves toward or away from the gas feeding hole, the size of the gas feeding interval changes.

[0007] Preferably, the lifting part is arranged around the heating platform, and at least a part of the inner wall of the lifting part is in contact with the outer wall of the heating platform.

[0008] Preferably, the lifting mechanism includes one of an electric cylinder, a pneumatic cylinder, a ball screw, and an electromagnetic integrated guide rail.

[0009] Preferably, a receiving groove is provided on the top of the heating platform, and the receiving groove is used to place the wafer. A transition surface is formed between the receiving groove and the edge of the heating platform, and the transition surface is an inclined surface.

[0010] Preferably, a plurality of special-shaped through holes are formed on the transition surface, and the special-shaped through holes are respectively connected to the plurality of gas feeding holes.

[0011] Preferably, the pipeline assembly includes a main pipeline and a plurality of branch pipelines, the first end of the main pipeline passes through the hot stage and is connected to an external gas supply system, the second end of the main pipeline is connected to the plurality of branch pipelines, and the plurality of branch pipelines are respectively connected to the plurality of gas feed holes.

[0012] Preferably, the external air supply system includes two supply modes: constant inlet pressure or constant outlet flow.

[0013] Preferably, a plurality of gas feeding holes are provided, and the plurality of gas feeding holes are evenly distributed on the hot stage.

[0014] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above technical solutions adopted in the embodiments of this specification include at least: By opening a plurality of gas feeding holes at the circumferential edge of the hot stage, a pipeline assembly introduces gas into the gas feeding holes, and the gas is blown toward the wafer through the gas feeding holes, the gas flow field above the wafer can be changed, and the gas speed or gas volume blown toward the wafer through the gas feeding holes can be adjusted by an adjusting mechanism, and the influence range of the gas can be controlled, thereby adjusting the gas flow field above the wafer and ensuring the uniformity of wafer etching. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a schematic diagram of the plasma etching gas flow field in the prior art; Figure 2 It is a structural schematic diagram of a wafer plasma etching device provided by the present application; Figure 3 It is a schematic diagram of the structure of a hot stage of a wafer plasma etching device provided by the present application; Figure 4 It is a schematic diagram of the gas flow field distribution of the wafer plasma etching equipment provided by the present application; Figure 5 It is a top view of the hot stage of the wafer plasma etching equipment provided in the present application.

[0017] In the figure, 1, heating platform; 2, cover plate; 21, adjustment part; 22, lifting part; 3, gas feeding hole; 4, transition surface; 5, special-shaped through hole; 6, wafer; 7, main pipeline; 8, branch pipeline; 9, lifting mechanism. DETAILED DESCRIPTION

[0018] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0019] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0020] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0021] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0022] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0023] Plasma etching is a common process in semiconductor processing. The temperature of WAFER is often required in the etching process. There are two common temperature control methods: 1. The electrostatic chuck is heated by helium gas and the hot plate is directly heated.

[0024] 2. The hot plate (with higher temperature and lower cost) is used for temperature-controlled heating.

[0025] However, at present, ordinary hot plates only have heating function. Although the heating is relatively uniform, there is a lack of effective adjustment means when facing the uneven gas flow field in the cavity. This will cause uneven distribution of gas molecules, effective etching particles, ions, etc. near the center and edge positions of the wafer during processing, resulting in different etching rates and etching morphologies.

[0026] The technical solutions provided by various embodiments of the present application are described below in conjunction with the accompanying drawings.

[0027] like Figure 2-Figure 5 As shown, a wafer plasma etching device comprises: A heat stage 1, on which the wafer 6 is placed, and a plurality of gas feeding holes 3 are provided at the circumferential edge of the heat stage 1; A pipeline assembly, the pipeline assembly is used to introduce gas into the plurality of gas feeding holes 3; The regulating mechanism can regulate the gas velocity and / or gas volume blown from the gas feeding holes 3 to the wafer 6 so as to change the flow field above the wafer 6 .

[0028] By opening a plurality of gas feeding holes 3 at the circumferential edge of the heat platform 1, the pipeline assembly introduces gas into the gas feeding holes 3, and the gas is blown toward the wafer 6 through the gas feeding holes 3, the gas flow field above the wafer 6 can be changed, and the gas speed or gas amount blown toward the wafer 6 through the gas feeding holes 3 can be adjusted by the adjustment mechanism, and the influence range of the gas can be controlled, thereby realizing the adjustment of the gas flow field above the wafer 6 and ensuring the uniformity of the etching of the wafer 6.

[0029] It should be noted that the gas introduced into the gas feeding hole 3 through the pipeline assembly can be a process gas, a dilution gas, or a mixed gas, which can adjust the concentration of reactive ions in the outer area of ​​the wafer 6 or adjust the thickness of the protective layer on the etching side wall. The etching effect on the wafer 6 can be adjusted by changing the gas type, the gas speed or the gas amount blown to the wafer 6 through the gas feeding hole 3.

[0030] It should also be noted that when the gas is blown toward the wafer 6 through the gas feed hole 3, it will affect the outer area of ​​the wafer 6 to form an affected area. The size of the affected area will be affected by the gas outlet speed and the gas volume. The size of the affected area can be adjusted by the gas outlet speed or the gas volume.

[0031] like Figure 1 The flow field shown is a rough schematic diagram of the flow field in the prior art, which will cause uneven distribution of gas molecules, effective etching particles, ions, etc. near the center and edge of the wafer 6 during processing, resulting in different etching rates and etching morphologies. Figure 4 As shown, it is a flow field diagram of the present application. Due to the existence of the gas feeding hole 3, gas can be blown into the edge area of ​​the wafer 6, so that the gas molecules, effective etching particles, ions, etc. are evenly distributed, thereby achieving uniform etching rate.

[0032] like Figure 2-Figure 4 As shown, in some embodiments, the adjustment mechanism includes a cover plate 2 and a lifting mechanism 9, the cover plate 2 includes a lifting portion 22 and an adjustment portion 21, the lifting portion 22 and the adjustment portion 21 are integrally formed, the adjustment portion 21 at least partially extends to the top of the gas feeding hole 3, the lifting portion 22 is connected to the lifting mechanism 9, the lifting mechanism 9 drives the lifting portion 22 to move, so that the adjustment portion 21 moves toward or away from the gas feeding hole 3, the lifting mechanism 9 drives the lifting portion 22 to move, so that the adjustment portion 21 moves toward or away from the gas feeding hole 3, the lifting mechanism 9 drives the cover plate 2 to move, so that the cover plate 2 can move along the axial direction of the hot stage 1, the adjustment portion 21 of the cover plate 2 at least partially extends to the top of the gas feeding hole 3, when the lifting mechanism 9 drives the adjustment portion 21 to move through the lifting portion 22, the adjustment portion 21 moves toward or away from the top of the hot stage 1, so that the distance between the adjustment portion 21 and the gas feeding hole 3 changes.

[0033] It should be noted that the cross section of the cover plate 2 is in the shape of a letter "7", the adjustment portion 21 is arranged horizontally, and the lifting portion 22 is arranged vertically.

[0034] like Figure 2 and Figure 4As shown, in some embodiments, a gas feeding interval is formed between the adjusting portion 21 and the circumferential edge of the hot stage 1. When the adjusting portion 21 moves toward or away from the gas feeding hole 3, the size of the gas feeding interval changes. The adjusting portion 21 extends above the gas feeding hole 3. A gas feeding interval is formed between the adjusting portion 21 and the circumferential edge of the top of the hot stage 1. When the lifting mechanism 9 drives the adjusting portion 21 to move toward or away from the gas feeding hole 3, the distance between the adjusting portion 21 and the top of the hot stage 1 changes, so that the size of the gas feeding interval changes. By changing the size of the gas feeding interval, the gas velocity or gas amount can be changed, thereby changing the etching rate of the outer area of ​​the wafer 6.

[0035] like Figure 2 and Figure 4 As shown, in some embodiments, the lifting portion 22 is arranged around the heat platform 1, and the inner wall of the lifting portion 22 is at least partially in contact with the outer wall of the heat platform 1. The inner wall of the lifting portion 22 is in contact with the outer wall of the heat platform 1, which can prevent the gas blown out of the gas feeding hole 3 from dissipating to the outside of the heat platform 1, and ensure that the gas can be vertically directed to the wafer 6.

[0036] It should be noted that, in this embodiment, the lifting part 22 is in sliding sealing contact with the heat stage 1. In other embodiments, other arrangements may be used, as long as the lifting part 22 and the heat stage 1 are sealed and the lifting part 22 can move in the vertical direction relative to the heat stage 1.

[0037] like Figure 4 As shown, in some embodiments, the lifting mechanism 9 includes one of an electric cylinder, a pneumatic cylinder, a ball screw, and an electromagnetic integrated guide rail. In this embodiment, the lifting mechanism 9 is an electric cylinder, and the telescopic end of the electric cylinder is connected to the lifting part 22. In other embodiments, the lifting mechanism 9 can also be one of a pneumatic cylinder, a ball screw, and an electromagnetic integrated guide rail, and it is sufficient to ensure that the lifting mechanism 9 can drive the lifting part 22 to perform lifting motion.

[0038] like Figure 2-Figure 4 As shown, in some embodiments, a receiving groove is provided on the top of the heat platform 1, and the receiving groove is used to place the wafer 6. A transition surface 4 is formed between the receiving groove and the edge of the heat platform 1, and the transition surface 4 is an inclined surface. By providing a receiving groove on the top of the heat platform 1 and forming an inclined transition surface 4 between the receiving groove and the edge of the heat platform 1, the center of the receiving groove is on the axis line of the heat platform 1, thereby ensuring that the wafer 6 is at the center position of the top of the heat platform 1 when it falls.

[0039] like Figure 2-Figure 4As shown, in some embodiments, a plurality of special-shaped through holes 5 are provided on the transition surface 4, and the plurality of special-shaped through holes 5 are respectively connected with the plurality of gas feeding holes 3. By providing the special-shaped through holes 5 connected with the gas feeding holes 3 on the transition surface 4, part of the gas in the gas feeding holes 3 can be vertically directed to the wafer 6 through the special-shaped through holes 5. The special-shaped through holes 5 are located obliquely above the accommodating groove, which can raise the height of the gas outlet and facilitate further feeding of the gas into the wafer 6.

[0040] like Figure 4 As shown, in some embodiments, the pipeline assembly includes a main pipeline 7 and several branch pipelines 8, the first end of the main pipeline 7 passes through the hot platform 1 and is connected to the external gas supply system, the second end of the main pipeline 7 is connected to the several branch pipelines 8, and the several branch pipelines 8 are respectively connected to the several gas feeding holes 3, the main pipeline 7 extends to the outside of the hot platform 1 and is connected to the external gas supply system, the external gas supply system supplies gas to the main pipeline 7, the gas in the main pipeline 7 flows into the several branch pipelines 8 respectively, the gas in the several branch pipelines 8 flows into the corresponding gas feeding holes 3 respectively, and then flows out through the top of the gas feeding hole 3 and blows to the wafer 6.

[0041] In some embodiments, the external air supply system includes two supply modes: constant inlet pressure or constant outlet flow. The air supply mode is divided into two air intake modes: front-end UPC or MFC, which are adjusted by adjusting the size of the opening (i.e., the distance between the adjustment part 21 and the hot stage 1). The two modes have different adjustment effects: UPC: Control the inlet pressure to be constant. When the opening is increased, the air resistance is reduced, and the outlet velocity and gas volume are increased.

[0042] MFC: Control the outlet flow rate to be constant, increase the opening, that is, increase the outlet area. At this time, the outlet volume is constant and the gas velocity per unit area will decrease.

[0043] like Figure 2-Figure 3 As shown, in some embodiments, the gas feeding holes 3 are provided with a plurality of holes, and the plurality of gas feeding holes 3 are evenly distributed on the heat stage 1. By providing a plurality of gas feeding holes 3, and the plurality of gas feeding holes 3 are evenly distributed in a circular shape at the edge of the heat stage 1, it is possible to ensure that the gas blows evenly on the heat stage 1, so that the area affected by the gas on the wafer 6 is a continuous and uniform ring, as shown in FIG. Figure 5 As shown, Figure 5 The inner shaded area is the area where the gas affects the wafer 6 .

[0044] The same or similar parts between the various embodiments in this specification can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the method embodiment described later, since it corresponds to the system, the description is relatively simple, and the relevant parts can be referred to the partial description of the system embodiment.

[0045] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A wafer plasma etching device, characterized in that: include: A heating platform, the wafer is placed on the heating platform, and a plurality of gas feeding holes are opened at the circumferential edge of the heating platform; A pipeline assembly, the pipeline assembly is used to introduce gas into the plurality of gas feed holes, the pipeline assembly comprises a main pipeline and a plurality of branch pipelines, a first end of the main pipeline passes through the hot stage and is connected to an external gas supply system, a second end of the main pipeline is connected to the plurality of branch pipelines, and the plurality of branch pipelines are respectively connected to the plurality of gas feed holes; The regulating mechanism can regulate the gas velocity and / or gas volume blown toward the wafer from the plurality of gas feeding holes so as to change the flow field above the wafer. The regulating mechanism comprises a cover plate and a lifting mechanism. The cover plate comprises a lifting portion and an regulating portion. The regulating portion at least partially extends above the gas feeding holes. The lifting portion is connected to the lifting mechanism. The lifting mechanism drives the lifting portion to move so as to move the regulating portion toward or away from the gas feeding holes.

2. The wafer plasma etching equipment according to claim 1, characterized in that: The lifting part and the adjusting part are integrally formed.

3. The wafer plasma etching equipment according to claim 1, characterized in that: A gas feeding interval is formed between the adjusting portion and the peripheral edge of the heating platform. When the adjusting portion moves toward or away from the gas feeding hole, the size of the gas feeding interval changes.

4. The wafer plasma etching equipment according to claim 1, characterized in that: The lifting part is arranged around the heating platform, and at least a part of the inner wall of the lifting part is in contact with the outer wall of the heating platform.

5. The wafer plasma etching equipment according to claim 1, characterized in that: The lifting mechanism includes one of an electric cylinder, a pneumatic cylinder, a ball screw, and an electromagnetic integrated guide rail.

6. The wafer plasma etching equipment according to any one of claims 1 to 5, characterized in that: A receiving groove is provided on the top of the heating platform, and the receiving groove is used to place the wafer. A transition surface is formed between the receiving groove and the edge of the heating platform, and the transition surface is an inclined surface.

7. The wafer plasma etching equipment according to claim 6, characterized in that: The transition surface is provided with a plurality of special-shaped through holes, and the special-shaped through holes are respectively connected with the plurality of gas feeding holes.

8. The wafer plasma etching equipment according to claim 1, characterized in that: The external air supply system includes two supply modes: constant inlet pressure or constant outlet flow.

9. The wafer plasma etching equipment according to claim 1, characterized in that: A plurality of gas feeding holes are provided, and the plurality of gas feeding holes are evenly distributed on the hot stage.

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