A reaction chamber device and working method thereof

Abstract

A reaction chamber device and a working method thereof, the reaction chamber device comprising: a reaction chamber body; a wafer carrying platform located in the reaction chamber body, the surface of the wafer carrying platform being suitable for placing wafers; an upper buffer ring surrounding the wafer carrying platform; a lower buffer ring located at the bottom of the upper buffer ring and surrounding the wafer carrying platform; and a plurality of discrete height adjusters located at the bottom of the lower buffer ring, the plurality of discrete height adjusters being suitable for adjusting the longitudinal distances of different regions between the lower buffer ring and the upper buffer ring. The reaction chamber device can improve the uniformity and symmetry of the wafer surface reaction.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing, and in particular to a reaction chamber device and a working method thereof. Background Art

[0002] In semiconductor manufacturing, multiple processes are involved, and each process is completed by certain equipment and processes. Among them, plasma reactions are often used for chemical and physical deposition, etching, and photoresist ashing removal of semiconductor wafers and other substrates. Commonly used plasma sources include ICP, CCP, and microwave generation methods. For some photoresist ashing removal processes, it is usually not desirable for high-energy ions in the plasma to directly interact with the photoresist, but rather it is expected that a high-temperature ashing reaction will occur between the chemically active free radical intermediates in the plasma and the photoresist. This reaction is a typical high-temperature chemical reaction process. Generally, the uniformity of the ashing reaction is crucial, and this uniformity depends on the uniformity of the distribution of chemically active free radical intermediates (referred to as active groups) on the surface of the wafer, including the uniformity of the active group flow, pressure, and composition.

[0003] Generally speaking, photoresists with high implant concentrations often use reducing chemical reactions in the removal process, such as using H2 / N2 mixtures as reaction gases. This ashing reaction often shows a strong trend of high center reaction rate and low edge reaction rate. The reason is that the high density H generated by the plasma * The active groups have a very high migration speed due to their light weight. * The residence time in the reaction chamber is very short and it is very easy to be drawn out by the vacuum pump, resulting in H at the edge of the wafer. * The trend of a steep drop in concentration, i.e., high concentration at the center of the wafer and fast ashing reaction, and low concentration at the edge of the wafer and slow ashing reaction, leads to poor overall reaction uniformity.

[0004] This poor reaction uniformity will lead to a more sensitive asymmetry problem. Specifically, the following factors will lead to H * There is a serious asymmetry in the distribution of active groups on the wafer surface. 1) The asymmetry of the design of the plasma generator and the plasma chamber makes the distribution of plasma inside the chamber asymmetric; 2) The processing and installation of the isolation grid may cause H * The distribution of active groups after passing through the isolation grid to the wafer surface is asymmetric; 3) the vertical spacing between the wafer and the isolation grid is asymmetric; 4) the vacuum pump in the cavity has an asymmetric structure, which makes the vacuum pump have asymmetric effect on H * The pumping effect of the active groups is asymmetric, which seriously affects the H * The symmetry of the distribution of active groups on the wafer surface, especially in the wafer edge area. Summary of the invention

[0005] The problem solved by the present invention is to provide a reaction chamber device and a working method thereof, which can improve the uniformity and symmetry of the reaction on the surface of a wafer.

[0006] In order to solve the above technical problems, the present invention provides a reaction chamber device, comprising: a reaction chamber body; a wafer carrying platform located in the reaction chamber body, the surface of the wafer carrying platform is suitable for placing wafers; an upper buffer ring surrounding the wafer carrying platform; a lower buffer ring located at the bottom of the upper buffer ring and surrounding the wafer carrying platform; and a plurality of discrete height adjusters located at the bottom of the lower buffer ring, the plurality of discrete height adjusters being suitable for adjusting the longitudinal distance between the lower buffer ring and different areas of the upper buffer ring.

[0007] Optionally, the upper buffer ring is spaced from the inner wall of the reaction chamber body; the lower buffer ring is spaced from the wafer supporting platform; and the projection of the upper buffer ring on the bottom surface of the reaction chamber body and the projection of the lower buffer ring on the bottom surface of the reaction chamber body have an overlapping area.

[0008] Optionally, the upper buffer ring is a solid structure, and the lower buffer ring is a solid structure.

[0009] Optionally, the material of the upper buffer ring is quartz, ceramic, bare aluminum or anodized aluminum; the material of the lower buffer ring is quartz, ceramic, bare aluminum or anodized aluminum.

[0010] Optionally, it also includes: a height adjustment controller, wherein the height adjustment controller is suitable for controlling the height adjuster to adjust the height.

[0011] Optionally, the number of the height adjusters is more than 3.

[0012] Optionally, the number of the height adjusters is 4.

[0013] Optionally, it also includes: an inductively coupled radio frequency unit located above the reaction chamber body; an isolation grid is arranged on the top of the reaction chamber body; the inductively coupled radio frequency unit is located above the isolation grid; and an air outlet passes through the bottom wall of the reaction chamber body.

[0014] The present invention also provides a working method of a reaction chamber device, comprising: placing a wafer on the surface of the wafer supporting platform and performing a first process reaction; during the first process reaction, using the plurality of height adjusters to adjust the longitudinal distances of different areas between the lower buffer ring and the upper buffer ring, so that the upper buffer ring and the lower buffer ring extend the path of the reaction source particles moving laterally outward along the wafer surface.

[0015] Optionally, the reaction chamber device further comprises: a height adjustment controller; and the working method of the reaction chamber device further comprises: using the height adjustment controller to respectively control the plurality of height adjusters to perform height adjustment.

[0016] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0017] The reaction chamber device provided by the technical solution of the present invention comprises a wafer carrying platform located in the reaction chamber body, the surface of the wafer carrying platform is suitable for placing wafers; an upper buffer ring surrounding the wafer carrying platform; and a lower buffer ring located at the bottom of the upper buffer ring and surrounding the wafer carrying platform; the upper buffer ring and the lower buffer ring are suitable for extending the path of the reaction source particles moving laterally outward along the surface of the wafer, thereby enhancing the reaction rate of the edge area of ​​the wafer, and adjusting the distance of the overlapping area of ​​the upper buffer ring and the lower buffer ring by adjusting the longitudinal distance between the lower buffer ring and the upper buffer ring, thereby adjusting the pumping speed of the reaction source particles in the reaction chamber body by the exhaust system of the reaction chamber body, for example, for H * The pumping speed of the group is increased, thereby optimizing the uniformity of the reaction rate on the entire surface of the wafer. The plurality of discrete height adjusters are suitable for adjusting the longitudinal distances of different regions between the lower buffer ring and the upper buffer ring, that is, each height adjuster can independently adjust the height, so that the longitudinal distances of different regions between the lower buffer ring and the upper buffer ring can be different, which is used to compensate for the asymmetry of the distribution of the reaction source particles on the wafer surface.

[0018] The working method of the reaction chamber device provided by the technical solution of the present invention is to place the wafer on the surface of the wafer supporting platform and then perform the first process reaction; in the process of performing the first process reaction, the plurality of height adjusters are used to adjust the longitudinal distances of different areas between the lower buffer ring and the upper buffer ring, and the upper buffer ring and the lower buffer ring extend the path of the reaction source particles moving laterally outward along the wafer surface. The upper buffer ring and the lower buffer ring are suitable for extending the path of the reaction source particles moving laterally outward along the wafer surface, so as to enhance the reaction rate of the edge area of ​​the wafer, and the distance of the overlapping area of ​​the upper buffer ring and the lower buffer ring is regulated by adjusting the longitudinal distance between the lower buffer ring and the upper buffer ring, thereby adjusting the pumping speed of the reaction source particles in the reaction chamber body by the exhaust system of the reaction chamber body, for example, for H * The pumping speed of the group is increased, thereby optimizing the uniformity of the reaction rate on the entire surface of the wafer. The plurality of discrete height adjusters are suitable for adjusting the longitudinal distances of different regions between the lower buffer ring and the upper buffer ring, that is, each height adjuster can independently adjust the height, so that the longitudinal distances of different regions between the lower buffer ring and the upper buffer ring can be different, which is used to compensate for the asymmetry of the distribution of the reaction source particles on the wafer surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic cross-sectional structure diagram of a reaction chamber device in one embodiment of the present invention;

[0020] Figure 2 It is a schematic diagram of the structure of an upper buffer ring, a lower buffer ring and a height adjuster in one embodiment of the present invention;

[0021] Figure 3 It is a schematic diagram of a height adjuster adjusting a plurality of lower buffer rings in one embodiment of the present invention. DETAILED DESCRIPTION

[0022] An embodiment of the present invention provides a reaction chamber device, please refer to Figure 1 and Figure 2 ,include:

[0023] Reaction chamber body 100;

[0024] A wafer carrying platform 110 located in the reaction chamber body 100 , wherein the surface of the wafer carrying platform 110 is suitable for placing the wafer 10 ;

[0025] Surrounding the upper buffer ring 150a of the wafer carrying platform 110;

[0026] A lower buffer ring 150b located at the bottom of the upper buffer ring 150a and surrounding the wafer carrying platform 110;

[0027] A plurality of discrete height adjusters 150c are located at the bottom of the lower buffer ring 150b, and the plurality of discrete height adjusters 150c are suitable for adjusting the longitudinal distance between different areas of the lower buffer ring 150b and the upper buffer ring 150a.

[0028] In this embodiment, the wafer supporting platform 110 has a plurality of displacement holes penetrating the wafer supporting platform 110 ; ejector pins (not shown) are respectively located in the displacement holes, and the ejector pins are suitable for supporting the wafer 10 , so that the wafer 10 is placed on the surface of the wafer supporting platform 110 by the ejector pins moving downward in the displacement holes.

[0029] In this embodiment, the reaction chamber device is a plasma reaction device. The reaction chamber device can perform an ashing reaction.

[0030] The reaction chamber device further includes: an inductively coupled radio frequency unit located above the reaction chamber body 100; the inductively coupled radio frequency unit includes: a reaction chamber medium tube 120; and a radio frequency antenna 140 distributed on the reaction chamber medium tube side 120.

[0031] The reaction chamber device further includes: a gas outlet C penetrating through the bottom wall of the reaction chamber body 100 .

[0032] In this embodiment, the upper buffer ring 150 a contacts the wafer carrying platform 110 , and the upper buffer ring 150 a is spaced apart from the inner wall of the reaction chamber body 100 .

[0033] In this embodiment, the lower buffer ring 150 b is spaced apart from the wafer carrying platform 110 .

[0034] In this embodiment, the projection of the upper buffer ring 150a on the bottom surface of the reaction chamber body 100 and the projection of the lower buffer ring 150b on the bottom surface of the reaction chamber body 100 have an overlapping area. The upper buffer ring 150a and the lower buffer ring 150b are suitable for extending the path of the reaction source particles moving laterally outward along the surface of the wafer 10.

[0035] An isolation grid 130 is disposed on the top of the reaction chamber body 100 ; the inductively coupled radio frequency unit is located above the isolation grid 130 .

[0036] The top of the reaction chamber medium tube 120 is provided with a gas inlet 121 .

[0037] The radio frequency antenna 140 excites the gas in the medium pipe 120 of the reaction chamber to generate plasma, and the charged particles (including ions) in the plasma are filtered out by the isolation grid 130, and the chemically active groups in the plasma freely pass through the isolation grid 130 into the reaction chamber body 100 to reach the surface of the wafer 10, and then perform a high-temperature ashing reaction with the photoresist on the surface of the wafer 10. After the high-temperature ashing reaction, the wafer 10 is adjusted to the wafer transfer position by the ejector pin and then transferred out.

[0038] For photoresists with high implant concentrations, reducing chemical reactions are often used in the removal process. For example, a H2 / N2 mixture is used as the reaction gas. The high-density H generated by the plasma * The active groups have very high migration speed due to their light weight.

[0039] In this embodiment, the upper buffer ring 150a is a solid structure and is made of quartz, ceramic, bare aluminum or anodized aluminum.

[0040] In this embodiment, the lower buffer ring 150b is a solid structure. The material of the lower buffer ring 150b is quartz, ceramic, bare aluminum or anodized aluminum.

[0041] The reaction chamber device further includes: a height adjustment controller 160, and the height adjustment controller 160 is suitable for controlling the height adjuster 150c to adjust the height.

[0042] In one embodiment, the number of the height adjusters 150c is 3 or more.

[0043] In a specific embodiment, the number of the height adjusters 150c is 4. In other embodiments, the number of the height adjusters 150c can be other numbers without limitation.

[0044] In this embodiment, each height adjuster 150c is evenly distributed at the bottom of the lower buffer ring 150b. In other embodiments, each height adjuster 150c is unevenly distributed at the bottom of the lower buffer ring 150b.

[0045] In this embodiment, the reaction chamber device further includes: an equipment controller 170 .

[0046] Correspondingly, an embodiment of the present invention also provides a working method of a reaction chamber device, comprising the following steps: after placing the wafer 10 on the surface of the wafer supporting platform 110, performing a first process reaction; during the first process reaction, using the plurality of height adjusters 150c to adjust the longitudinal distance between different areas of the lower buffer ring 150b and the upper buffer ring 150a, the upper buffer ring 150a and the lower buffer ring 150b extend the path of the reaction source particles moving laterally outward along the wafer surface.

[0047] By adjusting the longitudinal distance between the lower buffer ring 150b and the upper buffer ring 150a, the distance between the upper buffer ring 150a and the lower buffer ring 150b in the overlapping area is regulated, thereby adjusting the pumping speed of the reaction source particles in the reaction chamber body 100 by the pumping system of the reaction chamber body 100, for example, for H * The pumping speed of the group is increased, thereby optimizing the uniformity of the reaction rate on the entire surface of the wafer 10.

[0048] The upper buffer ring 150 a and the lower buffer ring 150 b are suitable for extending the path of the reaction source particles moving laterally outward along the surface of the wafer 10 .

[0049] The working method of the reaction chamber device further includes: using the height adjustment controller 160 to respectively control the plurality of height adjusters 150c to adjust the height.

[0050] Specifically, a wafer is provided, and a photoresist layer is provided on the surface of the wafer. After the wafer is placed on the surface of the wafer supporting platform 110, the wafer supporting platform 110 heats the wafer, and the temperature of the wafer is rapidly heated from room temperature to a reaction temperature (eg, about 280°C). At the same time, the RF antenna 140 excites the gas in the medium pipe 120 of the reaction chamber to generate plasma, and the charged particles (including ions) in the plasma will be filtered out by the isolation grid 130, and the chemically active groups in the plasma will freely pass through the isolation grid 130 into the reaction chamber body 100 to reach the surface of the wafer 10 and undergo a high-temperature ashing reaction with the photoresist on the surface of the wafer 10. During the high-temperature ashing reaction, the equipment controller 170 evaluates the uniformity and asymmetry of the ashing reaction, calculates the height and direction that the lower buffer ring 150b needs to be adjusted, and then feeds back to the height adjustment controller 160. The height adjustment controller 160 controls several height adjusters 150c to adjust the height and direction of the lower buffer ring 150b, thereby achieving synchronous adjustment of the symmetry and uniformity of the ashing reaction rate distribution; after completing the high-temperature ashing reaction for a specific time, the wafer 10 is adjusted to the wafer transfer position by the ejector pin and then transferred out.

[0051] In this embodiment, taking four height adjusters 150c as an example, the height of the lower buffer ring 150b can be anisotropically adjusted by the independent height adjusters 150c, that is, the spacing between the upper and lower buffer rings 150b is adjusted to a non-uniform state (refer to Figure 3 ), the area with small spacing corresponds to the slow H * The group pumping speed is used to compensate for the slow ashing reaction rate in the initial state. The area with large spacing corresponds to the fast H * The group pumping speed is used to compensate for the fast ashing reaction rate in the initial state, thereby optimizing the symmetry of the reaction rate distribution.

[0052] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A reaction chamber device, characterized in that: include: Reaction chamber body; A wafer carrying platform located in the reaction chamber body, wherein the surface of the wafer carrying platform is suitable for placing wafers; an upper buffer ring surrounding the wafer carrying platform; a lower buffer ring located at the bottom of the upper buffer ring and surrounding the wafer carrying platform; A plurality of discrete height adjusters located at the bottom of the lower buffer ring, the plurality of discrete height adjusters being suitable for adjusting the longitudinal distances of different regions between the lower buffer ring and the upper buffer ring; The upper buffer ring is spaced from the inner side wall of the reaction chamber body; the lower buffer ring is spaced from the wafer carrying platform; the projection of the upper buffer ring on the bottom surface of the reaction chamber body and the projection of the lower buffer ring on the bottom surface of the reaction chamber body have an overlapping area; It also includes: a height adjustment controller and a device controller electrically connected to each other, wherein the height adjustment controller is electrically connected to each of the height adjusters respectively; The device controller is suitable for evaluating the uniformity and asymmetry of the ash reaction rate distribution, and calculating the height and direction of the lower buffer ring that need to be adjusted based on the evaluation results, and then feeding it back to the height adjustment controller; the height adjustment controller controls each height adjuster to perform anisotropic height adjustment on the lower buffer ring according to the height and direction that need to be adjusted, so that the spacing between the upper buffer ring and the lower buffer ring is uneven in each direction, thereby achieving synchronous adjustment of the uniformity and symmetry of the ash reaction rate distribution.

2. The reaction chamber device according to claim 1, characterized in that: The upper buffer ring is a solid structure, and the lower buffer ring is a solid structure.

3. The reaction chamber device according to claim 1, characterized in that: The material of the upper buffer ring is quartz, ceramic, bare aluminum or anodized aluminum; the material of the lower buffer ring is quartz, ceramic, bare aluminum or anodized aluminum.

4. The reaction chamber device according to claim 1, characterized in that: The number of the height adjusters is 3 or more.

5. The reaction chamber device according to claim 4, characterized in that: The number of the height adjusters is 4.

6. The reaction chamber device according to claim 1, characterized in that: Also includes: an inductively coupled radio frequency unit located above the reaction chamber body; An isolation grid is disposed on the top of the reaction chamber body; the inductive coupling radio frequency unit is located above the isolation grid; A gas outlet runs through the bottom wall of the reaction chamber body.

7. A method for operating a reaction chamber device according to any one of claims 1 to 6, characterized in that: include: After placing the wafer on the surface of the wafer carrying platform, performing a first process reaction; During the first process reaction, the plurality of height adjusters are used to adjust the longitudinal distances between the lower buffer ring and the upper buffer ring in different areas, so that the upper buffer ring and the lower buffer ring extend the path of the reaction source particles moving laterally outward along the wafer surface; The reaction chamber device also includes: a height adjustment controller, which is electrically connected to the equipment controller; the working method of the reaction chamber device also includes: using the height adjustment controller to be electrically connected to each of the height adjusters respectively, and controlling each of the height adjusters to adjust the height; the equipment controller is suitable for evaluating the uniformity and asymmetry of the ashing reaction rate distribution, and calculating the height and direction of the lower buffer ring that need to be adjusted according to the evaluation results, and then feeding it back to the height adjustment controller; the height adjustment controller controls each of the height adjusters to perform anisotropic height adjustment on the lower buffer ring according to the height and direction that need to be adjusted, so that the distance between the upper buffer ring and the lower buffer ring is uneven in each direction, thereby realizing synchronous adjustment of the uniformity and symmetry of the ashing reaction rate distribution.

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