Airflow regulating structure and airflow regulating method

Abstract

An airflow regulating structure (3), comprising: a first regulating ring (31) arranged around a substrate (w) and a second regulating ring (32) arranged around the first regulating ring (31), wherein the outer circle of the first regulating ring (31) coincides with the inner circle of the second regulating ring (32), the inner circles and the outer circles of the first regulating ring (31) and the second regulating ring (32) are both eccentrically arranged, and the distance between the center of the inner circle and the center of the outer circle of the first regulating ring (31) is equal to the distance between the center of the inner circle and the center of the outer circle of the second regulating ring (32). Two regulating rings with eccentrically arranged inner circles and outer circles are provided around the substrate (w); thus, on the basis of the non-uniformity of a thin film at the edge of the substrate (w), the relative positions of the two regulating rings can be adjusted to adjust an air gap between an inner wall of a process chamber and the regulating rings, so as to regulate the airflow in a circumferential direction, thereby improving the uniformity of thin film deposition on the substrate (w).

Description

Airflow regulating structure and airflow regulating method Technical Field

[0001] The present application relates to the field of semiconductor manufacturing equipment, and in particular to an airflow regulation structure and an airflow regulation method. Background Art

[0002] In chemical vapor deposition (CVD) equipment, various dielectric thin films are deposited on substrate surfaces. Film thickness uniformity is a key process parameter, directly impacting film properties and product yield. Improving the uniformity of thin film deposition on substrates is crucial to meet the semiconductor industry's ongoing pursuit of high quality, high efficiency, low cost, and adaptability to large-scale substrates.

[0003] During the thin film deposition process, airflow uniformity has a significant impact on the uniformity of thin film deposition on the substrate. For example, in the following application scenarios, airflow adjustment is required to improve the uniformity of film thickness:

[0004] 1. Due to machining tolerances and other reasons, the heating tray is not located in the center of the processing chamber, resulting in uneven distribution of airflow in the circumferential direction, which affects the film thickness at the edge of the substrate;

[0005] 2. Due to the uncontrollable factors of airflow, the film thickness at the edge of the substrate is uneven, and it is necessary to adjust the airflow to adjust the film thickness at the edge of the substrate.

[0006] Therefore, it is crucial to design a structure that can adjust the airflow simply and quickly. Summary of the Invention

[0007] The object of the present invention is to provide an airflow regulating structure for solving the problem in the prior art that the airflow cannot be regulated simply and quickly.

[0008] To achieve the above-mentioned purpose and other related purposes, the present invention provides an airflow regulation structure for a thin film deposition device, wherein the thin film deposition device includes a processing chamber and a heating tray, and the airflow regulation structure includes: a first adjustment ring arranged around a substrate and a second adjustment ring arranged around the first adjustment ring, the outer circle of the first adjustment ring coincides with the inner circle of the second adjustment ring, the inner circle and outer circle of the first adjustment ring and the second adjustment ring are both eccentrically arranged, and the distance between the center of the inner circle and the center of the outer circle of the first adjustment ring and the second adjustment ring is equal.

[0009] Preferably, the distance L1 between the center of the inner circle and the center of the outer circle has a value range of: 0<L1<20mm.

[0010] Preferably, the distance L1 between the center of the inner circle and the center of the outer circle is 2 mm.

[0011] Preferably, it also includes a support member, which is arranged in the opening on the top of the heating tray, for supporting the first adjustment ring above the heating tray; the outer edge of the first adjustment ring is provided with a shelf portion formed downward from the upper surface, and the shelf portion is used to support the second adjustment ring.

[0012] Preferably, the shelf portion is a bevel or a step.

[0013] Preferably, the bottom of the first adjustment ring is provided with a plurality of positioning holes evenly distributed along the circumference for placing the top end of the support member.

[0014] Preferably, the first adjustment ring and the second adjustment ring are both made of dielectric material.

[0015] The present invention also provides an airflow regulation method, which adopts the above-mentioned airflow regulation structure and includes the following steps:

[0016] After rotating the first adjustment ring and the second adjustment ring until the outer center of the first adjustment ring overlaps with the inner center of the second adjustment ring, thin film deposition is performed on the substrate;

[0017] When the thin film deposition on the substrate is uneven, the second adjustment ring is rotated to reduce the air gap between the second adjustment ring and the inner wall of the processing chamber corresponding to the area where the film is thicker.

[0018] Preferably, before rotating the second adjustment ring, the first adjustment ring is rotated to drive the second adjustment ring to rotate, so that the air gap between the first adjustment ring and the inner wall of the processing chamber corresponding to the area where the film is thicker is reduced.

[0019] Preferably, the rotation angle of the first adjustment ring is a multiple of 360° / N, where N is the number of positioning holes uniformly distributed along the circumference of the bottom of the first adjustment ring.

[0020] The present invention also provides an airflow regulation method, which adopts the above-mentioned airflow regulation structure and includes the following steps:

[0021] Measure the concentricity between the heating plate and the processing chamber before thin film deposition on the substrate;

[0022] When the heating tray and the processing chamber are not concentric, the position of the first adjustment ring and / or the second adjustment ring is adjusted so that the air gap between the second adjustment ring corresponding to the position where the air gap between the heating tray and the processing chamber is the largest and the inner wall of the processing chamber is reduced.

[0023] The present invention also provides an airflow adjustment method using the above-mentioned airflow adjustment structure, comprising: when the thin film deposition on the substrate is uneven, adjusting the height of the support member to adjust the air gap between the first adjustment ring and the heating tray.

[0024] As described above, the present invention provides an airflow regulation structure having the following beneficial effects: two eccentrically arranged adjustment rings with an inner circle and an outer circle are arranged around the substrate, and the relative positions of the two adjustment rings can be adjusted according to the unevenness of the film at the edge of the substrate to adjust the air gap between the inner wall of the processing chamber and the adjustment rings, so as to adjust the airflow in the circumferential direction, thereby improving the uniformity of thin film deposition on the substrate.

[0025] Summary of the Figures

[0026] The features and performance of the present application are further described by the following examples and drawings.

[0027] FIG1 is a schematic diagram of an airflow regulating structure according to the present invention;

[0028] FIG2 is a schematic diagram showing an adjustment ring of an airflow adjustment structure according to the present invention;

[0029] 3A and 3B are schematic diagrams showing the airflow regulation structure of the present invention before and after circumferential airflow regulation;

[0030] 4A and 4B are cross-sectional views showing some components of the airflow regulating structure of the present invention;

[0031] FIG5 is a schematic diagram showing the bottom of the first adjustment ring in the airflow adjustment structure of the present invention;

[0032] 6A and 6B are schematic diagrams showing the radial airflow before and after adjustment in the airflow adjustment structure of the present invention;

[0033] FIG. 7 shows another schematic diagram of the airflow regulating structure of the present invention.

[0034] Preferred embodiment of this application

[0035] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0036] It should be noted that the illustrations provided in this embodiment are merely schematic illustrations of the basic concept of the present invention. Although the illustrations only show components relevant to the present invention and are not drawn according to the number, shape, and size of components in actual implementation, the form, quantity, and proportion of each component in actual implementation may be varied arbitrarily, and the component layout may be more complex. Furthermore, parts with the same reference numerals in multiple figures represent identical or equivalent parts or components.

[0037] As shown in Figure 1, this embodiment provides an airflow regulation structure 3 for a thin film deposition apparatus. The thin film deposition apparatus includes a processing chamber 1 for performing thin film deposition and a heating tray 2 for supporting and heating a substrate w. Referring to Figures 1 and 2, the airflow regulation structure 3 includes a first adjustment ring 31 disposed around the substrate w and a second adjustment ring 32 disposed around the first adjustment ring 31. A slight gap, ranging from 0.5 to 1 mm, can exist between the first adjustment ring 31 and the substrate w to facilitate placement of the substrate w while preventing excessive clearance from causing gas to flow toward the back of the substrate w. Typically, a circular ring includes an inner circle and an outer circle, with the inner and outer circles sharing the same center. However, in this application, the inner and outer circles of the first and second adjustment rings 31 and 32 are both eccentrically arranged, meaning that the inner and outer centers do not coincide. Furthermore, the distance between the inner and outer centers of both adjustment rings is L1. This means that the distance between the inner and outer circles of the first adjustment ring 31 is equal to the distance between the inner and outer circles of the second adjustment ring 32. Wherein, 0<L1<20mm. Preferably, L1 is 2mm.

[0038] The rotation center of the first adjustment ring 31 coincides with the rotation center of the substrate w. The inner center of the first adjustment ring 31, the center of the substrate w, and the center of the heating tray 2 coincide with each other. This means the rotation center of the first adjustment ring 31 is the inner center of the first adjustment ring 31. Rotating the first adjustment ring 31 also rotates the second adjustment ring 32. When the second adjustment ring 32 rotates independently, its rotation center is the outer center of the first adjustment ring 31, meaning its rotation center is the inner center of the second adjustment ring 32.

[0039] When there is no need to adjust the airflow, or in the initial state (i.e., before thin film deposition), the inner center of the first adjustment ring 31 coincides with the outer center of the second adjustment ring 32, as shown in FIG2 . At this time, the first adjustment ring 31 and the second adjustment ring 32 just form a concentric large ring, and the outer center and inner center of the large ring coincide with the center of the substrate. Therefore, the air gap between the inner wall of the processing chamber 1 and the large ring is uniform and consistent, which can ensure the uniformity of thin film deposition on the substrate w.

[0040] When the thin film deposited on substrate w is uneven, the airflow needs to be adjusted. By rotating the first adjustment ring 31 and / or the second adjustment ring 32, the air gap between the inner wall of the processing chamber 1 and the second adjustment ring 32 can be adjusted, thereby adjusting the circumferential airflow to adjust the film thickness circumferentially on substrate w. For example, the air gap between the inner wall of the processing chamber 1 and the second adjustment ring 32 corresponding to the area where the film is thicker can be reduced by rotating the second adjustment ring 32. When the adjustment range of the air gap is large, the relative positions of the first adjustment ring 31 and the second adjustment ring 32 can be adjusted so that the wider parts of the first adjustment ring 31 and the second adjustment ring 32 are closer to the area where the film is thicker on substrate w. For example, the first adjustment ring 31 can be rotated first, while driving the second adjustment ring 32 to rotate at the same time, so that the air gap between the first adjustment ring 31 and the inner wall of the processing chamber 1 corresponding to the area where the film is thicker is reduced, and then the second adjustment ring 32 can be rotated to reduce the air gap between the second adjustment ring 32 and the inner wall of the processing chamber 1. Figures 3A and 3B are schematic diagrams before and after adjusting the circumferential airflow. Referring to Figure 3A , in the initial state, the first adjustment ring 31 and the second adjustment ring 32 form concentric large rings. The air gaps S0 and L0 between the inner wall of the processing chamber 1 and the second adjustment ring 32 are equal, and the distance from the inner wall of the processing chamber 1 to the second adjustment ring 32 is the same throughout the entire circumference. L0 is the difference in radius between the outer circles of the processing chamber 1 and the second adjustment ring 32. After rotating the second adjustment ring 32 counterclockwise by 180°, as shown in Figure 3B , the air gap between the inner wall of the processing chamber 1 and the second adjustment ring 32 changes, with the minimum air gap S1 being L0-L1 and the maximum air gap S2 being L0+L1. This embodiment is suitable for adjusting the film thickness in the circumferential direction on a substrate w. For example, if the film in the 9 o'clock area on the substrate w is too thick, the first adjustment ring 31 and / or the second adjustment ring 32 can be rotated to reduce the air gap between the inner wall of the processing chamber 1 and the second adjustment ring 32 corresponding to this area, thereby reducing the circumferential airflow and improving the uniformity of the film deposition.

[0041] As shown in Figure 1, the first adjustment ring 31 and the substrate w are both supported above the heating tray 2 by a support member 33. During the process, the contact between the substrate w and the heating tray 2 is point contact rather than surface contact, which avoids the problem of uneven heat distribution caused by processing tolerances and better ensures the uniformity of thin film deposition. Specifically, the support member 33 is a thimble made of sapphire, which is fixed in the opening at the top of the heating tray 2. Referring to Figures 4A and 4B, the outer edge of the first adjustment ring 31 is provided with a shelf portion 311 formed downward from the upper surface to support the second adjustment ring 32. Figures 4A and 4B show several shapes of the shelf portion 311. In Figure 4A, the shelf portion 311 of the first adjustment ring 31 is a bevel, and accordingly, the inner edge of the second adjustment ring 32 is provided with mutually matching bevels. In Figure 4B, the shelf portion 311 of the first adjustment ring 31 is a step, and the second adjustment ring 32 is provided with mutually matching steps.

[0042] As shown in FIG. 5, a plurality of positioning holes 312 evenly distributed along the circumference are further provided at the bottom of the first adjusting ring 31 for placing the top end of the support member 33. Preferably, the number of the positioning holes 312 is 6, and the interval between adjacent positioning holes 312 is 60°. When the first adjusting ring 31 rotates, the first adjusting ring 31 rises and leaves the support member 33, and then falls after the rotation is completed so that the top end of the support member 33 is still placed in the positioning hole 312. Therefore, the rotation angle of the first adjusting ring 31 is a multiple of 60°. The second adjusting ring 32 can rotate freely relative to the first adjusting ring 31.

[0043] In some embodiments, the height of the support member 33 below the first adjusting ring 31 can also be changed to adjust the radial air flow. FIGS. 6A and 6B are schematic diagrams before and after adjusting the radial air flow, and the arrows in the figures show the direction of the radial air flow. In FIG. 6A, the first adjusting ring 31, the second adjusting ring 32 and the substrate w are at the same height. In FIG. 6B, the support member 33 with a higher height than that in FIG. 6A is replaced to adjust the air gap between the first adjusting ring 31, the second adjusting ring 32 and the heating tray 2, so that the first adjusting ring 31 and the second adjusting ring 32 are higher than the substrate w, change the direction of the radial air flow, and further adjust the film thickness at the edge of the substrate w. This embodiment is applicable to adjusting the radial film thickness on the substrate w. For example, if the film on the edge of the substrate w is too thick, the support member 33 with a higher height can be used to increase the air gap between the first adjusting ring 31, the second adjusting ring 32 and the heating tray 2, so as to reduce the radial air flow on the surface of the substrate w, thereby improving the uniformity of film deposition.

[0044] In some embodiments, due to processing tolerances and other reasons, the heating tray 2 is not in the exact middle of the processing chamber. As shown in FIG. 7, the air gaps between the two sides of the heating tray 2 and the inner wall of the processing chamber 1 are d1 and d2 respectively, and d1 < d2. Then, the positions of the first adjusting ring 31 and the second adjusting ring 32 can be set before film deposition to compensate for the non-uniformity of the air gap between the heating tray 2 and the inner wall of the processing chamber 1. Specifically, the air gap between the second adjusting ring 32 corresponding to the position of the minimum air gap d1 and the inner wall of the processing chamber 1 is set as S3, and the air gap between the second adjusting ring 32 corresponding to the position of the maximum air gap d2 and the inner wall of the processing chamber 1 is set as S4. The positions of the first adjusting ring 31 and the second adjusting ring 32 are adjusted so that S3 > S4. By increasing the air gap between the second adjusting ring 32 and the inner wall of the processing chamber 1, the minimum air gap between the heating tray 2 and the inner wall of the processing chamber 1 is compensated, and the uniformity of the air flow is adjusted to improve the uniformity of film deposition.

[0045] The first adjustment ring 31 and the second adjustment ring 32 are both made of a dielectric material, including but not limited to quartz, alumina, and ceramic. When used in a plasma-enhanced chemical vapor deposition (PECVD) apparatus, the first adjustment ring 31 and the second adjustment ring 32 can also function as focusing rings. By introducing additional impedance, the first adjustment ring 31 and the second adjustment ring 32 focus the RF energy on the substrate w, preventing the gas from flowing to the back side of the substrate w and reducing deposition on the back side of the substrate w.

[0046] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. An airflow regulating structure for a thin film deposition device, wherein the thin film deposition device comprises a processing chamber and a heating tray, characterized in that: The airflow regulation structure includes: a first adjustment ring arranged around the substrate and a second adjustment ring arranged around the first adjustment ring, the outer circle of the first adjustment ring coincides with the inner circle of the second adjustment ring, the inner circle and outer circle of the first adjustment ring and the second adjustment ring are both eccentrically arranged, and the distance between the center of the inner circle and the center of the outer circle of the first adjustment ring and the second adjustment ring is equal.

2. The airflow regulating structure according to claim 1, characterized in that: The distance L1 between the center of the inner circle and the center of the outer circle has a value range of 0 < L1 < 20 mm.

3. The airflow regulating structure according to claim 2, characterized in that: The distance L1 between the center of the inner circle and the center of the outer circle is 2 mm.

4. The airflow regulating structure according to claim 1, characterized in that: It also includes a support member, which is arranged in the opening on the top of the heating tray and is used to support the first adjustment ring above the heating tray; the outer edge of the first adjustment ring is provided with a shelf portion formed downward from the upper surface, and the shelf portion is used to support the second adjustment ring.

5. The airflow regulating structure according to claim 4, characterized in that: The shelf portion is a bevel or a step.

6. The airflow regulating structure according to claim 4, characterized in that: The bottom of the first adjustment ring is provided with a plurality of positioning holes evenly distributed along the circumference for placing the top end of the support member.

7. The airflow regulating structure according to claim 1, characterized in that: The first adjustment ring and the second adjustment ring are both made of dielectric material.

8. An airflow regulating method, applied to the airflow regulating structure according to any one of claims 1 to 7, characterized in that: The following steps are involved: After rotating the first adjustment ring and the second adjustment ring until the outer center of the first adjustment ring overlaps with the inner center of the second adjustment ring, thin film deposition is performed on the substrate; When the thin film deposition on the substrate is uneven, the second adjustment ring is rotated to reduce the air gap between the second adjustment ring and the inner wall of the processing chamber corresponding to the area where the film is thicker.

9. The airflow adjustment method according to claim 8, characterized in that: Before rotating the second adjustment ring, the first adjustment ring is rotated to drive the second adjustment ring to rotate, so that the air gap between the first adjustment ring and the inner wall of the processing chamber corresponding to the area where the film is thicker is reduced.

10. The airflow adjustment method according to claim 9, characterized in that: The rotation angle of the first adjustment ring is a multiple of 360° / N, where N is the number of positioning holes uniformly distributed along the circumference of the bottom of the first adjustment ring.

11. An airflow regulating method, applied to the airflow regulating structure according to any one of claims 1 to 7, characterized in that: include: Measure the concentricity between the heating plate and the processing chamber before thin film deposition on the substrate; When the heating tray and the processing chamber are not concentric, the position of the first adjustment ring and / or the second adjustment ring is adjusted so that the air gap between the second adjustment ring corresponding to the position where the air gap between the heating tray and the processing chamber is the largest and the inner wall of the processing chamber is reduced.

12. An airflow regulating method, applied to the airflow regulating structure according to any one of claims 4 to 6, characterized in that: include: When the thin film deposition on the substrate is uneven, the height of the support member is adjusted to adjust the air gap between the first adjustment ring and the heating tray.

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