Airflow adjusting structure and airflow adjusting method
By setting the eccentric first and second adjustment rings around the substrate, the adjustment ring is rotated to adjust the air gap, and the problem of film deposition inhomogeneity is solved, and the uniformity of film deposition and product yield is improved.
Patent Information
- Application Number
- CN202410166628.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-05
- Publication Date
- 2025-08-05
AI Technical Summary
The prior art cannot adjust the airflow simply and quickly, resulting in unevenness of film deposition on the substrate.
An airflow adjustment structure is designed, including a first and second adjustment ring surrounding the substrate, both of which are arranged eccentrically inside and outside, and the air gap is adjusted by rotating the adjustment ring to improve airflow uniformity, and a adjustment ring made of a dielectric material to focus radio frequency energy and reduce back deposition of the substrate.
The uniformity of film deposition on the substrate is improved, and the heat distribution unevenness caused by the eccentricity of the heating tray is avoided, and the film quality and product yield are improved.
Smart Images
Figure CN120425319A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of semiconductor manufacturing equipment, and in particular to an airflow regulating structure and an airflow regulating 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. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 Shown is a schematic diagram of the airflow regulating structure of the present invention;
[0026] Figure 2 A schematic diagram showing an adjustment ring of the airflow adjustment structure of the present invention;
[0027] Figure 3A and Figure 3B Schematic diagram showing the airflow regulation structure of the present invention before and after circumferential airflow regulation;
[0028] Figure 4A and Figure 4B A cross-sectional view showing some components of the air flow regulating structure of the present invention;
[0029] Figure 5 Shown is a schematic diagram of the bottom of the first adjustment ring in the airflow adjustment structure of the present invention;
[0030] Figure 6A and Figure 6B Shown is a schematic diagram of the airflow regulation structure of the present invention before and after radial airflow regulation;
[0031] Figure 7 Another schematic diagram showing the airflow regulation of the airflow regulation structure of the present invention. DETAILED DESCRIPTION
[0032] 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.
[0033] 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.
[0034] like Figure 1 As shown, this embodiment provides an airflow regulating structure 3 for a thin film deposition device, which includes: a processing chamber 1 for performing thin film deposition; a heating tray 2 for carrying and heating a substrate w. Figure 1 and Figure 2 , the airflow adjustment structure 3 includes a first adjustment ring 31 arranged around the substrate w and a second adjustment ring 32 arranged around the first adjustment ring 31. There can be a small gap between the first adjustment ring 31 and the substrate w, and the gap ranges from 0.5 to 1 mm, so as to facilitate the placement of the substrate w, while avoiding the gap being too large to cause the gas to flow to the back of the substrate w. Usually a circular ring includes an inner circle and an outer circle, and the center of the inner circle and the outer circle are the same. However, the inner circle and the outer circle of the first adjustment ring 31 and the second adjustment ring 32 of the present application are both eccentrically set, and the eccentric setting means that the center of the inner circle and the outer circle do not coincide. And the distance between the center of the inner circle and the center of the outer circle of the two adjustment rings is L1, that is, the distance between the inner circle and the outer circle of the first adjustment ring 31 is equal to the distance between the inner circle and the outer circle of the second adjustment ring 32. Among them, 0<L1<20mm. Preferably, L1 is 2mm.
[0035] 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.
[0036] When the air flow does not need to be adjusted, or in the initial state (ie before film deposition), the inner center of the first adjustment ring 31 coincides with the outer center of the second adjustment ring 32. Figure 2 As shown, at this time, the first adjustment ring 31 and the second adjustment ring 32 just form a concentric large ring, and the outer circle center and the inner circle 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.
[0037] When the thin film deposited on substrate w is uneven, airflow adjustment is required. Rotating the first adjustment ring 31 and / or the second adjustment ring 32 can adjust the air gap between the inner wall of the processing chamber 1 and the second adjustment ring 32, 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 air gap adjustment range is large, the relative positions of the first adjustment ring 31 and the second adjustment ring 32 can be adjusted so that the wider portions 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 simultaneously rotating the second adjustment ring 32, 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. Then, the second adjustment ring 32 can be rotated to further reduce the air gap between the second adjustment ring 32 and the inner wall of the processing chamber 1. Figure 3A and Figure 3B Schematic diagram of the front and back of the circumferential airflow adjustment. Figure 3A In the initial state, the first adjustment ring 31 and the second adjustment ring 32 form a concentric large ring. The air gap 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 in the entire circumferential direction. L0 is the radius difference between the outer circles of the processing chamber 1 and the second adjustment ring 32. After the second adjustment ring 32 is rotated 180° counterclockwise, as shown in FIG. Figure 3B As shown, 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 is thicker in the 9 o'clock area on the substrate w, 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 in this area, thereby reducing circumferential airflow and improving the uniformity of thin film deposition.
[0038] like Figure 1 As shown, the first adjustment ring 31 and the substrate w are supported above the heating tray 2 by the 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 sapphire ejector pin fixed in the opening at the top of the heating tray 2. Figure 4A and Figure 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. Figure 4A and Figure 4B Several shapes of shelf portions 311 are shown. Figure 4AIn the embodiment, the shelf portion 311 of the first adjustment ring 31 is a bevel, and correspondingly, the inner edge of the second adjustment ring 32 is provided with bevels that match each other. Figure 4B In the embodiment, the shelf portion 311 of the first adjustment ring 31 is a step, and the second adjustment ring 32 is provided with steps that match each other.
[0039] like Figure 5 As shown, the bottom of the first adjustment ring 31 is also provided with a plurality of positioning holes 312 evenly distributed along the circumference for receiving the top end of the support member 33. Preferably, there are six positioning holes 312, with adjacent positioning holes 312 spaced 60° apart. As the first adjustment ring 31 rotates, it rises away from the support member 33 and then descends after rotation, so that the top end of the support member 33 remains within the positioning holes 312. Therefore, the rotation angle of the first adjustment ring 31 is a multiple of 60°. The second adjustment ring 32 can rotate freely relative to the first adjustment ring 31.
[0040] In some embodiments, the height of the support member 33 below the first adjustment ring 31 may be changed to adjust the radial airflow. Figure 6A and Figure 6B This is a schematic diagram of adjusting the radial airflow before and after, and the arrows in the figure show the direction of the radial airflow. Figure 6A In the embodiment, the first adjustment ring 31, the second adjustment ring 32 and the substrate w are at the same height. Figure 6B In the comparison, the Figure 6A A higher support member 33 is provided to adjust the air gap between the first and second adjustment rings 31, 32, and the heating tray 2, so that the first and second adjustment rings 31, 32 are higher than the substrate w, changing the direction of the radial airflow and thereby adjusting the film thickness at the edge of the substrate w. This embodiment is suitable for adjusting the radial film thickness on the substrate w. For example, if the film around the edge of the substrate w is thicker, a higher support member 33 can be used to increase the air gap between the first and second adjustment rings 31, 32, and the heating tray 2, thereby reducing the radial airflow on the surface of the substrate w and improving the uniformity of thin film deposition.
[0041] In some embodiments, due to processing tolerances and other reasons, the heating tray 2 is not located in the center of the processing chamber. Figure 7As shown, 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. Therefore, the positions of the first adjustment ring 31 and the second adjustment ring 32 can be set before thin film deposition to compensate for the unevenness 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 adjustment ring 32 and the inner wall of the processing chamber 1 corresponding to the position of the minimum air gap d1 is set to S3, and the air gap between the second adjustment ring 32 and the inner wall of the processing chamber 1 corresponding to the position of the maximum air gap d2 is set to S4. The positions of the first adjustment ring 31 and the second adjustment ring 32 are adjusted so that S3 > S4. By increasing the air gap between the second adjustment 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 thin film deposition.
[0042] 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.
[0043] 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.