Wafer etching device
By setting up external heating elements and temperature sensor control systems in the wafer etching device, the problem of ineffective heating of the wafer edge is solved, the uniformity of the etching depth and key dimensions on the wafer surface is achieved, and the etching yield and quality are improved.
Patent Information
- Application Number
- CN202510847903.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-23
- Publication Date
- 2025-09-26
AI Technical Summary
The edge of the wafer cannot effectively receive the heat from the chuck, resulting in abnormal etching, affecting the uniformity of the etching depth and critical dimensions, and reducing the etching yield.
The first heating element is located outside the carrying surface to heat the edge of the wafer, and the second heating element is used to heat the chuck. The working state of the heating element is finely controlled by the temperature sensor and controller to keep the overall temperature of the wafer consistent. The third heating element is used to control the gas temperature in the etching chamber to ensure that the etching reaction is carried out at the appropriate temperature.
The uniformity of etching depth and critical dimensions on the wafer surface is achieved, etching anomalies are avoided, and the etching yield and etching quality at the edge of the wafer are improved.
Smart Images
Figure CN120709190A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a wafer etching device. Background Art
[0002] The wafer etching system applies a certain electrostatic voltage to the chuck's support surface, which holds the wafer in place. The chuck also has a built-in heater to control the wafer's temperature. Wafer temperature is closely related to the etching rate.
[0003] When the wafer is fixed on the chuck, the edge of the wafer will extend beyond the supporting surface of the chuck. Therefore, the heat of the chuck cannot be effectively transferred to the edge of the wafer, resulting in abnormal etching of the edge of the wafer. Summary of the Invention
[0004] The present application provides a wafer etching device. The wafer etching device includes an etching chamber and a chuck, a first heating element, and a second heating element located in the etching chamber;
[0005] The chuck includes a carrying surface for carrying a wafer; the first heating element is located outside the carrying surface and spaced apart from the carrying surface, and is used to heat an edge portion of the wafer carried by the carrying surface that extends beyond the carrying surface; the second heating element is used to heat the chuck;
[0006] The height of one end of the first heating element away from the bottom wall of the etching chamber is greater than the height of the carrying surface.
[0007] In one embodiment, the wafer etching device further includes a first controller, and the first controller is used to control the first heating element to heat and stop heating.
[0008] In one embodiment, the wafer etching device further includes a first temperature sensor and a second temperature sensor; the first temperature sensor is used to detect the temperature of a portion of the wafer extending beyond the carrying surface when the wafer is placed on the carrying surface, and the second temperature sensor is used to detect the temperature of a portion of the wafer in contact with the carrying surface when the wafer is placed on the carrying surface;
[0009] The first temperature sensor and the second temperature sensor are electrically connected to the first controller respectively. The first controller controls the first heating element according to temperature values detected by the first temperature sensor and the second temperature sensor.
[0010] In one embodiment, the first heating element is disposed inside or on an inner surface of a sidewall of the etching chamber.
[0011] In one embodiment, the first heating element includes a plurality of heating segments, and the plurality of heating segments are arranged at intervals along the circumferential direction.
[0012] In one embodiment, the central axis of the side wall and the center of the bearing surface are on the same straight line.
[0013] In one embodiment, the side wall of the etching chamber is provided with a through hole, the height of the through hole is greater than the height of the carrying surface, and is less than or equal to the height of the end of the first heating element away from the bottom wall of the etching chamber; the wafer etching device also includes a fan located on the outside of the side wall, and the fan is used to blow the heat generated by the first heating element to the edge portion of the wafer beyond the carrying surface through the through hole.
[0014] In one embodiment, the wafer etching apparatus further includes a third heating element; the third heating element is used to heat the gas in the etching chamber; the third heating element includes a first sub-heating element, the first sub-heating element is located on a side of the first heating element away from the bottom wall of the etching chamber; and / or the third heating element includes a second sub-heating element, the second sub-heating element is located on a side of the first heating element facing the bottom wall of the etching chamber;
[0015] The wafer etching device further includes a second controller, which is used to control the third heating element to heat and stop heating.
[0016] In one embodiment, the wafer etching device also includes a third temperature sensor, which is used to detect the ambient temperature in the etching chamber; the second controller is electrically connected to the third temperature sensor, and controls the third heating element according to the temperature detected by the third temperature sensor.
[0017] In one embodiment, a height difference between an end of the first heating element away from the bottom wall of the etching chamber and an end of the first heating element facing the bottom wall of the etching chamber ranges from 10 cm to 30 cm.
[0018] The wafer etching device provided in the embodiment of the present application can keep the temperature of the part of the wafer in contact with the carrying surface consistent with the temperature of the part of the wafer that extends beyond the carrying surface, so that the etching reaction can proceed at basically the same rate on the entire wafer surface, which is beneficial to ensure the uniformity of the etching depth and critical dimensions, avoid etching abnormalities at the edge of the wafer due to temperature differences, and improve the etching yield of the edge of the wafer.
[0019] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.
[0021] Figure 1 A schematic diagram of the positional relationship between a wafer and a chuck in the related art;
[0022] Figure 2 Schematic diagram of the relationship between wafer etching depth and critical dimension and distance from the wafer center in related art;
[0023] Figure 3 A schematic structural diagram of a wafer etching device provided in one embodiment of the present application;
[0024] Figure 4 A schematic diagram of a portion of the structure of a wafer etching device provided in one embodiment of the present application. DETAILED DESCRIPTION
[0025] Here, the technical solutions in the embodiments (or "implementations") of the present application will be clearly and completely described in conjunction with the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.
[0026] If there are terms involving directional indications or positional relationships in the embodiments of this application (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationship, movement, etc. between the components in a specific posture (as shown in the accompanying drawings); if the specific posture changes, the directional indication or positional relationship will also change accordingly. In addition, the terms "first" and "second" in the embodiments of this application are only used for descriptive convenience and should not be understood as indicating or implying relative importance.
[0027] The wafer etching device in the related art includes a chuck, which includes a carrying surface for fixing the wafer, such as Figure 1 As shown, when the size of the wafer 200 ′ is larger than the size of the carrying surface 101 ′ of the chuck, after the wafer 200 ′ is fixed to the carrying surface 101 ′, the edge of the wafer 200 ′ will extend beyond the carrying surface 101 ′ of the chuck.
[0028] When the chuck is used to heat the wafer 200', the portion of the wafer 200' that extends beyond the support surface is not in direct contact with the chuck, and the temperature of the chuck cannot be effectively transferred to the edge of the wafer 200', resulting in abnormal etching of the edge of the wafer. Figure 2As shown, in the wafer etching device of the related art, the etching depth and critical dimension uniformity of the area where the wafer 200' is in direct contact with the carrier surface 101' (that is, the portion of the wafer located in the A' area) are good, while the etching depth and critical dimension of the edge area of the wafer exceeding the carrier surface (that is, the portion of the wafer located in the B' area) are smaller, which ultimately has an adverse effect on the performance of the chip.
[0029] The wafer etching device of the embodiment of the present application is described in detail below with reference to the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can complement or be combined with each other.
[0030] The embodiment of the present application provides a wafer etching device, such as Figure 3 As shown, the wafer etching apparatus 100 includes an etching chamber and a chuck 10 , a first heating element 41 , and a second heating element 42 located in the etching chamber.
[0031] The chuck 10 includes a carrying surface 101 for carrying a wafer 200. The etching chamber includes sidewalls 20 and a bottom wall 30. The first heating element 41 is located outside the carrying surface 101 and spaced apart from the carrying surface 101. It is used to heat the edge portion of the wafer carried by the carrying surface 101 that extends beyond the carrying surface 101. The second heating element 42 is used to heat the chuck 10. The height of the first heating element 41 at the end away from the bottom wall 30 is greater than the height of the carrying surface 101.
[0032] like Figure 3 As shown, after the wafer 200 is fixed to the carrying surface 101, the portion of the wafer 200 located in area A is in direct contact with the carrying surface 101. The carrying surface 101 can be heated by the second heating element 42, and the carrying surface 101 transfers the heat to the portion of the wafer 200 located in area A. Since the height of the end of the first heating element 41 away from the bottom wall 30 is greater than the height of the carrying surface 101, and the edge portion of the wafer 200 that extends beyond the carrying surface 101 (that is, the portion located in area B) is close to the first heating element 41, the heat of the first heating element 41 can be transferred to the edge portion of the wafer 200 that extends beyond the carrying surface 101, thereby helping to keep the temperature of the portion of the wafer 200 located in area B consistent with the temperature of the portion of the wafer 200 located in area A.
[0033] During the wafer etching process, wafer temperature affects the etch rate. When the temperature of the wafer 200 located in area A and area B is consistent, the etching reaction can proceed at a substantially uniform rate across the entire surface of the wafer 200. This helps ensure uniformity in etch depth and critical dimensions, avoids etching anomalies at the edge of the wafer 200 due to temperature differences, and improves the etching yield at the edge of the wafer 200.
[0034] In one embodiment, Figure 3 As shown, the wafer etching apparatus further includes a third heating element 43, which is used to heat the gas within the etching chamber. During plasma etching of wafer 200, if the ambient temperature within the etching chamber is too low, plasma generation may be inhibited, resulting in a decrease in active species in the etching reaction and a reduction in the etching rate. The third heating element 43 can be used to control the temperature within the etching chamber, ensuring that the etching reaction proceeds at an appropriate temperature, which is beneficial for improving wafer etching quality.
[0035] In one embodiment, the third heating element 43 includes a first sub-heating element 431 , and the first sub-heating element 431 is located on a side of the first heating element 41 away from the bottom wall 30 of the etching chamber.
[0036] In one embodiment, the third heating element 43 includes a second sub-heating element 432 , and the second sub-heating element 432 is located on a side of the first heating element 41 facing the bottom wall 30 of the etching chamber.
[0037] In one embodiment, Figure 3 As shown, the wafer etching apparatus 100 further includes a first controller 51, which is used to control the first heating element 41 to start and stop heating. The first controller 51 can automatically adjust the working state of the first heating element 41 without manual operation.
[0038] In one embodiment, Figure 3 As shown, the wafer etching apparatus 100 further includes a second controller 52, which is used to control the third heating element 43 to start and stop heating. The second controller 52 can automatically adjust the working state of the third heating element 43 without manual operation.
[0039] In one embodiment, the wafer etching apparatus 100 further includes a third controller for controlling the second heating element 42 to heat or stop heating the chuck 10. The third controller can automatically adjust the working state of the second heating element 42 without manual operation.
[0040] In one embodiment, Figure 3As shown, the wafer etching apparatus 100 further includes a first temperature sensor 61 and a second temperature sensor 62. The first temperature sensor 61 is used to detect the temperature of the portion of the wafer 200 extending beyond the carrying surface 101 when the wafer 200 is placed on the carrying surface 101. The second temperature sensor 62 is used to detect the temperature of the portion of the wafer 200 in contact with the carrying surface 101 when the wafer 200 is placed on the carrying surface 101. The first temperature sensor 61 and the second temperature sensor 62 are respectively electrically connected to the first controller 51. The first controller 51 controls the first heating element 41 based on the temperature values detected by the first temperature sensor 61 and the second temperature sensor 62.
[0041] The first temperature sensor 61 can detect the temperature of the portion of the wafer located in area A in real time, and the second temperature sensor 62 can detect the temperature of the portion of the wafer located in area B in real time. The first controller 51 can finely regulate the temperature of the first heating element wafer based on the temperature difference detected by the two, which is conducive to keeping the temperature of the entire wafer consistent and improving the accuracy of wafer temperature control. Specifically, when the temperature detected by the first temperature sensor 61 is lower than the temperature detected by the second temperature sensor 62, the first controller 51 can increase the current passing through the first heating element 41 to increase its heating efficiency, thereby reducing the temperature difference between the portion of the wafer located in area A and the portion located in area B; when the temperature detected by the first temperature sensor 61 is higher than the temperature detected by the second temperature sensor 62, the first controller 51 can control the first heating element 41 to stop heating.
[0042] In one embodiment, the wafer etching apparatus 100 further includes a third temperature sensor, which is used to detect the temperature of the etching chamber, and the second controller 52 is used to control the working state of the third heating element according to the ambient temperature detected by the third temperature sensor. In this way, the second controller 52 controls the third heating element 43 according to the ambient temperature of the etching chamber, so that the temperature in the etching chamber is basically maintained at a desired temperature. Specifically, when the third temperature sensor detects that the temperature of the etching chamber is lower than the desired temperature, the second controller 52 controls the third heating element 43 to heat the side wall 20 to increase the temperature of the etching chamber; when the third temperature sensor detects that the temperature of the etching chamber reaches the desired temperature or is higher than the desired temperature, the second controller 52 controls the third heating element 43 to stop heating the side wall 20.
[0043] In one embodiment, the first heating element 41 is disposed within or on the inner surface of the sidewall 20. When the first heating element 41 is disposed within the sidewall 20, the first heating element 41 transfers heat to the sidewall of the etching chamber, which in turn transfers the heat to the edge of the wafer. When the first heating element 41 is disposed on the inner surface of the sidewall 20, the heat generated by the first heating element 41 does not need to be conducted through the sidewall of the etching chamber, thereby improving heat transfer efficiency.
[0044] In one embodiment, the first heating element 41 includes multiple heating segments spaced apart along the circumference. This arrangement ensures uniform temperature distribution across the portion of the wafer 200 extending beyond the support surface, thereby improving etching quality. In some embodiments, the first heating element includes multiple connecting segments, which are used to connect adjacent heating segments.
[0045] In one embodiment, Figure 3 and Figure 4 As shown, the side wall 20 is annular and is geometrically adapted to the wafer 200 .
[0046] In one embodiment, Figure 3 and Figure 4 As shown, the central axis of the sidewall 20 is collinear with the center of the support surface. When the wafer 200 is placed on the support surface 101, the center of the wafer 200 substantially coincides with the center of the support surface 101. Since the central axis of the sidewall 20 and the center of the support surface are collinear, the center of the wafer 200 substantially coincides with the central axis of the sidewall. With this arrangement, the distances from each heating segment of each first heating element 41 to the edge of the portion of the wafer located in region B are substantially equal, resulting in a smaller difference in the amount of heat received by the edge of the wafer 200, which helps further improve the overall temperature consistency of the wafer 200.
[0047] In one embodiment, the first heating element 41 , the second heating element 42 and the third heating element 43 may be resistance wires.
[0048] In one embodiment, Figure 3 As shown, the height difference between the end of the first heating element 41 away from the bottom wall 30 and the end facing the bottom wall 30 ranges from 10 cm to 30 cm. This configuration can effectively control the temperature of the edge of the wafer 200 to maintain a consistent temperature of the entire wafer 200, while also reducing the temperature impact of the first heating element 41 on other areas within the etching chamber.
[0049] In one embodiment, the height of the end of the first heating element 41 facing the bottom wall 30 is less than the height of the support surface 101. After the wafer 200 is placed on the support surface 101, the surface of the wafer is located between the two ends of the first heating element 41. This helps to more concentrate the heat generated by the first heating element 41 and efficiently transfer it to the edge area of the wafer 200.
[0050] In one embodiment, Figure 3 As shown, the side wall is provided with a through hole 213, the height of the through hole 213 is greater than the height of the carrying surface 101, and is less than or equal to the height of the end of the first heating element 41 away from the bottom wall 30. The wafer etching device 100 also includes a fan located on the outside of the side wall 20, and the fan is used to blow the heat generated by the first heating element 41 to the edge portion of the wafer 200 beyond the carrying surface 101 through the through hole 213. When the fan located on the outside of the side wall 20 is turned on, an airflow can be formed, and the airflow passes through the through hole 213 and transports the heat generated by the first heating element 41 to the portion of the wafer located in area B, thereby helping to improve the heat transfer efficiency. Specifically, the number of through holes 213 can be multiple, and when the side wall 20 is annular, the multiple through holes 213 are evenly spaced along the circumference of the side wall.
[0051] In one embodiment, Figure 3 As shown, the wafer etching apparatus further includes an edge ring 70 disposed around the chuck 10. The edge ring 70 includes an annular step 71, the upper surface of which is higher than the height of the support surface 101. When the wafer 200 is secured to the support surface 101, the edge of the wafer 200 abuts against the side of the step 71. The edge ring 70 can regulate the electric field and reduce physical damage to the edge of the wafer 200 during the etching process.
[0052] In one embodiment, Figure 3 As shown, the height of the end of the first heating element 41 away from the bottom wall 30 is greater than the height of the upper surface of the step portion 71 of the edge ring 70. This helps to fully transfer the heat generated by the first heating element 41 to the portion of the wafer 200 beyond the carrying surface 101.
[0053] In one embodiment, Figure 3 As shown, the second temperature sensor 62 is disposed on the carrying surface 101 . The first temperature sensor 61 is disposed on the upper surface of the edge ring 70 . When the wafer 200 is fixed to the carrying surface 101 , the orthographic projection of the portion of the wafer 200 extending beyond the carrying surface 101 on the edge ring 70 covers the first temperature sensor 61 .
[0054] In one embodiment, the chuck 10 can adsorb the wafer 200 by static electricity.
[0055] It should be noted that the technical solutions or technical features described in the above embodiments can be combined or supplemented with each other without conflict. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the accompanying drawings; all modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application shall be included in the scope of protection of this application.
Claims
1. A wafer etching device, characterized in that: The wafer etching device includes an etching chamber and a chuck, a first heating element and a second heating element located in the etching chamber; The chuck includes a carrying surface for carrying a wafer; the first heating element is located outside the carrying surface and spaced apart from the carrying surface, and is used to heat an edge portion of the wafer carried by the carrying surface that extends beyond the carrying surface; the second heating element is used to heat the chuck; The height of one end of the first heating element away from the bottom wall of the etching chamber is greater than the height of the carrying surface.
2. The wafer etching device according to claim 1, wherein: The wafer etching device further includes a first controller, which is used to control the first heating element to heat and stop heating.
3. The wafer etching device according to claim 2, characterized in that: The wafer etching device further includes a first temperature sensor and a second temperature sensor; the first temperature sensor is used to detect the temperature of a portion of the wafer extending beyond the carrying surface when the wafer is placed on the carrying surface, and the second temperature sensor is used to detect the temperature of a portion of the wafer in contact with the carrying surface when the wafer is placed on the carrying surface; The first temperature sensor and the second temperature sensor are electrically connected to the first controller respectively. The first controller controls the first heating element according to temperature values detected by the first temperature sensor and the second temperature sensor.
4. The wafer etching device according to claim 1, wherein: The first heating element is disposed inside or on an inner surface of a sidewall of the etching chamber.
5. The wafer etching device according to claim 4, characterized in that: The first heating element includes a plurality of heating segments, and the plurality of heating segments are arranged at intervals along the circumferential direction.
6. The wafer etching device according to claim 5, characterized in that: The central axis of the side wall and the center of the bearing surface are on the same straight line.
7. The wafer etching device according to claim 1, wherein: The side wall of the etching chamber is provided with a through hole, the height of the through hole is greater than the height of the carrying surface, and is less than or equal to the height of the end of the first heating element away from the bottom wall of the etching chamber; the wafer etching device also includes a fan located on the outside of the side wall, and the fan is used to blow the heat generated by the first heating element to the edge portion of the wafer beyond the carrying surface through the through hole.
8. The wafer etching device according to claim 1, wherein: The wafer etching apparatus further includes a third heating element; the third heating element is used to heat the gas in the etching chamber; the third heating element includes a first sub-heating element, the first sub-heating element is located on a side of the first heating element away from the bottom wall of the etching chamber; and / or the third heating element includes a second sub-heating element, the second sub-heating element is located on a side of the first heating element facing the bottom wall of the etching chamber; The wafer etching device further includes a second controller, which is used to control the third heating element to heat and stop heating.
9. The wafer etching device according to claim 8, characterized in that: The wafer etching device also includes a third temperature sensor, which is used to detect the ambient temperature in the etching chamber; the second controller is electrically connected to the third temperature sensor and controls the third heating element according to the temperature detected by the third temperature sensor.
10. The wafer etching device according to claim 1, wherein: A height difference between an end of the first heating element away from the bottom wall of the etching chamber and an end of the first heating element facing the bottom wall of the etching chamber ranges from 10 cm to 30 cm.