A power regulation device for wafer deposition uniformity and a PECVD apparatus

Abstract

The utility model discloses a kind of power regulating device and PECVD equipment making wafer deposition uniform, it is related to the technical field of PECVD equipment on chip manufacturing production line;Its device includes several impedance adjusting branch;Each impedance adjusting branch includes series connection inductance element and ceramic capacitor array;The ceramic capacitor array includes the multiple ceramic capacitors of parallel connection, and each ceramic capacitor front end is configured with independent electronic switch.Each impedance adjusting branch is parallelly connected with corresponding branch load to form radio frequency adjusting branch, and signal passage is formed by branch filter series connection, and the power distribution of single wafer station can be independently controlled.This device uses parallel topology structure, is arranged between radio frequency source RF and ground GND, ensure that at least one electronic switch keeps on state.This application is significantly superior to conventional scheme in cost, reliability, adjusting speed and volume etc.

Description

Technical Field

[0001] This utility model relates to the technical field of PECVD equipment on chip manufacturing production lines, specifically to a power adjustment device and PECVD equipment for homogenizing wafer deposition. Background Technology

[0002] In PECVD equipment on chip production lines, to increase equipment capacity, multiple stations are typically set up within a single machine to process wafers in parallel. However, this multi-station design introduces the problem of process uniformity between stations. Process uniformity is mainly affected by temperature distribution, airflow distribution, and plasma distribution on the stations and wafers. Temperature and airflow distribution can be improved by optimizing the mechanical structure, while plasma distribution is influenced by more complex factors. Adjusting the mechanical structure alone is insufficient to achieve ideal uniformity; it must be combined with electrical control methods such as RF power regulation to effectively improve uniformity.

[0003] Existing power regulation devices employ a traditional approach based on a variable vacuum capacitor and a motor, where the capacitor value is adjusted by driving a rotating component of the variable vacuum capacitor via a motor. This traditional approach has significant drawbacks: 1. In terms of cost, its core component, the variable vacuum capacitor, significantly increases the equipment cost; 2. In terms of reliability, relying on motor-driven mechanical moving parts to adjust the capacitor value not only has serious mechanical wear problems, but also the mean time between failures (MTBF) of high-end motors is only about 100,000 hours, resulting in poor reliability. 3. Regarding speed adjustment, due to the limitation of motor speed, the response time of capacitor adjustment is as long as seconds, which makes it difficult to meet the needs of rapid adjustment; 4. In terms of size, the combination of motor and variable vacuum capacitor has the structural defect of being bulky and cannot be integrated on a single PCB circuit board. Utility Model Content

[0004] The purpose of this invention is to provide a power adjustment device and PECVD equipment that can homogenize wafer deposition. It controls the connection and cut-out of ceramic capacitors through electronic switches to achieve uniform control of the film thickness between wafers.

[0005] To achieve the above objectives, the technical solution of this application is as follows: a power regulation device for uniform wafer deposition, comprising several impedance regulation branches; each impedance regulation branch includes an inductor and a ceramic capacitor array connected in series; the ceramic capacitor array includes multiple ceramic capacitors connected in parallel, and each ceramic capacitor is equipped with an independent electronic switch at its front end.

[0006] In a preferred embodiment of this utility model, each impedance adjustment branch is connected in parallel with the corresponding branch load to form an RF adjustment branch.

[0007] In a preferred embodiment of this utility model, the input terminal of the radio frequency conditioning branch is sequentially connected to the corresponding branch filter to form a series signal path.

[0008] As a preferred embodiment of this utility model, each signal path controls the power distribution of a single wafer workstation, and the multiple signal paths are configured in a parallel topology.

[0009] In a preferred embodiment of this invention, each impedance adjustment branch has at least one electronic switch that is in the on state.

[0010] In a preferred embodiment of this invention, the electronic switch is located between the inductor and the corresponding ceramic capacitor.

[0011] In a preferred embodiment of this invention, the electronic switch is connected to the control system of the PECVD equipment.

[0012] In a preferred embodiment of this invention, the electronic switch is a MOSFET device, an IGBT, or a vacuum relay.

[0013] This invention also provides a PECVD device having the aforementioned power adjustment device for homogenizing wafer deposition.

[0014] As a preferred embodiment of the present invention, the PECVD equipment has two radio frequency sources, each equipped with a corresponding power adjustment device to homogenize wafer deposition.

[0015] By adopting the above technical solution, this utility model can achieve the following technical effects: 1. By adopting an electronic switch and ceramic capacitor array design, the cost is only one-tenth that of the traditional variable vacuum capacitor solution, resulting in a significant price reduction.

[0016] 2. Based on electronic switches such as MOSFET devices, mechanical moving parts are completely eliminated, and the mean time between failures (MTBF) can reach 1 billion hours, improving reliability by 10% compared to traditional solutions. 4 times.

[0017] 3. The electronic switch achieves a response time in the microsecond range, representing a performance improvement of up to 10% compared to the second-level adjustment speed of traditional mechanical solutions. 6 It can achieve instantaneous and precise adjustment.

[0018] 4. This device can be integrated onto a single PCB circuit board. Under the same area conditions, the thickness is only 1 / 3 to 1 / 5 of the traditional solution, which greatly saves installation space.

[0019] 5. Electronic switches avoid the wear and tear problems of traditional mechanical parts, basically achieving maintenance-free operation and significantly reducing operating costs. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 Here is a schematic diagram of the structure of several impedance adjustment branches; Figure 2 A schematic diagram of the power adjustment device for achieving uniform wafer deposition.

[0022] The numbers in the diagram are explained as follows: 1. Impedance adjustment branch; 11. Ceramic capacitor; 12. Electronic switch; 13. Inductor; 2. Branch load; 3. Branch filter. Detailed Implementation

[0023] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0024] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] Example 1 like Figure 1 As shown, this embodiment provides a power regulation device for homogenizing wafer deposition, including several impedance regulation branches; each impedance regulation branch includes an inductor and a ceramic capacitor array connected in series; the ceramic capacitor array includes multiple ceramic capacitors connected in parallel, and each ceramic capacitor is equipped with an independent electronic switch at its front end.

[0026] like Figure 2As shown, each impedance regulation branch is connected in parallel with its corresponding branch load to form an RF regulation branch, and a signal path is formed by connecting the branch filters in series, which can independently control the power distribution of a single wafer station. This device adopts a parallel topology structure, which is set between the RF source and ground (GND) to ensure that at least one electronic switch remains in the conducting state. The electronic switch is preferably set between the inductor and the capacitor and connected to the PECVD main control system (such as a PLC, industrial computer board, etc.).

[0027] In a preferred embodiment provided in this example, the ceramic capacitor array includes ceramic capacitors C1, C2, C3, ..., Cm, and corresponding electronic switches M1, M2, M3, ..., Mm, respectively. When electronic switch M1 is on and electronic switches M2, M3, ..., Mm are all off, the adjustable impedance is jωL+1 / jωC1. When electronic switches M1 and M2 are on and electronic switches M3, ..., Mm are all off, the adjustable impedance is jωL+1 / jω(C1+C2), and so on. When electronic switches M1, M2, M3, ..., Mm are all on, the adjustable impedance is jωL+1 / jω As the impedance Z is adjusted d1 Z d2 Z d3 ... Z dn Changes in branch load Z l1 Z l2 Z l3 ... Z ln The applied radio frequency power will change.

[0028] In PECVD equipment, electronic switches M1, M2, M3... Mm are usually MOSFETs. Depending on the voltage rating and power, they can also be replaced with IGBTs, vacuum relays, etc.

[0029] This embodiment uses a parallel array of ceramic capacitors, and electronic switches are used to switch the capacitors in and out, thereby changing the branch impedance and adjusting the distribution of RF power in different branches. The capacitor values ​​in the parallel array are C1, 2C1, 4C1, 8C1...2 m The multiple distribution of C1, combined with electronic switches, can achieve a total capacitance value of C1, 2C1, 3C1, 4C1... (2) m+1 -1) The smooth distribution of C1 is conducive to more precise setting of the RF allocation of each regulation branch.

[0030] Example 2 The apparatus described in Example 1 was applied to a 12-inch PECVD equipment from Dalian Haoyu. This equipment has two radio frequency (RF) sources: 13.56MHz and 400kHz, each equipped with a dedicated power regulation device. The impedance Z of the power regulation device for the 13.56MHz RF source is... f =13.45+j41.34, L=1.6uH, C1=2pF, C2=4pF, C3=8pF, C4=16pF, C5=32pF, all electronic switches are Infineon MOSFETs; the impedance of the power conditioning device of the 400kHz RF source is Z. f =10.73+j188.66, L=24uH, C1=20pF, C2=40pF, C3=80pF, C4=160pF, C5=320pF, and all electronic switches M are Infineon MOSFETs. Actual verification shows that this system is significantly superior to traditional solutions in terms of cost, reliability, adjustment speed, and size.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A power adjustment device for homogenizing wafer deposition, characterized in that, It includes several impedance adjustment branches; each impedance adjustment branch includes an inductor and a ceramic capacitor array connected in series; the ceramic capacitor array includes multiple ceramic capacitors connected in parallel, and each ceramic capacitor is equipped with an independent electronic switch at its front end; Each impedance regulation branch is connected in parallel with its corresponding branch load to form an RF regulation branch; The input terminals of the radio frequency conditioning branch are connected in sequence to the corresponding branch filters to form a series signal path. Each signal path controls the power distribution of a single wafer workstation, and multiple signal paths are configured in a parallel topology.

2. The power adjustment device for homogenizing wafer deposition according to claim 1, characterized in that, Each impedance adjustment branch has at least one electronic switch in the on state.

3. The power adjustment device for homogenizing wafer deposition according to claim 1, characterized in that, The electronic switch is located between the inductor and the corresponding ceramic capacitor.

4. The power adjustment device for homogenizing wafer deposition according to claim 1, characterized in that, The electronic switch is connected to the control system of the PECVD equipment.

5. The power adjustment device for homogenizing wafer deposition according to claim 1, characterized in that, The electronic switch is a MOSFET device, an IGBT, or a vacuum relay.

6. A PECVD device, characterized in that, The device comprises a power adjustment device for uniform wafer deposition as described in any one of claims 1-5.

7. A PECVD apparatus according to claim 6, characterized in that, It has two radio frequency sources, each equipped with a corresponding power regulation device to homogenize wafer deposition.

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