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CN-121974291-A - Manufacturing method for improving adhesion of MEMS gyroscope metal electrode

CN121974291ACN 121974291 ACN121974291 ACN 121974291ACN-121974291-A

Abstract

The application discloses a manufacturing method of a MEMS gyroscope metal electrode, which comprises the steps of carrying out first O 2 plasma and ICP etching pretreatment on the surface of a wafer, manufacturing a photoresist mask layer with an inverted trapezoid shape on the first surface of the wafer after pretreatment by using negative photoresist lithography, carrying out second O 2 plasma treatment on the surface provided with the photoresist mask layer, manufacturing a metal film layer on the surface subjected to the second O 2 plasma treatment by using an evaporation process, and removing the photoresist mask layer and the metal film layer by using a stripping process to obtain the MEMS gyroscope metal electrode.

Inventors

  • XING FEI
  • HE HUI
  • LIU RUITAO
  • WU XIAOYU
  • LI TENG
  • LI ANG
  • WU YU
  • JI XUEYANG

Assignees

  • 启元实验室

Dates

Publication Date
20260505
Application Date
20251230

Claims (9)

  1. 1. A method of manufacturing a MEMS gyroscope metal electrode, comprising: carrying out pretreatment on the surface of the wafer, wherein the pretreatment comprises a first O 2 plasma treatment and an ICP etching pretreatment; Manufacturing a photoresist mask layer with an inverted trapezoid shape on the first surface of the wafer after the surface is pretreated by using negative photoresist lithography; Preparing the first surface with the photoresist mask layer, and performing a second O 2 plasma treatment; Manufacturing a metal film layer on the first surface subjected to the second O 2 plasma treatment by using an evaporation process; and removing the photoresist mask layer and the metal film layer by using a stripping process to obtain the MEMS gyroscope metal electrode.
  2. 2. The method of claim 1, wherein the lift-off process comprises a combination of manual tearing and megasonic cleaning.
  3. 3. The method for manufacturing a metal electrode of a MEMS gyroscope according to claim 1, wherein the first O 2 plasma treatment has an O 2 flow of 200-400sccm, a power of 200-500W, and a time of 1-5min.
  4. 4. The method of manufacturing a metal electrode for a MEMS gyroscope according to claim 3, wherein the first O 2 plasma treatment has a flow rate of O 2 of 300sccm, a power of 300W, and a time of 2min.
  5. 5. The method for manufacturing a metal electrode of a MEMS gyroscope according to claim 1, wherein the flow rate of O 2 in the second O 2 Plasma treatment is 200-400sccm, the power is 200-500W, and the time is 1-5min.
  6. 6. The method of manufacturing a metal electrode for a MEMS gyroscope according to claim 5, wherein the second O 2 plasma treatment is performed at a flow rate of O 2 of 300sccm, a power of 300W, and a time of 2min.
  7. 7. The method for manufacturing a metal electrode of a MEMS gyroscope according to claim 1, wherein the time for the ICP etching pretreatment is 700-1000s, the intra-cavity pressure is 30-80mTorr, the oxygen flow is 200-400sccm, the radio frequency power is 200-500W, and the radio frequency bias voltage is 20-40W.
  8. 8. The method of claim 7, wherein the ICP etching pretreatment time is 900s, the intracavity pressure is 50mTorr, the oxygen flow is 300 seem, the rf power is 300W, and the rf bias is 30W.
  9. 9. The method of manufacturing a MEMS gyroscope metal electrode according to claim 1, wherein the metal thin film layer is selected from titanium or chromium.

Description

Manufacturing method for improving adhesion of MEMS gyroscope metal electrode Technical Field The application relates to the technical field of micro-mechanical gyroscopes, in particular to a manufacturing method for improving the adhesion of a metal electrode of a MEMS gyroscope. Background Microelectromechanical systems (Micro-Electro-MECHANICAL SYSTEM, MEMS) gyroscopes are commonly used to measure the rotational speed of an object such as an automobile, a drone, a satellite, etc., and typically form an active control system together with an accelerometer. For example, when turning, the system can automatically correct the magnitude of the lateral driving force by measuring the angular velocity through the gyroscope, thereby realizing the accuracy of planned route execution. MEMS gyroscopes typically have two-directional movable capacitive plates. The radial capacitive plates apply an oscillating voltage forcing themselves to perform radial movements, and the transverse capacitive plates measure the capacitance changes due to the transverse coriolis movements. Since the coriolis force is proportional to the angular velocity, the angular velocity can be calculated from the change in capacitance. Because the MEMS gyroscope has higher requirements on thermal stress, the metal electrode is manufactured by adopting a normal-temperature evaporation process in the aspect of process flow, and the phenomenon that the adhesion of the electrode is generally lower than that of the traditional sputtering process scheme occurs. In the multi-theory flow sheet process, the phenomenon of multiple electrode falling occurs when the device is packaged and wire-bonded. Disclosure of Invention In order to solve the above-mentioned shortcomings in the art, the present application aims to provide a manufacturing method for improving the adhesion of a metal electrode of a MEMS gyroscope. According to an aspect of the present application, a method of manufacturing a MEMS gyroscope metal electrode includes: Carrying out pretreatment on the surface of the wafer, wherein the pretreatment comprises a first O 2 plasma treatment and an ICP etching pretreatment; Manufacturing a photoresist mask layer with an inverted trapezoid shape on the first surface of the wafer after the surface is pretreated by using negative photoresist lithography; Preparing the first surface with the photoresist mask layer, and performing a second O 2 plasma treatment; Manufacturing a metal film layer on the first surface subjected to the second O 2 plasma treatment by using an evaporation process; and removing the photoresist mask layer and the metal film layer by using a stripping process to obtain the MEMS gyroscope metal electrode. According to some embodiments of the application, the stripping process includes a combination of manual gold stripping and megasonic cleaning. According to some embodiments of the application, the first O 2 plasma treatment is performed at a flow rate of O 2 of 200-400sccm, a power of 200-500W, and a time of 1-5min. According to some embodiments of the application, the first O 2 plasma treatment was performed at a flow rate of O 2 of 300sccm, at a power of 300W, and for a period of 2 minutes. According to some embodiments of the application, the second O 2 Plasma treatment has an O 2 flow of 200-400sccm, a power of 200-500W, and a time of 1-5min. According to some embodiments of the application, the second O 2 plasma treatment was performed at a flow rate of O 2 of 300sccm, a power of 300W, and a time of 2 minutes. According to some embodiments of the application, the ICP etch pretreatment time is 700-1000s, the chamber pressure is 30-80mTorr, the oxygen flow is 200-400sccm, the RF power is 200-500W, and the RF bias voltage is 20-40W. According to some embodiments of the application, the ICP etch pretreatment time is 900 seconds, the chamber pressure is 50mTorr, the oxygen flow is 300sccm, the RF power is 300W, and the RF bias is 30W. According to some embodiments of the application, the metal thin film layer is selected from titanium or chromium. Drawings FIG. 1 is a metal electrode on a MEMS gyroscope. FIG. 2 is a schematic diagram of a metal electrode preparation process (including negative photoresist lithography/metal film formation/metal lift-off). Fig. 3 is a schematic diagram of photoresist residue in the preparation of a metal electrode. Fig. 4 is a diagram of a manual stripping process in the preparation of a metal electrode. Fig. 5 is an AFM test chart before and after surface pretreatment according to an exemplary embodiment of the present application. Fig. 6 is a schematic illustration of a nano-scratch surface. FIG. 7 shows the results of nano scratch test. Detailed Description The technical solutions of the present application will be clearly and completely described in conjunction with the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present