| 摘要 |
A thin silicon-rich nitride film (e.g., having a thickness in the range of around 100A to 10000A) deposited using low-pressure chemical vapor deposition (LPCVD) is used for etch stop during vapor HF etching in various MEMS wafer fabrication processes and devices. The LPCVD silicon-rich nitride film may replace, or be used in combination with, a LPCVD stoichiometric nitride layer in many existing MEMS fabrication processes and devices. The LPCVD silicon-rich nitride film is deposited at high temperatures (e.g., typically around 650-900 degrees C.). Such a LPCVD silicon-rich nitride film generally has enhanced etch selectivity to vapor HF and other harsh chemical environments compared to stoichiometric silicon nitride and therefore a thinner layer typically can be used as an embedded etch stop layer in various MEMS wafer fabrication processes and devices and particularly for vapor HF etching processes, saving time and money in the fabrication process.
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