Surface Flatness Improvement in Si Anisotropy Etching Process Utilizing Ultrasonic Wave Technology

초음파 기술을 이용한 실리콘 이방성 식각 공정에서의 표면 평탄화 향상 연구

  • Published : 2005.07.07

Abstract

In this study, we optimized the process of Si anisotropy etching by combing tetramethyl ammonium hydroxide (TMAH) etching process with ultrasonic wave technology. New ultrasonic TMAH etching apparatus was developed and it was used for fabricating a $20{\mu}m$ thick diaphragm for Si piezoresistive pressure sensors. Based on comparison study on etch rate and surface flatness, it was observed that the Si anisotropy etching methode with new ultrasonic TMAH etching apparatus (at 40 kHz/ 500 watt) was superior to conventional etching methods with TMAH or TMAH+ammonium persulfate(AP) solutions.

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