Process-induced stress and hydrogen effects on monolithic integrated BiCMOS-MEMS resonators

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• 作者：Danqi Zhao ; Xia Zhang ; Jun He ; Xian Huang ; Fang Yang ; Peng Liu ; Dacheng Zhang
• 关键词：CMOS-MEMS ; Monolithic integration ; Stress ; Hydrogen ; Resonator sensor
• 刊名：Sensors and Actuators A: Physical
• 出版年：1 November, 2013
• 年：2013
• 卷：202
• 期：Complete
• 页码：75-84
• 全文大小：4394 K

文摘

In this article, the simultaneous fabrication of MEMS and Bi-CMOS components on a monolithic integrated micro-cantilever resonator is investigated. Surface micromachining method for cantilever fabrication has been merged with conventional CMOS process, and release of MEMS structure is conducted after CMOS process. We for the first time propose the additive effects of hydrogen and MEMS steps induced mechanical stress on the IC performance, and at the same time provide a re-adjusting method for integrated process design, in which the NMOS/PMOS threshold voltage is re-adjusted to symmetry by utilizing the MEMS-process-induced IC performance degradation. On-chip digital/analog Bi-CMOS circuits function properly as demonstrated. The proposed re-adjustment process, suitable for fabrications with a variety of design CMOS-MEMS integrated process flexibilities, has the potential to fabricate integrated devices (high quality factor variable capacitors, micromirror arrays and multi-axis gyroscopes etc.).