Surface/bulk micromachining (SBM) process and deep trench oxide isolation method for MEMS
Surface/bulk micromachining (SBM) process and deep trench oxide isolation method for MEMS
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DOI：
10.1109/iedm.1999.824248
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
Sangwoo Lee;Sangjun Park;Dong-il Cho;Yongsoo Oh
中科院分区：
文献类型：
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作者：
Sangwoo Lee;Sangjun Park;Dong-il Cho;Yongsoo Oh
本文提出了一种用单晶硅微加工释放结构的新方法，以及一种用深沟槽氧化物电隔离释放结构的新方法。所开发的表面/体微机械加工（SBM）工艺利用（111）硅晶片。使用反应离子蚀刻机来限定结构图案。然后，用氧化膜钝化图案以及侧壁，并且在期望的区域暴露裸硅。暴露的裸硅被进一步反应离子蚀刻，这限定了牺牲间隙尺寸。通过在含水碱性蚀刻剂中底切暴露的体硅侧壁，可以制造干净地释放的微结构。为了感测或静电致动释放的微结构，深沟槽氧化物隔离方法被开发并成功地应用于致动梳状驱动致动器。所开发的深沟槽氧化物隔离的SBM工艺允许制造具有低寄生电容的单晶硅MEMS。
This paper presents a new method for micromachining released structures with single crystal silicon, as well as a new method for electrically isolating the released structures with a deep trench oxide. The developed surface/bulk micromachining (SBM) process utilizes (111) silicon wafers. The structural patterns are defined using a reactive ion etcher. Then, the patterns as well as sidewalls are passivated with an oxide film, and bare silicon is exposed at desired areas. The exposed bare silicon is further reactive ion etched, which defines sacrificial gap dimensions. By undercutting the exposed bulk silicon sidewalls in an aqueous alkaline etchant, cleanly released microstructures can be fabricated. For sensing or electrostatic actuation of released microstructures, a deep trench oxide isolation method is developed and applied successfully to actuate a comb-drive actuator. The developed SBM process with deep trench oxide isolation allows fabricating single crystal silicon MEMS with a low parasitic capacitance.