A new DRIE cut-off material in SOG MEMS process
-
Published:2023-04-01
Issue:4
Volume:44
Page:044101
-
ISSN:1674-4926
-
Container-title:Journal of Semiconductors
-
language:
-
Short-container-title:J. Semicond.
Author:
Si Chaowei,Fu Yingchun,Han Guowei,Zhao Yongmei,Ning Jin,Wei Zhenyu,Yang Fuhua
Abstract
Abstract
The silicon on glasses process is a common preparation method of micro-electro-mechanical system inertial devices, which can realize the processing of thick silicon structures. This paper proposes that indium tin oxides (ITO) film can serve as a deep silicon etching cut-off layer because ITO is less damaged under the attack of fluoride ions. ITO has good electrical conductivity and can absorb fluoride ions for silicon etching and reduce the reflection of fluoride ions, thus reducing the foot effect. The removal and release of ITO use an acidic solution, which does not damage the silicon structure. Therefore, the selection of the sacrificial layer has an excellent effect in maintaining the shape of the MEMS structure. This method is used in the preparation of MEMS accelerometers with a structure thickness of 100 μm and a feature size of 4 μm. The over-etching of the bottom of the silicon structure caused by the foot effect is negligible. The difference between the simulated value and the designed value of the device characteristic frequency is less than 5%. This indicates that ITO is an excellent deep silicon etch stopper material.
Subject
Materials Chemistry,Electrical and Electronic Engineering,Condensed Matter Physics,Electronic, Optical and Magnetic Materials
Reference20 articles.
1. High-performance 6-Axis MEMS inertial sensor based on through-silicon via technology;Acar;2016 IEEE International Symposium on Inertial Sensors and Systems,2016
2. 3-axis MEMS accelerometer-based implantable heart monitoring system with novel fixation method;Tjulkins;2013 IEEE 63rd Electronic Components and Technology Conference,2013
3. Tuning fork MEMS gyroscope for precision northfinding;Johnson;2015 DGON Inertial Sensors and Systems Symposium,2015
4. Glass isolated TSVs for MEMS;Kuisma;Proceedings of the 5th Electronics System-integration Technology Conference,2014
5. Epitaxially-encapsulated quad mass resonator with shaped comb fingers for frequency tuning;Taheri-Tehrani;2017 IEEE 30th International Conference on Micro Electro Mechanical Systems,2017