Systematic study of the etching characteristics of Si{111} in modified TMAH

Micro & nano letters

article

Veerla Swarnalatha¹  Prem Pal¹  Ashok Kumar Pandey²  Avvaru Venkata Narasimha Rao¹  Yan Xing³  Hiroshi Tanaka⁴  Kazuo Sato⁴ 

[1] MEMS and Micro/Nano Systems Laboratory, Department of Physics, Indian Institute of Technology Hyderabad;Department of Mechanical and Aerospace Engineering, Indian Institute of Technology Hyderabad;Department of Mechanical Engineering, Southeast University;Deptartment of Mechanical Engineering, Aichi Institute of Technology

关键词: microfabrication;    surface morphology;    elemental semiconductors;    silicon;    micromachining;    sputter etching;    nitrogen compounds;    hydrogen compounds;    oxygen compounds;    complex microstructures;    tetramethyl-ammonium hydroxide;    improved etching characteristics;    freestanding microstructures;    suspended microstructures;    modified TMAH solution;    silicon wet bulk micromachining;    Si;    NH2OH;   

DOI  :  10.1049/mnl.2019.0443

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

Wet bulk micromachining on Si{111} is done to fabricate simple to complex microstructures for applications in sensors and actuators. In this work, it has been performed a systematic study of Si{111} in modified 5 wt% tetramethyl-ammonium hydroxide (TMAH) with varying concentration of NH 2 OH for achieving improved etching characteristics especially high lateral undercutting at mask edges aligned along non-〈110〉 directions. The concentration of NH 2 OH is varied from 5 to 20% in step of 5%. The lateral undercutting, which is highly desirable for the quick release of freestanding microstructures from the substrate, is increased considerably with the addition of NH 2 OH in TMAH solution. In addition, the incorporation of NH 2 OH improves etched surface morphology. Moreover, the effect of etchant ageing on the etching characteristics is investigated. Suspended microstructures are fabricated to demonstrate the application of modified TMAH solution for silicon wet bulk micromachining. The results presented in this work are highly useful where Si{111} wafer is used for the fabrication of microstructures.

【 授权许可】

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