Li W.J., Liu J., Shih J.C., Mai J.D., Ho C-M., Liu J., Tai Y-C.
UC-Los Angeles, US
Keywords: etchingmodel, HF-PSG, MEMS-diaphragm, sacrificial-etching, surfacemicromachining
Chemical etching of sacrifeial layers is a widely used technique in surface micromachining Etch rate prediction of the sacrif cial layer in an etchant is critical for optimizing a giving fabrication process. This paper presents a moving-boundary numerical scheme to predict the motion of a hydrofluoric (HF) acid and phosphosilicate-glass fPSG) etching interface. Results showed the prediction of the etch front pmpagation for square structures is universally possible for HF concentrations ranging from 3 to 49?/a In the process, some physical mechanisms governing the HFPSG etching phenomenon were elucidated The results also indicate that the moving-boundary scheme can be extended to predict the etch rate of more complex geometries.
Journal: TechConnect Briefs
Volume: Technical Proceedings of the 1998 International Conference on Modeling and Simulation of Microsystems
Published: April 6, 1998
Pages: 59 - 64
Industry sector: Sensors, MEMS, Electronics
Topics: Informatics, Modeling & Simulation, Modeling & Simulation of Microsystems
ISBN: 0-96661-35-0-3