AFM study of surface finish improvement by ultrasound in the anisotropic etching of Si in KOH for micromachining applications
- 1 December 1997
- journal article
- Published by IOP Publishing in Journal of Micromechanics and Microengineering
- Vol. 7 (4) , 338-342
- https://doi.org/10.1088/0960-1317/7/4/010
Abstract
A new procedure for the production of smooth and defect-free surfaces in the anisotropic etching of silicon in alkaline solutions is described. It has been found that etching in an ultrasonic bath results in the facilitated detachment of hydrogen bubbles at the surface which is suggested to be one of the causes for surface roughening. In the presence of mild ultrasound radiation a significant improvement in surface finish of the orientation has been observed. The inclusion in the bath of oxygen and/or isopropanol results in root mean square roughness values smaller than 20 nm. The effectiveness of bath additives has been related to changes of the contact angle between the liquid/gas/etching interface. Quantitative determination of roughness and surface imaging have been obtained by atomic force microscopy; dissolution rates were studied by profilometry. Etching under ultrasound conditions and the use of additives does not change the etch kinetics, indicating that additional convection only changes hydrogen bubble detachment.Keywords
This publication has 20 references indexed in Scilit:
- Sonoelectrochemical processes: A reviewElectroanalysis, 1997
- An Atomic Force Microscopy Study on the Roughness of Silicon Wafers Correlated with Direct Wafer BondingJournal of the Electrochemical Society, 1996
- Surface Morphology of p‐Type (100) Silicon Etched in Aqueous Alkaline SolutionJournal of the Electrochemical Society, 1996
- Inhibition of pyramid formation in the etching of Si p(100) in aqueous potassium hydroxide-isopropanolJournal of Micromechanics and Microengineering, 1995
- Anisotropic etching of silicon at high pressureJournal of Electroanalytical Chemistry, 1993
- Chemical and electrochemical anisotropic dissolution of silicon in ethylenediamine + pyrocatechol + water mediaJournal of Electroanalytical Chemistry, 1993
- Influence of the supporting electrolyte and the pH on the electrooxidative activation of glassy carbon electrodesJournal of Electroanalytical Chemistry, 1992
- Anisotropic Etching of Crystalline Silicon in Alkaline Solutions: I . Orientation Dependence and Behavior of Passivation LayersJournal of the Electrochemical Society, 1990
- New explanation for the brightness of electrodeposits produced by ultrasoundUltrasonics, 1975
- Anisotropic Etching of SiliconJournal of Applied Physics, 1969