Thermal Induced Conductance of KOH Etched Silicon Surface

Abstract

Anisotropic KOH etch rate of silicon is found to vary with thermal agitation along with
crystal plane orientation. In this work, experimental results of etch rate is found with their
unusual values of activation energy along different planes. The various sites that an atom
can occupy are not equivalent of their energy; some are more favorable to removal than
others. In this paper attention is given to demonstrate thermal activation influences the
behavior of etching mechanism as well as surface morphology. Low-voltage contact mode
atomic force microscopy (AFM) has been employed to analyze the morphology of the
etched silicon surface at relevant temperature. With temperature evolution the width of the
forbidden energy gap is going down and hence conductivity is rises.

Keywords: Anisotropy; Etch rate; MEMS; SOI; AFM; Contact mode.

DOI: 10.3126/kuset.v6i1.3314

Kathmandu University Journal of Science, Engineering and Technology Vol.6(1) 2010, pp79-88