The Chemistry of Etching: Understanding Kinetic Surface Morphologies on an Atomic Scale

Cornell University, Ithaca NY

Investigators

Abstract

This research project, supported in the Analytical and Surface Chemistry Program, addresses the mechanism of etching of silicon surfaces. Using a combination of scanning probe microscopy and kinetic Monte Carlo simulation methods, Professor Hines and her colleagues in the Department of Chemistry at Cornell University are investigating the effect of etching conditions on the silicon surface morphology. Experiments are addressing the aqueous etching of the Si(111) surface by KOH solution, as well as the anodic etching of silicon surfaces used to create porous silicon materials. The effects of step orientation, step density, and silicon dopant, as well as etchant composition and concentration are being examined. Results of this work are important for the design of nanomaterial technologies, as well as for the development of electronic materials processing strategies. Information about how chemical etchants remove material from the surface of a silicon wafer is important for the design of processes to make micro-electromechanical (MEMS) devices, and for the production of electronic and photonic devices. The work of this research project is directed to developing an understanding of the aqueous and electrochemical etching of silicon, with the goal of developing a microscopic understanding of what controls the atomic and nano-scale morphology of the etched surface. With the support of the Analytical and Surface Chemistry Program, Professor Hines and her colleagues at Cornell, are using a combination of microscopy and computer simulation to obtain this information.