D-SI(111)(1X1) SURFACE FOR THE STUDY OF SILICON ETCHING IN AQUEOUS-SOLUTIONS

Deuterium-terminated Si(lll) surfaces are formed in a solution of KF a nd DCl in D2O. Infrared spectroscopy shows the surface to be flat with a D-Si bond normal to the surface. H-Si is formed preferentially to D -SI in a mixture of protonated and deuterated etchants. From the D-to- H exchange rate and the terrace width, we estimate the rate of the ste pflow etching process to be 4.2 nm/s in Ar-sparged 40% NH4F solution. Dissolved O-2 in the solutions substantially increases the D-to-H exch ange rate by the formation of pits and the consequent increase in the step density. (C) 1998 American Institute of Physics.