Effects on ellipsometric parameters caused by heat treatment of silicon (111) surface

Abstract

Heating of a silicon single crystal introduces a surface roughness. Crystals are heated for periods of 45 set in the temperature range from 560 to 1150°C. Using ellipsometry, Auger electron spectroscopy, mass spectroscopy and micrography it has been shown that the changes in the ellipsometric parameters are caused by surface roughness which in turn is strongly related to the sublimation of silicon during heating. The relation between surface roughness and temperature of the crystal during the heating is not linear.

Ellipsometric Study of Orientation‐Dependent Etching of Silicon in Aqueous KOH

“…Preser~tly available theories (29) treating scattering induced depolarization in ellipsometry are restricted to the small-roughness (~ << X/10) limit and/or the small-slope regime (tan ~ << 1, where fi is the angle between the local surface tangent and the average surface plane). We note that several studies (30)(31)(32)(33) of macroscopically roughened Si surfaces (by chemical or thermal treatment) reported ~ and A decreasing with increasing roughness.…”

Adsorption of atomic oxygen (N2O) on a clean Si(100) surface and its influence on the surface state density; A comparison with O2

“…An anneal temperature of maximal 800°C was chosen, since annealing a silicon crystal in vacuum above 800°C results in irreversible changes of the surface texture, as shown by a recent spectroscopic ellipsometry study 1251. At temperatures around 109O*C the silicon surface even starts to appear milky [26,27].…”