INTERPRETATION OF ELLIPSOMETRY MEASUREMENTS TAKEN FROM ANNEALED HEAVILY ARSENIC-IMPLANTED SILICON

Ellipsometry measurements taken from annealed arsenic-implanted silico n substrates, and from the native oxides forming on these surfaces, ar e interpreted with the use of the ancillary techniques Auger electron spectroscopy (AES) and transmission electron microscopy (TEM). It is d emonstrated that erroneous over estimates of initial and time-evolved native oxide thicknesses are made by ellipsometry when common assumpti ons for bare undoped silicon surfaces are used. It is further shown th at discrepancies between common interpretations of ellipsometric data and AES-TEM can be reconciled by invoking a shift in substrate refract ive index and extinction coefficient with increasing dopant dose.