Very homogeneous
SiO2
layers were prepared by rf sputtering of
SiO2
in Ar or Si in
O2
with Ar on Si substrates which had been cleaned in situ by sputter etching. After a short anneal in
N2
(20 min at 1050°C and a 10 min postmetallization anneal at 500°C), surface charge, surface‐state density, and stability were similar to those reported for good, thermally grown oxides. Best results were obtained with reactively sputtered
SiO2
.