Production and Annealing of Color Centers in rf Sputtered SiO2 Films

Publisher Website
Google Scholar
Abstract
Radio‐frequency sputtered SiO2 films can be made that contain a variety of optical absorption bands and electron spin resonance centers. In addition to absorption bands at 5.1, 5.8, and 7.6 eV that are typical of irradiated fused SiO2, two new absorption bands have been found. The G band at 5.4 eV and the H band at 6.55 eV are present in certain sputtered SiO2 films and develop further when they are annealed in forming gas or N2. The occurrence of these bands and the density of paramagnetic centers produced in SiO2 films when they are sputtered under different deposition conditions has been studied. The effect of annealing to 950°C in N2, O2, and forming gas on optical absorption bands and ESR centers has been determined. Absorption bands appear to be associated with oxygen deficiency in the sputtered SiO2 films since they will anneal completely at 930°C in oxygen. Hydrogen plays an important role in annealing of the B1 band at 5.1 eV, the E1′ band at 5.8 eV, and all the ESR centers. They anneal at 200°C lower temperatures in forming gas, compared to annealing in N2. The OH content, refractive index, Ar content, density, and etch rates of sputtered SiO2 films have also been measured. The properties of the film show the importance of plasma radiation and resputtering in determining film properties. Wide variations in optical absorption and ESR are observed in samples deposited under nominally identical conditions.

This publication has 32 references indexed in Scilit: