Published online by Cambridge University Press: 28 February 2011
The incorporation of hydrogen into silicon nitride films grown downstream from an electron cyclotron resonance (ECR) plasma decreased rapidly with increasing substrate temperature (100–600°C). Fourier transform infra-red (FTIR) spectroscopy showed that the hydrogen in the as-grown material was primarily bonded to nitrogen. However, an applied bias of -200 V caused an increase in the number of Si-H bonds relative to N-H bonds, as a result of increased ion-beam damage. In addition, ion irradiation of an as-grown film with 175 keV Ar+ at room temperature showed that H transferred from N-H bonds to Si-H bonds without a loss of H. Elastic recoil detection (ERD) and FTIR of thermally annealed films showed that the stability of H incorporated during deposition increased with deposition temperature, and that the N-H bond was more stable than the Si-H bond above 700°C. Deuterium plasma treatments, at 600°C, of annealed films caused isotopic substitution with a conservation of bonds. Therefore, hydrogen loss from annealed films is apparently accompanied by a reduction in dangling bonds.