Techniques for Measuring the Composition of Hydrogenated Amorphous Silicon-Germanium Alloys (Preprint)

We grow hydrogenated amorphous silicon-germanium alloys by the hot-wire chemical vapor deposition technique at deposition rates between 0.5 and 1.4 nanometers per second. We prepared a set of these alloys to determine the concentrations of the alloying elements as measured by various techniques. This set consists of samples throughout the range of germanium alloying from 0% (a-Si:H) to 100%(a-Ge:H). We find that by making the appropriate calibrations and corrections, our compositional measurements agreement between the various techniques. Nuclear reaction analysis, Fourier transform infrared spectroscopy, and secondary ion mass spectrometry (SIMS) all yield similar hydrogen contents, within ??20% for each sample. Electron probe micro-analysis (EPMA) and SIMS yield silicon andgermanium contents within ??7% of each other with results being confirmed by Rutherford backscattering. EPMA oxygen measurements are affected by highly oxidized surface layers, thus these data show larger O concentrations than those measured by SIMS.