Towards a fast determination of the hydrogen concentration in thin passivating a-Si:H layers using GD-OES

In this contribution, the measurement of the hydrogen concentration in thin passivating amorphous silicon (a-Si:H) layers using Glow Discharge Optical Emission Spectroscopy (GD-OES) is suggested. Usually GD-OES hydrogen measurements suffer from additional signals from atmospheric contaminations, especially from H2O desorbed on the surfaces of such thin layers. This issue is addressed by the deposition of a hydrogen-free copper buffer layer on top, which provides a delay between sputtering the sample surface and the a-Si:H layer itself. Thus the signals from the atmospheric contaminations and from the a-Si:H layer itself are separated. The contamination-free hydrogen signals of the thin a-Si:H layers are eventually calibrated to average hydrogen concentrations.