ABSTRACTPlasma deposition using silane and germane is extensively used for depositing amorphous (Si,Ge) films and devices, and has the potential of also being used for making crystalline films. In this paper, we report results on the electrical and optical characterization of germane plasmas using a Langmuir probe set-up and optical emission spectroscopy. The plasma studied was an electron-cyclotron-resonance plasma. For the first time ever, we have detected the characteristic 246 nm GeH emission peak in the plasma. The GeH emission peak is suppressed significantly when small quantities of hydrogen are added as a diluent gas. We have also studied the effect of adding a voltage bias to the substrate on the plasma properties. We find that adding voltage bias does not simply change the effective ion energy impinging on the substrate, as is usually assumed, but also changes all the plasma properties, including the density of neutral, excited H radicals arriving at the growing surface.
03/02046 Plasma deposition of thin film silicon: kinetics monitored by optical emission spectroscopy
