SI-29 MAGNETIC-RESONANCE STUDY OF AMORPHOUS HYDROGENATED SILICON PLASMA DEPOSITED AT 50-DEGREES-C

We deposit compact amorphous hydrogenated silicon (a-Si:H) films at 50-degrees-C, using low silane partial pressures in silane/hydrogen reaction mixtures. The Si-29 chemical shift and infrared signature of our films are strongly affected by the silane feed partial pressure, but are insensitive to the hydrogen feed partial pressure, indicating that hydrogen ''etching'' does not play a significant role in the film growth process. Interestingly, the Si-29 chemical shift and infrared signature of our compact 50-degrees-C films are similar to those of a-Si:H films deposited at standard ''optimum'' conditions, but the electronic properties are very different. Upon thermal annealing at 150-degrees-C for 3 h, the spin defect density may be reduced by as much as 2 orders of magnitude, while the hydrogen content, Si-29 chemical shift and infrared signature remain unchanged. Therefore, it seems possible to first grow a compact silicon network structure in a-Si:H at 50-degrees-C, and then equilibrate the electronic structure at 150-degrees-C, without significantly altering the silicon network.