LOW-TEMPERATURE SI CRYSTAL-GROWTH BY ALTERNATING DEPOSITION AND HYDROGEN ETCHING SEQUENCES AND ITS APPLICATION TO THE P-LAYER OF A-SI-H SOLAR-CELLS

Low temperature silicon crystal growth by alternating deposition and hydrogen etching sequences has been studied. The large area remote ECR H-2 plasma was used as an atomic hydrogen source. Epitaxial, polycrystalline, and microcrystalline Si thin films have been obtained below 400 degrees C corresponding to various deposition conditions and kinds of substrates. Epitaxial films with electron mobilities exceeding 800 cm(2)/Vs were obtained on Si(100) substrates. By applying this method, very thin p-type microcrystalline Si films have been prepared on SnO2 substrates below 200 degrees C. The cross-sectional TEM micrographs showed that the longitudinal crystal size of microcrystalline on SnO2 substrates was about 100-200 Angstrom. The a-Si:H solar cells with p-type microcrystalline Si had a higher open-circuit voltage than that of conventional cells by as much as 0.02-0.04 eV.