Photoemission spectroscopy of heterojunctions of amorphous hydrogenated silicon with silicon oxide and nitride

A study of the growth and electronic structure of a-Si:H/a-SiN/sub x/:H and a-Si:H/a-SiO/sub x/:H heterojunctions by photoemission spectroscopy is discussed. The interfaces in a-Si:H/a-SiO/sub x/ are atomically abrupt, except for the SiO/sub x/ on the Si interface which is graded over approximately 3 AA due to plasma oxidation. The offset energies between the a-Si:H valence band and those of a-SiN/sub x/:H and a-SiO/sub x/:H are 1.2 and 4.0 eV, respectively. Extra H( approximately 2*10/sup 15/) is incorporated in the Si on the SiN/sub x/ interface region. The hole wave functions in a-Si:H are localized on a scale of 1-2 interatomic distances.<
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