Defect formation during deposition of undoped a-Si:H by PECVD
- Science Univ. of Tokyo, Noda, Chiba (Japan). Dept. of Materials Science and Technology
Dependence of the as-grown defect concentration in PECVD undoped a-Si:H on the deposition parameters, i.e., substrate temperature and precursor density in the plasma produced by H{sub 2} dilution of SiH{sub 4} gas, is investigated. It is found that the defect density behaves similarly to the concentration of SiH{sub 2} configuration in the films deposited at substrate temperatures below 300 C. The defect concentration, however, varies proportionally to about the 3rd to 4th power of the SiH{sub 2} concentration depending on the deposition condition. Based on the surface reaction mechanism proposed in the previous paper, a large enthalpy change is expected to accompany the bimolecular reaction of the adsorbed SiH{sub 3} radicals, which incorporates the SiH{sub 2} configuration into the network. Characteristics of the defect formation caused by the breaking Si-Si bond near the growing surface owing to this energy is compared with those of the Staebler-Wronski effect. Both similarity in dependence on H atom concentration and difference in annealing temperature are discussed. It is concluded that the as-grown defects are most likely formed during deposition owing to the large enthalpy change accompanying the bimolecular surface reaction.
- OSTI ID:
- 527688
- Report Number(s):
- CONF-960401-; ISBN 1-55899-323-1; TRN: IM9741%%116
- Resource Relation:
- Conference: Spring meeting of the Materials Research Society (MRS), San Francisco, CA (United States), 8-12 Apr 1996; Other Information: PBD: 1996; Related Information: Is Part Of Amorphous silicon technology -- 1996; Hack, M. [ed.] [dpiX, Palo Alto, CA (United States)]; Schiff, E.A. [ed.] [Syracuse Univ., NY (United States)]; Wagner, S. [ed.] [Princeton Univ., NJ (United States)]; Schropp, R. [ed.] [Utrecht Univ. (Netherlands)]; Matsuda, Akihisa [ed.] [Electrotechnical Lab., Tsukuba (Japan)]; PB: 929 p.; Materials Research Society symposium proceedings, Volume 420
- Country of Publication:
- United States
- Language:
- English
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