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Title: Deposition of device quality, low hydrogen content, hydrogenated amorphous silicon at high deposition rates

A method of fabricating device quality, thin-film a-Si:H for use as semiconductor material in photovoltaic and other devices, comprising in any order; positioning a substrate in a vacuum chamber adjacent a plurality of heatable filaments with a spacing distance L between the substrate and the filaments; heating the filaments to a temperature that is high enough to obtain complete decomposition of silicohydride molecules that impinge said filaments into Si and H atomic species; providing a flow of silicohydride gas, or a mixture of silicohydride gas containing Si and H, in said vacuum chamber while maintaining a pressure P of said gas in said chamber, which, in combination with said spacing distance L, provides a P.times.L product in a range of 10-300 mT-cm to ensure that most of the Si atomic species react with silicohydride molecules in the gas before reaching the substrate, to thereby grow a a-Si:H film at a rate of at least 50 .ANG./sec.; and maintaining the substrate at a temperature that balances out-diffusion of H from the growing a-Si:H film with time needed for radical species containing Si and H to migrate to preferred bonding sites.
Inventors:
 [1];  [2];  [3];  [1];  [4];  [1]
  1. (Golden, CO)
  2. (Rotterdam, NL)
  3. (Louisville, CO)
  4. (Lafayette, CO)
Issue Date:
OSTI Identifier:
874825
Assignee:
Midwest Research Institute (Kansas City, MO) NREL
Patent Number(s):
US 6468885
Contract Number:
AC36-99GO10337
Research Org:
Midwest Research Institute
Country of Publication:
United States
Language:
English
Subject:
deposition; device; quality; hydrogen; content; hydrogenated; amorphous; silicon; rates; method; fabricating; thin-film; a-sih; semiconductor; material; photovoltaic; devices; comprising; positioning; substrate; vacuum; chamber; adjacent; plurality; heatable; filaments; spacing; distance; heating; temperature; obtain; complete; decomposition; silicohydride; molecules; impinge; atomic; species; providing; flow; gas; mixture; containing; maintaining; pressure; combination; provides; ptimesl; product; range; 10-300; mt-cm; ensure; react; reaching; grow; film; rate; 50; angsec; balances; out-diffusion; growing; time; radical; migrate; bonding; sites; amorphous silicon; semiconductor material; vacuum chamber; hydrogenated amorphous; atomic species; deposition rate; hydrogen content; device quality; /438/