Editors : Y. Hamakawa, P. G. LeComber, A. Madan, P. C. Taylor, M. J. Thompson
a1 Inst. f. Physikalische Elektronik, Universitaet Stuttgart, Pfaffenwald-ring 47, D-7000 Stuttgart 80, F.R. Germany
A vacuum UV-photo-CVD reactor for direct decomposition of Si2H6, SiH4, GeH4, and B2H6 for a-Si:H, a-Ge:H, and a-SiGe:H deposition has been operated with a large area dielectric-barrier discharge lamp emitting excimer radiation of Xe (7.3eV), Kr (8.6eV), or Ar (9.8eV).
It is shown that the deposition process (Si2H6 or GeH4 at 0.5 mbar) is governed by the diffusion of long-lifetime radicals.
High quality undoped and p-type doped a-Si:H has been deposited from Si2H6 and B2H6 with the Xe lamp spectrum (σph/σ≈106 at Eg=1.9eV) and film growth rates of up to 5 nm/min have been achieved.