Ion Bombardment in Silane VHF Deposition Plasmas

ABSTRACTThe measurement of mass resolved ion energy distributions at the grounded substrate in an RF glow discharge allows to determine the ion flux and the ion energy flux towards the surface of a growing hydrogenated amorphous silicon (a-Si:H) layer. This provides the means to study the influence of ions on the structural properties of a-Si:H. Here we focus on the α-γ’ transition as occurs in silane-hydrogen plasmas at an RF frequency of 50 MHz and a substrate temperature of 250 °C. The structural properties of the layers appear to depend on the kinetic energy of the arriving ions. This is supported by measurements of ion fluxes under other deposition conditions and by characterization of the corresponding layers. The influence of ions on the growth is discussed in terms of their flux, and the amount of delivered kinetic and potential energy to the growing film. The measurements suggest that a threshold energy of about 5 eV per deposited atom is needed for the construction of a dense amorphous silicon network.

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Structural properties of a-Si:H related to ion energy distributions in VHF silane deposition plasmas

Journal of Non-Crystalline Solids ◽

10.1016/s0022-3093(98)00453-0 ◽

1998 ◽

Vol 226 (3) ◽

pp. 205-216 ◽

Cited By ~ 41

Author(s):

E.A.G Hamers ◽

W.G.J.H.M van Sark ◽

J Bezemer ◽

H Meiling ◽

W.F van der Weg

Keyword(s):

Structural Properties ◽

Energy Distributions ◽

Ion Energy ◽

Ion Energy Distributions

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Growth and Characterization of Hydrogenated Amorphous Silicon using Liquid Organic Sources

MRS Proceedings ◽

10.1557/proc-219-697 ◽

1991 ◽

Vol 219 ◽

Author(s):

K. Gaughan ◽

S. Hershgold ◽

J. M. Viner ◽

P. C. Taylor

Keyword(s):

Thin Films ◽

Amorphous Silicon ◽

Hydrogenated Amorphous Silicon ◽

Wide Band ◽

Discharge Process ◽

Wide Band Gap ◽

Silicon Carbon ◽

Rf Glow Discharge ◽

Hydrogenated Amorphous

ABSTRACTThe uses of liquid sources such as tertiarybutylphosphine (TBP) for n-type doping in hydrogenated amorphous silicon (a-Si:H) and ditertiarybutylsilane (DTBS) and n-butylsilane (NBS) for hydrogenated amorphous silicon-carbon alloys (a-SiC:H) are described. A rf glow discharge process is employed to produce the doped a-Si:H and a-SiC:H thin films. Tertiarybutylphosphine (TBP) may ultimately be preferred over phosphine because TBP is less toxic, less pyrophoric and safer to implement. The gross doping properties of a-Si:H doped with TBP are the same as those obtained with phosphine, but there are some differences. N-butylsilane (NBS) and DTBS have been used to produce wide band gap (E04 3 ≈ eV) a-SiC:H.

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PREPARATION AND CHARACTERIZATION OF GRADED BANDGAP AMORPHOUS HYDROGENATED SILICON-SULFUR THIN FILMS

Modern Physics Letters B ◽

10.1142/s0217984992000545 ◽

1992 ◽

Vol 06 (08) ◽

pp. 469-475

Author(s):

M. HAMMAM

Keyword(s):

Amorphous Silicon ◽

Hydrogenated Silicon ◽

Amorphous Hydrogenated Silicon ◽

Graded Layers ◽

Rf Glow Discharge ◽

Optical Bandgaps ◽

Silicon Based ◽

Hydrogenated Amorphous ◽

Graded Bandgap

Compositionally graded hydrogenated amorphous silicon-sulfur alloys ( a-Si 1−x S x: H ) were grown by RF glow discharge decomposition of silane and hydrogen sulfide gases. Infrared spectra show clear evidence for the incorporation of sulfur in the form of Si-S bonds in the material. The graded bandgap films possess optical bandgaps ranging from 1.91 to 2.05 eV depending on the RF power. The compositionally graded layers display high photosensitivities indicating that they may be ideal candidates for use in amorphous silicon based tandem cells.

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