Amorphous silicon film

A. J. Bevolo, M. L. Albers, H. R. Shanks, and J. Shinar. J. Appl. Phys. 62, 1240, 1987. VEELS in fixed-spot mode to depth profile hydrogen in amorphous silicon films to determine hydrogen mobility at elevated temperatures. 

Delahoy, A., Doele, B., Ellis, F., Ramaprasad, K., Tonon, T., and Van Dine, J., Amorphous Silicon Films and Solar Cells Prepared by Mercury-Sensitized Photo-CVD of Silane and Disilane, Materials Issues in Applications of Amorphous Silicon Technology, (D. Adler, et al., eds), MRS Proc., (49) 33-39 (1985)... 

Selected Properties of Device Quality Hydrogenated Amorphous Silicon Films... 

The low background pressure (10 mbar) together with the purity of the gases used ensures a low concentration of contaminants. Amorphous silicon films made in the intrinsic reactor have been analyzed by using ERD, which is available in our laboratory [114]. The determined oxygen content in these films typically is lower than 3 x lO cm - which is somewhat lower than the values required for obtaining device quality films reported by Morimoto et al. [167]. 

In the early 1970s, Spear and coworkers (Spear, 1974 Le Comber et al., 1974), although unaware of the presence of hydrogen, demonstrated a substantial reduction in the density of gap states (with a corresponding improvement in the electronic transport properties) in amorphous silicon films that were deposited from the decomposition of silane (SiH4) in an rf glow discharge. 

Absorption characteristics, of hydrogenated amorphous silicon films, 22 133-134 Absorption coefficients, 23 126 Absorption-desorption towers, 10 614 Absorption maxima, vinylene shifts of,... 

For these conditions, Armaou and Christofides [4] determine the thickness profile, in Fig. 10.4-3, for the amorphous silicon film after 60 s, when the average thickness reaches 500 A. When characterizing the non-uniformity of the film, the sharp increase in thickness calculated near the outer edge of the wafer is assumed to be due to the boundary conditions, which assume step changes to zero concentrations at the edge. Brass and Lee (2003) disregard the profile from r = 3.6 to 4 cm, and compute the non-uniformity as ... 

Becanse fabrication costs show the potential for snbstantial reduction, and because amorphous silicon films are much more readily created in the form of large-area panels than are their crystalline counterparts, it is anticipated that amorphous devices may command a snbstantial share of the commercial market, once the necessary development stages have been accomplished. Already, devices snch as calcnlators, television sets, and tape recorders have been prodnced with amorphons silicon solar panels as the power source, and an experimental solar-powered honsing nnit has been constructed. 

The formation of amorphous silicon films by electrodeposition from non-aqueous solutions have also been studied [18, 19]. For example, a flat homogeneous silicon film of about 0.25 pm thick can be deposited from 0.2 M SiHCl3-0.03 M Bu4NBr-THF bath on the cathode of Pt, Au, Cu, GC, ITO, etc., although small amounts of impurities (O, C, Cl) are contained. Their use in photovoltaic or photoelectrochem-ical solar cells are promising, although there are still many problems to be solved. 

Janai and Moser (1982) have used chemical-vapor-deposited amorphous silicon films that were deposited at 600°C on silica (fused quartz) substrates. Information was recorded in films with thickness d between 2500 and 5000 A by irradiation with a ruby laser pulse of 50 nsec duration and an energy density ranging from 0.4 to 1.5 J cm-2. The upper energy limit is known to be above the threshold for laser melting in a-Si (Baeri et al., 1980). To determine the optical transmission density difference... 

Suzuki, R., Kobayashi, Y., Mikado, T., Matsuda, A. et al. (1991) Characterization of hydrogenated amorphous silicon films by a pulsed positron beam , Jpn. J. Appl. Phys. 30,2438. 

Kessels, W. M. M., Leewis, C. M., van de Sanden, M. C. M., and Schram, D. C., Formation of cationic silicon clusters in a remote silane plasma and their contribution to hydrogenated amorphous silicon film growth. 7. Appl. Phys. 86, 4029 039 (1999b). 

Von Keudell, A., and Abelson, J. R., Direct insertion of SiH radicals into strained Si-Si surface bonds during plasma deposition of hydrogenated amorphous silicon films. Phys. Rev. B 59,5791-5798 (1999). 

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