Real timeinsituobservation of the film growth of hydrogenated amorphous silicon by infrared reflection absorption spectroscopy

1990 ◽  
Vol 56 (16) ◽  
pp. 1540-1542 ◽  
Author(s):  
Yasutake Toyoshima ◽  
Kazuo Arai ◽  
Akihisa Matsuda ◽  
Kazunobu Tanaka
Keyword(s):  
Amorphous Silicon ◽  
Absorption Spectroscopy ◽  
Film Growth ◽  
Hydrogenated Amorphous Silicon ◽  
Infrared Reflection Absorption Spectroscopy ◽  
Infrared Reflection ◽  
Hydrogenated Amorphous

Reduction of the Defect Density in a-Si:H Deposited at ≤250°C

1993 ◽  
Vol 297 ◽  
Author(s):  
Hitoshi Nishio ◽  
Gautam Ganguly ◽  
Akihisa Matsuda
Keyword(s):  
Diffusion Coefficient ◽  
Amorphous Silicon ◽  
Surface Diffusion ◽  
Film Growth ◽  
Defect Density ◽  
Hydrogenated Amorphous Silicon ◽  
Device Fabrication ◽  
Surface Diffusion Coefficient ◽  
Hydrogenated Amorphous ◽  
Substrate Temperatures

We present a method to reduce the defect density in hydrogenated amorphous silicon (a-Si:H) deposited at low substrate temperatures similar to those used for device fabrication . Film-growth precursors are energized by a heated mesh to enhance their surface diffusion coefficient and this enables them to saturate more surface dangling bonds.

scholarly journals Anisotropy in Hydrogenated Amorphous Silicon Films as Observed Using Polarized Ftir-Atr Spectroscopy

1999 ◽  
Vol 557 ◽  
Author(s):  
J. D. Webb ◽  
L. M. Gedvilas ◽  
R. S. Crandall ◽  
E. Iwaniczko ◽  
B. P. Nelson ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Film Growth ◽  
Crystalline Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Impurity Band ◽  
Attenuated Total Reflection ◽  
Structural Anisotropy ◽  
Si Films ◽  
Polarized Ftir ◽  
Hydrogenated Amorphous

AbstractWe used polarized attenuated total reflection (ATR) measurements together with Fourier transform infrared (FTIR) spectroscopy to investigate the vibrational spectra of hydrogenated amorphous silicon (a-SiHx) films 0.5-1.0 microns in thickness. We deposited the films using hot-wire or plasma-enhanced chemical vapor deposition methods (HWCVD or PECVD, respectively) on crystalline silicon and cadmium telluride substrates. Our ATR technique gave a spectral range from 2100-400 cm-1, although the Si-H wagging mode absorption band at 640 cm-1 was somewhat distorted in the a-SiHx/Si samples by impurity and lattice absorption in the silicon ATR substrates. We report the identification of a Si-O-C impurity band with maximum intensity at 1240-1230 cm-1. The assignment of this band to a Si-O-C vibration is supported by secondary-ion mass spectrometry (SIMS) measurements. Our polarized FTIR-ATR spectra of HWCVD and PECVD a-SiHx films on <111> Si ATR substrates show that the impurity dipoles are oriented strongly parallel to the film growth direction. The wagging mode absorbance band is more intense in the film plane. This trend is less pronounced for the Si-H stretching vibrations. These observations are consistent with some degree of anisotropy or medium-range order in the films. The anisotropy in the Si-H bands may be related to residual stress in the films. Our scanning electron microscopy (SEM) analyses of the samples offer additional evidence of bulk structural anisotropy in the a-SiHx/Si films. However, the Si-O-C impurity band was not observed in the polarized ATR-FTIR spectra of the a-SiHx/CdTe samples, thus indicating that the Si substrates influence formation of the impurity in the a-SiHx/Si films.

In-Situ Monitoring of Surface Hydrogen on the a-SiGe:H Films

1997 ◽  
Vol 467 ◽  
Author(s):  
Y. Toyoshima ◽  
G. Ganguly ◽  
T. Ikeda ◽  
K. Saitoh ◽  
M. Kondo ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Silicon Germanium ◽  
Hydrogenated Amorphous Silicon ◽  
Reaction Scheme ◽  
In Situ Monitoring ◽  
Alloy Films ◽  
Surface Hydrogen ◽  
Infrared Reflection ◽  
Amorphous Silicon Germanium ◽  
Hydrogenated Amorphous

ABSTRACTThe bonded hydrogen on the growing surface of hydrogenated amorphous silicon germanium (a-SiGe:H) alloy films has been investigated by use of infrared reflection absorption spectroscopy (IR-RAS). When the alloy films are Si-rich, the surface hydrogen bonded to Si atoms is found to behave in a similar way to those on the hydrogenated amorphous silicon (a-Si:H) films. This means that the thermal desorption stability of surface Si hydride species is not significantly affected by the coexistence of a small amount (typically 20 at.%) of Ge. On the contrary, the desorption behavior of surface hydrogen depends on the alloy composition when the a-SiGe:H films are Ge-rich. A surface reaction scheme is provided in an attempt to explain this series of behavior in surface hydrogen on the a-SiGe:H films.

Surface Processes during Growth of Hydrogenated Amorphous Silicon

2004 ◽  
Vol 808 ◽  
Author(s):  
Eray S. Aydil ◽  
Sumit Agarwal ◽  
Mayur Valipa ◽  
Saravanapriyan Sriraman ◽  
Dimitrios Maroudas
Keyword(s):  
Amorphous Silicon ◽  
Film Growth ◽  
Silicon Film ◽  
Hydrogenated Amorphous Silicon ◽  
Surface Processes ◽  
Atomistic Simulations ◽  
Elementary Surface ◽  
Hydrogenated Amorphous ◽  
And Diffusion

ABSTRACTHydrogenated amorphous silicon films for photovoltaics and thin film transistors are deposited from silane containing discharges. The radicals generated in the plasma such as SiH3 and H impinge on the surface and lead to silicon film growth through a complex network of elementary surface processes that include adsorption, abstraction, insertion and diffusion of various radicals. Mechanism and kinetics of these reactions determine the film composition and quality. Developing deposition strategies for improving the film quality requires a fundamental understanding of the radical-surface interaction mechanisms. We have been using in situ multiple total internal reflection Fourier transform infrared spectroscopy and in situ spectroscopic ellipsometry in conjunction with atomistic simulations to determine the elementary surface reaction and diffusion mechanisms. Synergistic use of experiments and atomistic simulations elucidate elementary processes occurring on the surface. Herein, we review our current understanding of the reaction mechanisms that lead to a-Si:H film growth with special emphasis on the reactions of the SiH3 radical.

Molecular-Dynamics Simulations of Hydrogenated Amorphous Silicon Thin-Film Growth

1995 ◽  
Vol 408 ◽  
Author(s):  
T. Ohira ◽  
O. Ukai ◽  
M. Noda ◽  
Y. Takeuchi ◽  
M. Murata ◽  
...  
Keyword(s):  
Thin Film ◽  
Molecular Dynamics ◽  
Amorphous Silicon ◽  
Film Growth ◽  
Hydrogenated Amorphous Silicon ◽  
Md Simulations ◽  
Thin Film Growth ◽  
Silicon Thin Film ◽  
Radical Migration ◽  
Hydrogenated Amorphous

AbstractWe have performed molecular-dynamics (MD) simulations of hydrogenated amorphous silicon (a-Si:H) thin-film growth using realistic many-body semiclassical potentials developed to describe Si-H interactions. In our MD model, it was assumed that SiH3, SiH2 and the H radicals are main precursors for the thin-film growth. In MD simulations of a-Si:H thin-film growth by many significant precursor SiH3 radicals, we have evaluated average radical migration distances, defect ratios, hydrogen contents, and film growth rates as a function of different incident radical energies to know the effect of the radical energization on the properties. As a result of the comparison between the numerical and experimental results, it was observed that the agreement is fairly good, and that an increase of radical migration distance due to the radical energization is effective on a- Si:H thin-film growth with a low defect.

In situelectron-spin-resonance measurements of film growth of hydrogenated amorphous silicon

1997 ◽  
Vol 70 (9) ◽  
pp. 1137-1139 ◽  
Author(s):  
Satoshi Yamasaki ◽  
Takahide Umeda ◽  
Junichi Isoya ◽  
Kazunobu Tanaka
Keyword(s):  
Amorphous Silicon ◽  
Film Growth ◽  
Hydrogenated Amorphous Silicon ◽  
Spin Resonance ◽  
Hydrogenated Amorphous
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