Optical Properties and Structure of Microcrystalline Silicon

1992 ◽  
Vol 258 ◽  
Author(s):  
Hien V. Nguyen ◽  
Ilsin An ◽  
Youming Li ◽  
C.R. Wronski ◽  
R.W. Collins
Keyword(s):  
Optical Properties ◽  
Vapor Deposition ◽  
Geometric Model ◽  
Chemical Vapor ◽  
Mean Free Path ◽  
Microcrystalline Silicon ◽  
Dominant Effect ◽  
Si Films ◽  
Electron Mean Free Path ◽  
Classical Size

ABSTRACTThe optical properties of thin film microcrystalline silicon (μc-Si:H) prepared by plasma-enhanced chemical vapor deposition (PECVD) have been studied by real time spectroscopie ellipsometry in the nucleation regime as isolated crystalline particles increase in size. A simple geometric model of nucleation allows us to remove the dominant effect of voids and extract the dielectric functions of the crystallites themselves. We find that the results can be understood in terms of a classical size effect whereby limitations on the electron mean free path by scattering at crystallite surfaces control the absorption onset from 2.0 to 3.0 eV. Finally, we describe how well-ordered, continuous 15 Å c-Si films can be prepared on metal substrates.

Influence of Power on the Microstructure and Optical Properties of Microcrystalline Si Films

2014 ◽  
Vol 1016 ◽  
pp. 305-308
Author(s):  
Hua Cheng ◽  
Feng Jiang ◽  
Chang Zheng Ma ◽  
Kuo Jiang
Keyword(s):  
Optical Properties ◽  
Vapor Deposition ◽  
Cyclotron Resonance ◽  
Electron Cyclotron Resonance ◽  
Gaseous Mixture ◽  
Chemical Vapor ◽  
Silicon Films ◽  
Microcrystalline Silicon ◽  
Si Films ◽  
Resonance Plasma

Microcrystalline silicon films were deposited using Ar diluted SiH4 gaseous mixture by electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR-PECVD). The effects of power on microstrcture and optical properties of microcrystalline silicon films were investigated. The results show that, with the increasing of the power, the crystallinity increased, but the concentration of hydrogen decreased monotonously. Furthermore, the absorption coefficient of the films increased monotonously, and the optical bandgap changed from 1.89eV to 1.75eV with the microwave power ranging from 400 W to 650W.

Large grain polycrystalline silicon via chemical vapor deposition

1999 ◽  
Vol 14 (3) ◽  
pp. 672-681 ◽  
Author(s):  
Bruce N. Beckloff ◽  
W. Jack Lackey ◽  
Elliott M. Pickering
Keyword(s):  
Grain Size ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Film Growth ◽  
Chemical Vapor ◽  
Process Variable ◽  
Dominant Effect ◽  
System A ◽  
B Doping ◽  
Si Films

Large grain polycrystalline Si films were grown by chemical vapor deposition (CVD) onto TiB2 substrates using the SiCl4–H2 reagent system. A statistically designed processing study was used to correlate the film growth rate, crystallographic orientation, and grain size with deposition temperature, the SiCl4 : H2 ratio, and the level of B doping. Each process variable influenced grain size with temperature having the dominant effect. Grains as large as 15 to 20 μm were achieved for a coating thickness of about 50 μm.

Optical Properties of Nanocrystalline Silicon Films with Different Deposition Temperatures

1999 ◽  
Vol 581 ◽  
Author(s):  
A. M. Ali ◽  
T. Inokuma ◽  
Y. Kurata ◽  
S. Hasegawa
Keyword(s):  
Optical Properties ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Nanocrystalline Silicon ◽  
Absorption Bands ◽  
Si Substrates ◽  
Fused Quartz ◽  
Si Films ◽  
Infrared Absorption Bands

AbsrtactNanocrystalline silicon (nc-Si) films were deposited on fused quartz and single (100) crystal Si substrates by plasma-enhanced chemical vapor deposition from a SiH4-H2 mixture at various deposition temperatures, Tδ. The effects of plasma-assisted hydrogenation at 300°C on the optical and structural properties were examined for the nc-Si films. The film deposited at Tδ = 730°C exhibits photoluminescence (PL) in its as-deposited state, but the intensity of PL decreases after hydrogenation. We find that a correlation between the PL intensity and infrared absorption bands at around 850 and 1000 cm−1.

Preparation and Optical Properties of Ultrathin Silicon Films

1994 ◽  
Vol 358 ◽  
Author(s):  
R. W. Collins ◽  
Hien V. Nguyen ◽  
Ilsin An ◽  
Yiwei Lu ◽  
M. Wakagi
Keyword(s):  
Vapor Deposition ◽  
Atomic Hydrogen ◽  
Quantum Confinement ◽  
Cluster Size ◽  
Crystalline Silicon ◽  
Chemical Vapor ◽  
Mean Free Path ◽  
Hydrogen Etching ◽  
Electron Mean Free Path

ABSTRACTUltrathin crystalline silicon (c-Si) and amorphous silicon (a-Si:H) films have been prepared using plasma-enhanced chemical vapor deposition (PECVD) and atomic hydrogen etching methods. The complex dielectric functions (2 < hv < 4.5 eV) of films consisting of isolated clusters have been measured in situ and in real time using spectroscopic ellipsometry. For 12 Å c-Si cluster films, a sharp absorption onset is observed near 3 eV that blue-shifts with decreasing thickness, in consistency with the quantum confinement of electrons. A much broader absorption onset, observed for ∼13 Å a-Si:H cluster films near 2 eV, is attributed to an electron mean free path that is less than the cluster size, which limits the appearance of confinement effects.

Deposition and Properties of Hydrogenated Microcrystalline Silicon (μc-Si:H) Films for Solar Cells

2013 ◽  
Vol 662 ◽  
pp. 173-176
Author(s):  
Yan Long Li ◽  
Zhong Lin Zhang ◽  
Hong Gang ◽  
Peng Qiu
Keyword(s):  
Optical Properties ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Glass Substrate ◽  
Chemical Vapor ◽  
Hot Wire ◽  
Microcrystalline Silicon ◽  
Electrical And Optical Properties ◽  
Wide Range ◽  
Deposited Films

Radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) technique is widely used in preparing uniform and large area a-Si:H films for various photoelectric devices. However, in the deposition processes of PECVD, the plasma bombardment to the deposited films will result in hindering the processes of crystallization. In the processes of hot-wire chemical vapor deposition (HWCVD), high-crystallinity films with a quickly growth rate can be obtained. In this article, hydrogenated microcrystalline silicon (μc-Si:H) films on glass substrate were prepared by a combination technique of HWCVD and RF inductively coupled plasma (ICP) at a low pressure (7Pa). The deposition parameters including the distance between the glass substrate with the hot wire and the flow ratio of SiH4/H2 in order to optimize the properties of μc-Si:H films. The crystallinity, microstructure, electrical and optical properties of the μc-Si:H films were investigated by Raman Spectroscopy, X-ray diffraction analysis (XRD), and UV-visible spectrometer, respectively. The results indicate that the crystallinity of the μc-Si:H films can be controlled at a very wide range and the deposition rate is up to 3nm/s. The deposited films show excellence electrical and optical properties.

Physical Properties of Undoped and Doped Microcrystalline SiC:H Deposited by PECVD

1991 ◽  
Vol 219 ◽  
Author(s):  
F. Demichelis ◽  
C. F. Pirri ◽  
E. Tresso ◽  
G. Dellamea ◽  
V. Rigato ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Optical Properties ◽  
Electrical Properties ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Systematic Investigation ◽  
Optical And Electrical Properties ◽  
Microcrystalline Silicon ◽  
Window Material

ABSTRACTExperimental results on a systematic investigation on the elemental composition, structural, optical and electrical properties of undoped and doped microcrystalline silicon carbide films deposited by Plasma Enhanced Chemical Vapor Deposition.The doped samples show high values of dark conductivity accompanied by good optical properties so to satisfy the requirements for heterojunction window material.

Growth Mechanism of Microcrystalline Silicon Deposited by ECRCVD

1996 ◽  
Vol 452 ◽  
Author(s):  
I. Beckers ◽  
E. Conrad ◽  
P. Müller ◽  
N. H. Nickel ◽  
I. Sieber ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Cyclotron Resonance ◽  
Electron Cyclotron Resonance ◽  
Chemical Vapor ◽  
Growth Mechanisms ◽  
Microcrystalline Silicon ◽  
Crystalline Fraction ◽  
Hydrogen Dilution ◽  
Si Films ◽  
Scanning Electron

AbstractMicrocrystalline silicon (μc-Si) films were prepared by electron cyclotron resonance assisted chemical vapor deposition (ECRCVD) using helium, argon and hydrogen dilution. The crystalline fraction was estimated from Raman backscattering spectra and scanning electron-microscopy (SEM) was used to obtain information on roughness and homogeneity of the films. For hydrogen dilution the highest crystallinity (Xc = 85 %) occurs at a ratio of ΔH = [H2]/([H2]+[SiH4])= 0.98. At the same time the deposition rate decreases continuously with increasing H2 dilution. These results are consistent with the idea that H etching promotes the growth of μc-Si. At ΔH > 0.98 a Xc decreases due to a H mediated transition of small crystallites into amorphous tissue. The implications of these results for the growth mechanisms are discussed.

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