High Quality Amorphous Silicon Prepared by Catalytic Chemical Vapor Deposition (CTL-CVD) Method

1987 ◽  
Vol 95 ◽  
Author(s):  
Hideki Matsumura
Keyword(s):  
Amorphous Silicon ◽  
Vapor Deposition ◽  
Optical Band Gap ◽  
Chemical Vapor ◽  
Catalytic Reactions ◽  
Gas Mixture ◽  
High Quality ◽  
Phosphorus Doping ◽  
Cvd Method ◽  
Hydrogenated Amorphous

AbstractA new method of producing high quality hydrogenated amorphous silicon (a-Si:H) and its compound films is presented. An SiH4 and H2 gas mixture is decomposed without using any plasmas or photochemical excitation, but using only thermal and catalytic reactions between deposition gas and a heated tungsten catalyzer. Photoconductivity of a-Si:H films produced by, this method reaches 10−3 (Ωcm)−1 and photosensitivity exceeds 105 for illumination of AM-1 light of 100 mW/cm2, highly efficient boron- or phosphorus-doping into the films is achieved, and also the optical band gap of the films is easily controlled without apparent degradation of the properties by adding GeH4 gas to the deposition gas.

Amorphous Silicon—Germanium Deposited by Photo—CVD

1985 ◽  
Vol 49 ◽  
Author(s):  
H. Itozaki ◽  
N. Fujita ◽  
H. Hitotsuyanagi
Keyword(s):  
Solar Cell ◽  
Amorphous Silicon ◽  
Vapor Deposition ◽  
Silicon Germanium ◽  
Chemical Vapor ◽  
High Quality ◽  
Transmission Electron ◽  
Amorphous Silicon Germanium ◽  
Hydrogenated Amorphous ◽  
Gas Ratio

AbstractHydrogenated amorphous silicon germanium (a—SiGe:H) films were deposited by photo—chemical vapor deposition (Photo—CVD) of SiH4 and GeH4 with mercury sensitizer. Their band gap was controlled from 0.9 eV to 1.9 eV by changing the gas ratio of SiH4 and GeH4. High quality opto—electrical properties have been obtained for thea—SiGe:H films by Photo—CVD. Hydrogen termination and microstructure of a-SiGe:H were investigated by infrared absorption and transmission electron microscopy. Ana—Si:H solar cell and an a—Si:H/a—SiGe:H stacked solar cell were made, each of which has conversion efficiency 5.3% and 5.1%, respectively.

scholarly journals Graphene Trails on PECVD Hydrogenated Amorphous Silicon Carbide Films SiC-a: H by Laser Writing at Room Temperature

2020 ◽  
Vol 15 (2) ◽  
pp. 1-4
Author(s):  
Deissy Johanna Feria ◽  
Marcelo Carreño ◽  
Ricardo Rangel ◽  
Ines Pereyra
Keyword(s):  
Silicon Carbide ◽  
Chemical Vapor Deposition ◽  
Amorphous Silicon ◽  
Vapor Deposition ◽  
Room Temperature ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapor ◽  
High Quality ◽  
Amorphous Silicon Carbide ◽  
Hydrogenated Amorphous

The production of high quality graphene without the need for catalyst metals as in the case of chemical vapor deposition (CVD) techniques remain a challenge. Silicon carbide is one of the materials with potential to form graphene films on its surface through thermal decomposition when subjected to high temperatures and ultrahigh vacuum. This technique is highly desirable since it enables the elimination of corrosion and transfer steps, which can leave residues in the graphene structure and alter its quality, as well as its electrical proprieties, however it is a costly and time consuming method. In this work, we present the production of graphene trails by direct laser radiation writing at room temperature and atmospheric pressure on hydrogenated amorphous silicon carbide films (SiC-a:H) produced by Plasma Enhanced Chemical Vapor Deposition (PECVD).  Graphene trails of approximately 1cm x 4μm were obtained with patterns designed by computer Aided Design (CAD) software. Variations were made in both scanning speed and laser focal length, identifying a great dependence on the graphene quality with these two parameters. The best results of the Raman Spectroscopy Mappings showed high quality graphene with distance between point defects (LD) of 20nm, crystallite size (La) of 25nm and few layers (2-3). In addition, the electrical measurements from Au/Ti (20nm/100nm) electrodes deposited by electron beam evaporation showed high conductivity, with sheet resistances (Rs) from 0.7kΩ to 1.3 kΩ per square. This technique opens a great possibility of manufacturing devices for applications in electronics, being a fast, efficient and low cost method.

High Rate Deposition of Stable Hydrogenated Amorphous Silicon in Transition from Amorphous to Microcrystalline Silicon

2003 ◽  
Vol 762 ◽  
Author(s):  
Guofu Hou ◽  
Xinhua Geng ◽  
Xiaodan Zhang ◽  
Ying Zhao ◽  
Junming Xue ◽  
...  
Keyword(s):  
Phase Transition ◽  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapor ◽  
High Rate ◽  
Very High Frequency ◽  
High Quality ◽  
Working Pressure ◽  
Hydrogen Dilution ◽  
Hydrogenated Amorphous

AbstractHigh rate deposition of high quality and stable hydrogenated amorphous silicon (a-Si:H) films were performed near the threshold of amorphous to microcrystalline phase transition using a very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) method. The effect of hydrogen dilution on optic-electronic and structural properties of these films was investigated by Fourier-transform infrared (FTIR) spectroscopy, Raman scattering and constant photocurrent method (CPM). Experiment showed that although the phase transition was much influenced by hydrogen dilution, it also strongly depended on substrate temperature, working pressure and plasma power. With optimized condition high quality and high stable a-Si:H films, which exhibit σph/σd of 4.4×106 and deposition rate of 28.8Å/s, have been obtained.

Light-Induced Effects on Fluorinated Amorphous and Microcrystalline Silicon Films

1996 ◽  
Vol 420 ◽  
Author(s):  
Hong-Seok Choi ◽  
Keun-Ho Jang ◽  
Jhun-Suk Yoo ◽  
Min-Koo Han
Keyword(s):  
Band Gap ◽  
Vapor Deposition ◽  
Optical Band Gap ◽  
Silicon Film ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapor ◽  
Rf Plasma ◽  
Microcrystalline Silicon ◽  
Amorphous Silicon Film ◽  
Hydrogenated Amorphous

AbstractThe fluorinated amorphous and microcrystalline silicon (a,μc-Si:H;F) films have been prepared by rf plasma enhanced chemical vapor deposition (PECVD) with SiH 4 and SiF 4 gas mixtures. The stretching Si-O (1085 cm-1) and SiH2 (2100 cm-1) bands estimated from infrared (IR) spectroscope data have related to the evolution of crystallinity and the optical band gap was shifted by introducing Si-O bonds. The sub-band gap absorption coefficient in a,μc-Si:H;F films was about one order lower than that in hydrogenated amorphous silicon film (a-Si:H). The subband gap absorption in a-Si:H;F film was comparable to that in tic-Si:H;F films. The lightinduced degradation of a,μc-Si:H;F films were also suppressed.

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