Plasma deposition of hydrogenated amorphous silicon: Effect of rf power

1989 ◽  
Vol 65 (2) ◽  
pp. 575-580 ◽  
Author(s):  
V. I. Kuznetsov ◽  
R. C. van Oort ◽  
J. W. Metselaar
Keyword(s):  
Amorphous Silicon ◽  
Plasma Deposition ◽  
Hydrogenated Amorphous Silicon ◽  
Rf Power ◽  
Hydrogenated Amorphous

Hydrogenated Amorphous Silicon Alloys Prepared by CVD of Higher Silanes

1986 ◽  
Vol 70 ◽  
Author(s):  
Masud Akhtar ◽  
Herbert A. Weaklie
Keyword(s):  
Amorphous Silicon ◽  
Band Gap ◽  
Plasma Deposition ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapor ◽  
Wide Band ◽  
Dark Conductivity ◽  
Attractive Alternative ◽  
Silicon Alloys ◽  
Hydrogenated Amorphous

ABSTRACTHydrogenated amorphous silicon may be deposited at relatively low temperatures, where the density of defects may be expected to be low, by the chemical vapor deposition (CVD) of higher silanes. This method is an attractive alternative to plasma deposition techniques. We describe here the preparation of a-Si:H and related alloys incorporating carbon, germanium, and fluorine. a-Si:H films were deposited on heated substrates in the range 365°C-445°C by CVD of Si2H6 and Si3H8. The optical gap (Eg) ranged from 1.4 to 1.7 eV and the properties of films deposited from either Si2 H6 or Si3 H8 were quite similar. Wide band gap (Eg=2 eV) alloys of a-SiC:H doped with boron were prepared by CVD of disilane, methyl silane, and diborane. We also prepared variable band gap a-SiC:H alloys by substituting F2C= CFH for methylsilane, and these films were found to have approximately 1–2% fluorine incorporated. The dark conductivity of the boron doped a-SiC:H alloys dep~sited from either carbon source ranged from ix10-7 to 6x10-7 (ohm-cm)-1. We also prepared low band aap alloys of Si and Ge by CVD of trisilane and germane. The band gap of a film containing 20% Ge was 1.5 eV; however, the photoconductivity of the film was relatively low.

Effect of Interface and Surface on the Performance of a-Si:H TFTs

1992 ◽  
Vol 258 ◽  
Author(s):  
Jin Jang ◽  
Moon Youn Jung ◽  
Sun Sung Yoo ◽  
Hyon Kyun Song ◽  
Jung Mok Jun
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Buffer Layer ◽  
Thin Film Transistors ◽  
Hydrogenated Amorphous Silicon ◽  
Surface Oxidation ◽  
Gate Insulator ◽  
Rf Power ◽  
Electron Accumulation ◽  
Hydrogenated Amorphous

ABSTRACTWe have studied the effects of interface and surface on the performance of hydrogenated amorphous silicon(a-Si:H) thin film transistors. The effects of rf power, the buffer layer between the gate insulator and a-Si:H, and the surface oxidation on the performance on the a-Si:H TFTs have been investigated. By introducing suitable buffer layer, we can increase the mobility up to 2.1 cm2/Vs. The surface oxidation gives rise to the electron accumulation near the surface.

Radio Frequency Power Dependence of Defect Density at Hydrogenated Amorphous Silicon Interface

1991 ◽  
Vol 237 ◽  
Author(s):  
Hisanori Ihara ◽  
Takeo Sakakubo ◽  
Hidetoshi Nozaki
Keyword(s):  
Radio Frequency ◽  
Amorphous Silicon ◽  
Buffer Layer ◽  
Defect Density ◽  
Hydrogenated Amorphous Silicon ◽  
Rf Power ◽  
Interface Defect ◽  
The Difference ◽  
Silicon Interface ◽  
Hydrogenated Amorphous

ABSTRACTA hydrogenated amorphous silicon (a-Si:H) interface fabrication technology for the plasma CVD method, which can produce low interface defect density, is presented. The relation between the interface defect density and radio frequency (RF) power was investigated. As a result, the difference between the interface defect density and the bulk defect density decreased with increasing the RF power. A high RF power (25 W) a-Si:H buffer layer 5 nm thick was deposited on the interface before depositing low RF power (5 W) a-Si:H layer with a low bulk defect density. It has been found that the ideal defect density distribution, which shows the uniform distribution with the very low defect density (4.2×1014 cm) from the i/i interface to the bulk, can be accomplished by 5 nm buffer layer.

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