Separation of Nucleation and Growth Processes of Nanocrystalline Silicon by Hydrogen Radical Treatment of Hydrogenated Amorphous Silicon

1992 ◽  
Vol 283 ◽  
Author(s):  
Masanori Otobe ◽  
Shunri Oda
Keyword(s):  
Amorphous Silicon ◽  
Hydrogen Diffusion ◽  
Hydrogenated Amorphous Silicon ◽  
Nanocrystalline Silicon ◽  
Nucleation And Growth ◽  
Growth Processes ◽  
Plan View ◽  
Hydrogen Radical ◽  
Hydrogen Radicals ◽  
Hydrogenated Amorphous

ABSTRACTWe have investigated nucleation and growth mechanism of nanocrystalline silicon (nc-Si) based on the experimental observation of plan-view transmission electron microscopy. Nanocrystalline Si has been prepared by hydrogen radical annealing of hydrogenated amorphous silicon (a-Si:H) layer, which is deposited on hydrogen radical treated a-Si:H buffer layer. Nanocrystallization depends critically upon hydrogen radical annealing time and the thickness ofa-Si:H layer. Hydrogen radicals play important roles in both nucleation and growth processes in a different way. Growth of nc-Si can be explained by “hydrogen diffusion model”, in which hydrogen radicals diffusing through a-Si:H layer to interface cause nanocrystallization. Our results imply that nuclei for nc-Si are generated at the interface between a-Si:H and under layer when treated by hydrogen radicals.

Hydrogenated Nanocrystalline Silicon Thin Film Transistor Array for X-ray Detector Application

2008 ◽  
Vol 1066 ◽  
Author(s):  
Kyung-Wook Shin ◽  
Mohammad R. Esmaeili-Rad ◽  
Andrei Sazonov ◽  
Arokia Nathan
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Threshold Voltage ◽  
Hydrogenated Amorphous Silicon ◽  
Nanocrystalline Silicon ◽  
Amorphous Selenium ◽  
Breakdown Field ◽  
Storage Capacitor ◽  
X Ray ◽  
Hydrogenated Amorphous

ABSTRACTHydrogenated nanocrystalline silicon (nc-Si:H) has strong potential to replace the hydrogenated amorphous silicon (a-Si:H) in thin film transistors (TFTs) due to its compatibility with the current industrial a-Si:H processes, and its better threshold voltage stability [1]. In this paper, we present an experimental TFT array backplane for direct conversion X-ray detector, using inverted staggered bottom gate nc-Si:H TFT as switching element. The TFTs employed a nc-Si:H/a-Si:H bilayer as the channel layer and hydrogenated amorphous silicon nitride (a-SiNx) as the gate dielectric; both layers deposited by plasma enhanced chemical vapor deposition (PECVD) at 280°C. Each pixel consists of a switching TFT, a charge storage capacitor (Cpx), and a mushroom electrode which serves as the bottom contact for X-ray detector such as amorphous selenium photoconductor. The chemical composition of the a-SiNx was studied by Fourier transform infrared spectroscopy. Current-voltage measurements of the a-SiNx film demonstrate that a breakdown field of 4.3 MV/cm.. TFTs in the array exhibits a field effect mobility (μEF) of 0.15 cm2/V·s, a threshold voltage (VTh) of 5.71 V, and a subthreshold leakage current (Isub) of 10−10 A. The fabrication sequence and TFT characteristics will be discussed in details.

Role of Hydrogen Microstructure in Amorphous Silicon

1992 ◽  
Vol 258 ◽  
Author(s):  
Sufi Zafar ◽  
E. A. Schiff
Keyword(s):  
Amorphous Silicon ◽  
Hydrogen Evolution ◽  
Hydrogen Diffusion ◽  
Hydrogenated Amorphous Silicon ◽  
Hydrogenated Amorphous ◽  
Unified Description

ABSTRACTA model for correlating the observed properties of hydrogenated amorphous silicon (a-Si:H) with the underlying hydrogen microstructure is reviewed. The model provides a unified description of defect equilibration, hydrogen evolution, rehydrogenation and hydrogen diffusion measurements.

scholarly journals Plasma-deposited hydrogenated amorphous silicon films: multiscale modelling reveals key processes

RSC Advances ◽  
2017 ◽  
Vol 7 (31) ◽  
pp. 19189-19196 ◽  
Author(s):  
Z. Marvi ◽  
S. Xu ◽  
G. Foroutan ◽  
K. Ostrikov ◽  
I. Levchenko
Keyword(s):  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Film Structure ◽  
Multiscale Modelling ◽  
Structure And Properties ◽  
Growth Processes ◽  
Chemical Mechanisms ◽  
Physical And Chemical ◽  
Hydrogenated Amorphous

Physical and chemical mechanisms and role of plasma in the synthesis of hydrogenated amorphous silicon were studied numerically to reveal the key growth processes and, hence, to ensure a higher level of control over the film structure and properties.

Hydrogen Diffusion in Boron-Doped Hydrogenated Amorphous Silicon Films: Crystallization and Induced Structural Changes

2005 ◽  
Vol 864 ◽  
Author(s):  
F. Kail ◽  
A. Hadjadj ◽  
P. Roca i Cabarrocas
Keyword(s):  
Amorphous Silicon ◽  
Structural Changes ◽  
Hydrogen Diffusion ◽  
Hydrogen Plasma ◽  
Hydrogenated Amorphous Silicon ◽  
Silicon Films ◽  
Hydrogen Atoms ◽  
Boron Doped ◽  
Hydrogenated Amorphous ◽  
Positively Charged

AbstractWe have studied the evolution of the structure of boron-doped hydrogenated amorphous silicon films exposed to a hydrogen plasma. From the early stages of exposure, hydrogen diffuses and forms a thick H-rich subsurface. At longer times, hydrogen plasma leads to the formation of a microcrystalline layer via chemical transport without crystallization of the initial layer. We observe that the hydrogen content increases in the films during a plasma exposure and once the microcrystalline layer is formed hydrogen diffuses out of the sample accompanied with a decrease in the boron content. This effect can be attributed to the electric field developed within the heterojunction a-Si:H/μc-Si:H that drives the positively charged hydrogen atoms in the boron-doped layer towards the μc-Si:H layer.

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