The Role of Hydrogen in Laser Crystallized Polycrystalline Silicon

2002 ◽  
Vol 744 ◽  
Author(s):  
N. H. Nickel ◽  
K. Brendel
Keyword(s):  
Polycrystalline Silicon ◽  
Hydrogen Diffusion ◽  
Laser Crystallization ◽  
Hydrogen Binding ◽  
Amorphous Precursor ◽  
Pronounced Increase ◽  
Precursor Material ◽  
Residual Hydrogen ◽  
Hydrogenated Amorphous

ABSTRACTPolycrystalline silicon produced by laser crystallization of hydrogenated amorphous silicon contains large amounts of residual hydrogen. This reservoir of hydrogen can be used to passivate additional grain boundary defects by annealing the specimens at low temperatures in vacuum. Information on hydrogen bonding is obtained from hydrogen diffusion measurements. Laser crystallization results in a pronounced increase of the hydrogen binding energy in the resulting poly-Si samples compared to the amorphous precursor material. Fully crystallized poly-Si contains H concentrations of up to 17 at.%.

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.

Silicon-Hydrogen Bonds in Boron and Phosphorous Doped Polycrystalline Silicon Thin Films

2004 ◽  
Vol 808 ◽  
Author(s):  
R. Saleh ◽  
N. H. Nickel
Keyword(s):  
Binding Energy ◽  
Polycrystalline Silicon ◽  
Binding Energies ◽  
Vibration Modes ◽  
Laser Crystallization ◽  
Hydrogen Binding ◽  
Local Vibration ◽  
Silicon Thin Films ◽  
The One ◽  
Hydrogen Effusion

ABSTRACTHydrogen bonding in laser crystallized boron and phosphorous doped polycrystalline silicon is investigated using Raman spectroscopy and hydrogen effusion measurements. During laser crystallization the intensity of the local vibration modes near 2000 and 2100 cm−1 decreases. The intensity of vibration mode at 2000 cm−1 decreases faster than the one at 2100 cm−1. From H effusion measurements, the hydrogen density-of-states (H DOS) distribution is derived. For undoped amorphous silicon the H DOS exhibits two prominent peaks at hydrogen binding energies of E– μH = –1.1 and –1.5 eV. In B doped a-Si:H the peak at –1.1 eV is less pronounced while in P doped a-Si:H the H binding energy increases by about 0.1 eV. In all samples laser crystallization causes an increase of the H binding energy by about 0.2 – 0.3 eV. However, the peaks in the H DOS observed in B-doped samples are preserved during laser crystallization.

Hydrogen Diffusion and Thermal Equilibrium of Electronic States in a-Si:H

1987 ◽  
Vol 95 ◽  
Author(s):  
R. A. Street
Keyword(s):  
Thermal Equilibrium ◽  
Hydrogen Diffusion ◽  
Electronic States ◽  
Thermally Induced ◽  
Rate Limiting Step ◽  
Induced Changes ◽  
Rate Limiting ◽  
Hydrogenated Amorphous ◽  
Diffusion Of Hydrogen

AbstractThis paper reviews the recent evidence for thermal equilibrium effects in the electronic behavior of hydrogenated amorphous silicon, and relates the thermally induced changes to the motion of bonded hydrogen. The electronic properties are studied through measurements of d.c conductivity and-.weep out, and the role of hydrogen is explored through its diffusion. The magnitude and doping dependence of the diffusion coefficient DH matches the data on the equilibration of the electronic states. Furthermore both the diffusibn and the relaxation can be described by the same dispersive time dependence. It is argued that the diffusion of hydrogen is the rate limiting step in the the equilibration mechanisms and determines the kinetics.

Structural relationships in the synthesis of cubic boron nitride thin films by ion-assisted deposition

1994 ◽  
Vol 52 ◽  
pp. 638-639
Author(s):  
D. L. Medlin ◽  
T. A. Friedmann ◽  
P. B. Mirkarimi ◽  
M. J. Mills ◽  
K. F. McCarty
Keyword(s):  
Boron Nitride ◽  
Ion Irradiation ◽  
Cubic Boron Nitride ◽  
Film Stress ◽  
Bonded Phases ◽  
Structural Relationships ◽  
Precursor Material ◽  
Pressure Synthesis ◽  
Microstructure Of The Material

The allotropes of boron nitride include two sp2-bonded phases with hexagonal and rhombohedral structures (hBN and rBN) and two sp3-bonded phases with cubic (zincblende) and hexagonal (wurtzitic) structures (cBN and wBN) (Fig. 1). Although cBN is synthesized in bulk form by conversion of hBN at high temperatures and pressures, low-pressure synthesis of cBN as a thin film is more difficult and succeeds only when the growing film is simultaneously irradiated with a high flux of ions. Only sp2-bonded material, which generally has a disordered, turbostratic microstructure (tBN), will form in the absence of ion-irradiation. The mechanistic role of the irradiation is not well understood, but recent work suggests that ion-induced compressive film stress may induce the transformation to cBN.Typically, BN films are deposited at temperatures less than 1000°C, a regime for which the structure of the sp2-bonded precursor material dictates the phase and microstructure of the material that forms from conventional (bulk) high pressure treatment.

Role of atomic hydrogen diffusion in a hydrogen flame

2007 ◽  
Vol 43 (2) ◽  
pp. 125-131 ◽  
Author(s):  
V. A. Bunev ◽  
V. N. Panfilov ◽  
V. S. Babkin
Keyword(s):  
Atomic Hydrogen ◽  
Hydrogen Diffusion ◽  
Hydrogen Flame

Light-Induced Metastable Defects in a-Si:H: Towards an Understanding

1985 ◽  
Vol 49 ◽  
Author(s):  
Martin Stutzmann ◽  
Warren B. Jackson ◽  
Chuang Chuang Tsai
Keyword(s):  
Amorphous Silicon ◽  
Mechanical Stress ◽  
Hydrogenated Amorphous Silicon ◽  
Material Parameters ◽  
Kinetic Behaviour ◽  
Proposed Model ◽  
Special Cases ◽  
The Stability ◽  
Hydrogenated Amorphous

AbstractThe dependence of the creation and the annealing of metastable dangling bonds in hydrogenated amorphous silicon on various material parameters will be discussed in the context of a recently proposed model. After a brief review of the kinetic behaviour governing defect creation and annealing in undoped a- Si:H, a number of special cases will be analyzed: the influence of alloying with O, N, C, and Ge, changes introduced by doping and compensation, and the role of mechanical stress. Finally, possibilities to increase the stability of a-Si:H based devices will be examined.

The role of the blocking structure in hydrogenated amorphous silicon vidicon targets

1981 ◽  
Vol 52 (12) ◽  
pp. 7275-7280 ◽  
Author(s):  
Shunri Oda ◽  
Keishi Saito ◽  
Hisashi Tomita ◽  
Isamu Shimizu ◽  
Eiichi Inoue
Keyword(s):  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Hydrogenated Amorphous

Grain Enlargement of Polycrystalline Silicon by Multipulse Excimer Laser Annealing: Role of Hydrogen

2006 ◽  
Vol 45 (4A) ◽  
pp. 2726-2730 ◽  
Author(s):  
Naoya Kawamoto ◽  
Atsushi Masuda ◽  
Naoto Matsuo ◽  
Yasuhiro Seri ◽  
Toshimasa Nishimori ◽  
...  
Keyword(s):  
Excimer Laser ◽  
Polycrystalline Silicon ◽  
Laser Annealing ◽  
Excimer Laser Annealing
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