Dependence of H Diffusion in Hydrogenated Silicon on Doping and the Fermi Level

2000 ◽  
Vol 609 ◽  
Author(s):  
Wolfhard Beyer ◽  
Uwe Zastrow
Keyword(s):  
Hydrogen Diffusion ◽  
Secondary Ion Mass Spectrometry ◽  
Depth Profiling ◽  
Neutral Hydrogen ◽  
Diffusion Path ◽  
Strong Increase ◽  
Band Model ◽  
Hydrogenated Silicon ◽  
As Doping ◽  
Hydrogen Implantation

ABSTRACTFor three types of hydrogenated silicon films, amorphous, microcrystalline and crystalline hydrogenated silicon, hydrogen diffusion was studied as a function of doping level employing depth profiling by secondary ion mass spectrometry. Hydrogen implantation was used to control the hydrogen concentration. All three materials show a similar doping dependence of H diffusion, namely a strong increase upon boron (p-type) doping and a much lesser increase for n- type (P, As) doping. In a band model of H diffusion, the effect is related to a decrease in energy of the hydrogen diffusion path. Possible explanations are a different charge state of diffusing hydrogen or an effect of the Fermi energy on the release energy of neutral hydrogen.

Concentration Dependence of Hydrogen Diffusion in Hydrogenated Silicon

1998 ◽  
Vol 507 ◽  
Author(s):  
W. Beyer ◽  
U. Zastrow
Keyword(s):  
Diffusion Coefficient ◽  
Amorphous Silicon ◽  
Concentration Dependence ◽  
Hydrogen Concentration ◽  
Hydrogen Diffusion ◽  
Band Model ◽  
Hydrogenated Silicon ◽  
Trapping Model ◽  
Hydrogen Implantation ◽  
Amorphous Si

ABSTRACTThe concentration dependence of hydrogen diffusion was studied in hydrogenated crystalline and amorphous silicon prepared by hydrogen implantation into crystalline Si wafers and into amorphous silicon of low hydrogen concentration. The results are compared with data for plasma-grown a-Si:H and µc-Si:H films. The increase of the diffusion coefficient with rising hydrogen concentration in a-Si:H is explained by an (equilibrium) energy band model of hydrogen diffusion whereas the decrease of the diffusion coefficient in c-Si:H is explained by a trapping model. The different behavior is attributed to a greater flexibility of the amorphous Si network compared to the crystalline Si lattice which is also visible in a difference in hydrogen-related microstructure formation.

Atomic force microscopy (AFM) of the topography of silicon surfaces exposed to ion beams

1992 ◽  
Vol 50 (2) ◽  
pp. 1132-1133
Author(s):  
Mark Denker ◽  
Jennifer Wall ◽  
Mark Ray ◽  
Richard Linton
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Incidence Angle ◽  
Ion Beam ◽  
Depth Profiling ◽  
Depth Resolution ◽  
Ion Beams ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Trace Impurities ◽  
Energy Dose

Reactive ion beams such as O2+ and Cs+ are used in Secondary Ion Mass Spectrometry (SIMS) to analyze solids for trace impurities. Primary beam properties such as energy, dose, and incidence angle can be systematically varied to optimize depth resolution versus sensitivity tradeoffs for a given SIMS depth profiling application. However, it is generally observed that the sputtering process causes surface roughening, typically represented by nanometer-sized features such as cones, pits, pyramids, and ripples. A roughened surface will degrade the depth resolution of the SIMS data. The purpose of this study is to examine the relationship of the roughness of the surface to the primary ion beam energy, dose, and incidence angle. AFM offers the ability to quantitatively probe this surface roughness. For the initial investigations, the sample chosen was <100> silicon, and the ion beam was O2+.Work to date by other researchers typically employed Scanning Tunneling Microscopy (STM) to probe the surface topography.

Boron neutralization and hydrogen diffusion in silicon subjected to low-energy hydrogen implantation

1989 ◽  
Vol 48 (1) ◽  
pp. 31-40 ◽  
Author(s):  
T. Zundel ◽  
A. Mesli ◽  
J. C. Muller ◽  
P. Siffert
Keyword(s):  
Hydrogen Diffusion ◽  
Low Energy ◽  
Hydrogen Implantation

scholarly journals Antagonist effects of grain boundaries between the trapping process and the fast diffusion path in nickel bicrystals

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. Li ◽  
A. Hallil ◽  
A. Metsue ◽  
A. Oudriss ◽  
J. Bouhattate ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Hydrogen Diffusion ◽  
Short Circuit ◽  
Diffusion Path ◽  
Fast Diffusion ◽  
Fundamental Parameters ◽  
Segregation Energy ◽  
Atomistic Calculations ◽  
And Migration ◽  
Trapping Process

AbstractHydrogen-grain-boundaries interactions and their role in intergranular fracture are well accepted as one of the key features in understanding hydrogen embrittlement in a large variety of common engineer situations. These interactions implicate some fundamental processes classified as segregation, trapping and diffusion of the solute which can be studied as a function of grain boundary configuration. In the present study, we carried out an extensive analysis of four grain-boundaries based on the complementary of atomistic calculations and experimental data. We demonstrate that elastic deformation has an important contribution on the segregation energy which cannot be simply reduced to a volume change and need to consider the deviatoric part of strain. Additionally, some significant configurations of the segregation energy depend on the long-range elastic distortion and allows to rationalize the elastic contribution in three terms. By investigating the different energy barriers involved to reach all the segregation sites, the antagonist impact of grain boundaries on hydrogen diffusion and trapping process was elucidated. The segregation energy and migration energy are two fundamental parameters in order to classify the grain-boundaries as a trapping location or short circuit for diffusion.

Sign in / Sign up

Export Citation Format

Share Document