Comment on ‘‘Mechanism of HF etching of silicon surfaces: A theoretical understanding of hydrogen passivation’’

1991 ◽  
Vol 66 (12) ◽  
pp. 1647-1647 ◽  
Author(s):  
E. Sacher ◽  
A. Yelon
Keyword(s):  
Silicon Surfaces ◽  
Hydrogen Passivation ◽  
Theoretical Understanding

Mechanism of HF etching of silicon surfaces: A theoretical understanding of hydrogen passivation

1990 ◽  
Vol 65 (4) ◽  
pp. 504-507 ◽  
Author(s):  
G. W. Trucks ◽  
Krishnan Raghavachari ◽  
G. S. Higashi ◽  
Y. J. Chabal
Keyword(s):  
Silicon Surfaces ◽  
Hydrogen Passivation ◽  
Theoretical Understanding

INFRARED SPECTROSCOPY OF H-TERMINATED SILICON SURFACES

1993 ◽  
Vol 07 (04) ◽  
pp. 1031-1078 ◽  
Author(s):  
Y.J. CHABAL ◽  
A.L. HARRIS ◽  
KRISHNAN RAGHAVACHARI ◽  
J.C. TULLY
Keyword(s):  
Infrared Spectroscopy ◽  
Vibrational Energy ◽  
Mass Difference ◽  
A Priori ◽  
Large Mass ◽  
Quantitative Information ◽  
Model Systems ◽  
Silicon Surfaces ◽  
Structural Description ◽  
Theoretical Understanding

In this review, the present level of infrared spectroscopy at surfaces is described by using hydrogen-terminated silicon surfaces as model systems. The electronic structure of the adsorbate, H, and the large mass difference between H and Si simplify the interpretation of the data and make it possible for the theories to give reliable quantitative information. In particular, ab initio cluster calculations provide an accurate structural description and precise vibrational frequencies for various surface configurations, and are used as the basis of a priori simulations of the line shape of H on silicon. A special emphasis is given to the recent discovery of chemical etching to prepare H-terminated silicon surfaces because it has greatly helped in understanding structural and dynamical properties of H-terminated silicon surfaces. In particular, both the energy and phase relaxation of the Si-H stretching vibration on the flat, ideally hydrogen terminated Si(111) surface have been measured directly and evidence for vibrational energy diffusion has been obtained on vicinal, H-terminated Si(111) surfaces. The data and current theoretical understanding of the chemically prepared Si(111) surfaces are presented and discussed.

Effect of Low Energy Hydrogen Implants on Damage Caused by Argon Ion Beam Etching

1983 ◽  
Vol 25 ◽  
Author(s):  
A. Climent ◽  
J.-S. Wang ◽  
S. J. Fonash
Keyword(s):  
Ion Beam ◽  
Ion Source ◽  
Low Energy ◽  
Silicon Surfaces ◽  
Hydrogen Passivation ◽  
Hydrogen Ions ◽  
Ion Beam Etching ◽  
Hydrogen Implantation ◽  
Argon Ions ◽  
Argon Ion

ABSTRACTThe dry etching technologies reactive ion etching (RIE) and ion beam etching (IBE) have both been shown to cause a damaged layer at silicon surfaces. It has been demonstrated that this damage can be annealed out or, alternatively, it can be passivated with low energy hydrogen implants from a Kaufman ion source. This study further explores the hydrogen passivation approach by focusing on the effect of hydrogen implantation on damage caused by argon ion beam etching. The lighter hydrogen ions are actually shown ta cause more extensive damage than the heavier argon ions. However, by using low-energy hydrogen implants all damage, that present from the Ar and that generated during the hydrogen implant, can be passivated.

Effects of Hydrogen Coverage on Silicon Surface Reactivity

1992 ◽  
Vol 259 ◽  
Author(s):  
A.C. Dillon ◽  
M.B. Robinson ◽  
S.M. George ◽  
P. Gupta
Keyword(s):  
Porous Silicon ◽  
Silicon Surface ◽  
High Surface ◽  
Surface Cleaning ◽  
Surface Reactivity ◽  
Silicon Surfaces ◽  
Initial Surface ◽  
Hydrogen Passivation ◽  
Surface Species ◽  
Oxidation Rates

ABSTRACTHydrogen passivation of silicon surfaces plays an important role in silicon surface cleaning and preparation. To measure the effect of hydrogen passivation on silicon surface reactivity, Fourier transform infrared (FTIR) transmission spectroscopy was used to monitor the oxidation of silicon surfaces versus hydrogen coverage. Experiments were performed insitu in an ultrahigh vacuum (UHV) chamber using high surface area poroussilicon samples. Si-H stretching and bending vibrations and Si-O-Si stretching vibrations were employed to monitor the silicon surface species. Oxidation studies with O2 conducted versus various initial hydrogen coverages revealed that oxidation rates and apparent oxygen saturation levels on porous silicon decreased as a function of initial surface hydrogen coverage. Exceptional surface stability was observed when the porous silicon surface was passivated by both monohydride and dihydride surface species. In addition, new blue-shifted Si-H stretching and bending features were observed following the oxidation of partially hydrogen-passivated porous silicon which indicated the presence of Ox SiH species. Thermal annealing studies revealed that the thermal stability of these OxSiH species increased with increasing oxidation of the silicon surface. These results have important implications for silicon growth and surface cleaning because they indicate that hydrogen removal is more difficult when the silicon surface is contaminated with oxygen. These FTIR results have also been compared with earlier results of oxidation versus hydrogen coverage on Si(111) 7×7.

Dissociated Σ=27 boundaries in silicon

1988 ◽  
Vol 46 ◽  
pp. 624-625
Author(s):  
A. Garg ◽  
W.A.T. Clark ◽  
J.P. Hirth
Keyword(s):  
Electron Diffraction ◽  
Local Minimum ◽  
Boundary Energy ◽  
Coincidence Site Lattice ◽  
Boundary Plane ◽  
Low Energy ◽  
Theoretical Understanding ◽  
Site Lattice ◽  
Kikuchi Pattern ◽  
Analysis Techniques

In the last twenty years, a significant amount of work has been done in the theoretical understanding of grain boundaries. The various proposed grain boundary models suggest the existence of coincidence site lattice (CSL) boundaries at specific misorientations where a periodic structure representing a local minimum of energy exists between the two crystals. In general, the boundary energy depends not only upon the density of CSL sites but also upon the boundary plane, so that different facets of the same boundary have different energy. Here we describe TEM observations of the dissociation of a Σ=27 boundary in silicon in order to reduce its surface energy and attain a low energy configuration.The boundary was identified as near CSL Σ=27 {255} having a misorientation of (38.7±0.2)°/[011] by standard Kikuchi pattern, electron diffraction and trace analysis techniques. Although the boundary appeared planar, in the TEM it was found to be dissociated in some regions into a Σ=3 {111} and a Σ=9 {122} boundary, as shown in Fig. 1.

Unlock imagined: arts in criminal justice

2019 ◽  
Vol 1 (2) ◽  
pp. 131-143
Author(s):  
Alison Frater
Keyword(s):  
Criminal Justice ◽  
Criminal Justice System ◽  
Justice System ◽  
Interdisciplinary Approach ◽  
Personal Perspective ◽  
Theoretical Understanding ◽  
The Arts ◽  
Optimistic Picture ◽  
The Uk ◽  
Causes Of Crime

Starting with a personal perspective this piece outlines the place and role of the arts in the criminal justice system in the UK. It paints an optimistic picture, though an unsettling one, because the imagination and reflexiveness of the arts reveals a great deal about the causes of crime and the consequences of incarceration. It raises questions about the transforming impact of the arts: how the benefits could, and should, be optimised and why evaluations of arts interventions are consistent in identifying the need for a non-coercive, more socially focused, paradigm for rehabilitation. It concludes that the deeper the arts are embedded in the criminal justice system the greater the benefits will be, that a more interdisciplinary approach would support better theoretical understanding, and that increased capacity to deliver arts in the criminal justice system is needed to offer more people a creative pathway out of crime.

INITIATIVE BUDGETING AS AN INSTRUMENT OF TERRITORIAL SELF-GOVERNMENT

2019 ◽  
Vol 86 (3) ◽  
pp. 77-90
Author(s):  
V. V. Vagin ◽  
N. A. Shapovalova
Keyword(s):  
Local Government ◽  
Citizen Participation ◽  
Institutional Analysis ◽  
Institutional Development ◽  
Development Programs ◽  
Theoretical Understanding ◽  
State And Local Government ◽  
State And Local ◽  
Government Initiative ◽  
Local Levels

The article is devoted to the actual issue – institutional analysis of initiative budgeting and territorial public selfgovernment, as well as the possibility of their integration. Over the past few years, a system of civil participation in budget decisions has been built in Russia, the regulatory framework of practices has been created, thousands of employees of state and local government bodies have been trained, project centers have appeared for ensuring development of initiative budgeting. Citizen participation in budget decisions can significantly accelerate the development of the lower level of local government. Initiative budgeting is an innovative instrument of public finance and at the same time a social technology allowing for the real involvement of citizens in the issues of state and municipal governance. Initiative budgeting development programs make it possible to transfer financing of projects aimed at solving local issues with the participation of citizens onto a systemic basis. The results and materials of this study can serve a foundation for theoretical understanding of the institutional development of public finances at the regional and local levels. At the same time, this practical area that was intensively developing in recent years requires deep institutional analysis.

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