Application of the Amphoteric Native Defect Model to Diffusion and Activation of Shallow Impurities in III-V Semiconductors

1993 ◽  
Vol 300 ◽  
Author(s):  
W. Walukiewicz
Keyword(s):  
Fermi Level ◽  
Defect Formation ◽  
Doped Semiconductors ◽  
Model Calculations ◽  
Impurity Atoms ◽  
Dependent Part ◽  
Localized Defects ◽  
Shallow Impurities ◽  
And Diffusion ◽  
Lattice Matched

ABSTRACTThe effects of heavy doping on the formation of charged point defects are considered. It is shown that the Fermi level dependent part of the formation energy of highly localized defects can be determined using a universal energy reference, common to all III-V compound semiconductors. The concept is used to analyze the electrical activity and diffusion of dopant impurities in these compounds. We present model calculations which explain the correlation between the maximum hole concentrations and the acceptor impurity diffusion in InP and in InGaAs alloys, doped with group II acceptors. The calculations account for the redistribution of the impurity atoms at the lattice matched InP/InGaAs interface. It is also demonstrated that an abrupt enhancement of the Fermi level induced defect formation is observed at the onset of highly degenerate statistics in heavily doped semiconductors.

THE STABILITY OF LOW INDEX METAL SURFACES TO TOPOLOGICAL DEFECTS

1991 ◽  
Vol 05 (03) ◽  
pp. 427-459 ◽  
Author(s):  
EDWARD H. CONRAD
Keyword(s):  
Metal Surfaces ◽  
Surface Defects ◽  
Defect Formation ◽  
Fundamental Problem ◽  
Topological Defects ◽  
Surface Roughening ◽  
Thermal Generation ◽  
Diffusion Mechanisms ◽  
The Stability ◽  
And Diffusion

The study of defect formation at metal surfaces is a fundamental problem in surface physics. An understanding of defect formation is pertinent to growth and diffusion mechanisms. In addition, surface roughening, faceting, and surface melting are all defect mediated phase transitions involving the formation of different topological defects. While the importance of defects at surfaces is well recognized, the study of surface defects has been hampered by the lack of sufficiently accurate experimental techniques. In fact, it is only in the past 6 years that experiments on the thermal generation of defects on metal surfaces have been performed. This review attempts to outline both the theoretical and experimental work on surface defect formation on metal systems.

Pressure and Strain Effects on Diffusion

1989 ◽  
Vol 163 ◽  
Author(s):  
A. Antonelli ◽  
J. Bernholc
Keyword(s):  
Hydrostatic Pressure ◽  
Formation Energy ◽  
Defect Formation ◽  
Nearest Neighbors ◽  
Diffusion Barriers ◽  
Impurity Diffusion ◽  
Strain Effects ◽  
Self Diffusion ◽  
Lattice Matched

AbstractWe have investigated, via parameter-free calculations, the effects of hydrostatic and nonhydrostatic strains on the energetics of defect formation and self-diffusion in silicon. The three microscopic mechanisms, vacancy, interstitial, and concerted exchange, have very similar activation enthalpies at zero pressure but exhibit different behavior with hydrostatic pressure. Our results suggest that experiments performed at different pressures can determine the relative contributions of each of these mechanisms. The calculations also show that the neutral Si vacancy has a negative relaxation volume, with the nearest neighbors of the vacancy relaxing inwards, in contrast to the Si (111) surface. Large nonhydrostatic strains, which are present in e.g. Si/GexSi1-x pseudomorphic heterostractures, substantially reduce the formation energy of the tetrahedral interstitial, but do not affect the formation energy of the vacancy. These findings suggest that, aside from being another useful tool for the investigation of self-diffusion in Si, nonhydrostatic strain may significantly affect annealing and impurity diffusion in strained heterostructures. In particular, the interstitial-assisted impurity diffusion may proceed more rapidly in Si lattice-matched to GexSi1-x, but be slowed down in GexSi1-x lattice-matched to Si. The compressed GexSi1-x layers may thus act as diffusion barriers for impurities diffusing with help of native interstitials, such as B or P.

Theory and Simulation of Dopant Diffusion in SiGe

2003 ◽  
Vol 765 ◽  
Author(s):  
Chun-Li Liu ◽  
Marius Orlowski ◽  
Aaron Thean ◽  
Alex Barr ◽  
Ted White ◽  
...  
Keyword(s):  
Volume Change ◽  
Defect Formation ◽  
Formation Enthalpy ◽  
Lattice Expansion ◽  
Strained Si ◽  
P Diffusion ◽  
Expansion Theory ◽  
The Difference ◽  
And Diffusion ◽  
Good Agreement

AbstractStrained Si-based technology has imposed a new challenge for understanding dopant implantation and diffusion in SiGe that is often used as the buffer layer for a strained Si cap layer. In this work, we describe our latest modeling effort investigating the difference in dopant implantation and diffusion between Si and SiGe. A lattice expansion theory was developed to account for the volume change due to Ge in Si and its effect on defect formation enthalpy. The theory predicts that As diffusion in SiGe is enhanced by a factor of ∼10, P diffusion by a factor of ∼2, and B diffusion is retarded by a factor of ∼6, when compared to bulk Si. These predictions are consistent with experiment. Dopant profiles for As, P, and B were simulated using process simulators FLOOPS and DIOS. The simulated profiles are in good agreement with experiment.

Effects of Impurities on the Optical Properties of Quantum Dots, Wires, and Multiple Wells

1993 ◽  
Vol 325 ◽  
Author(s):  
Garneit W. Bryant
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Simple Model ◽  
Radiative Recombination ◽  
Confined Systems ◽  
Electron Hole ◽  
Model Calculations ◽  
Shallow Impurities ◽  
Impurities And Defects

AbstractIdentifying and understanding the effects of impurities and defects in quantum dots, wires, and multiple wells is important for the development of nanostructures with good optical properties. Simple model calculations are presented to show when and how shallow impurities affect the radiative recombination of confined electron-hole pairs. Results for nanostructures are compared with results for bulk systems. Qualitative differences between bulk and confined systems are described.

Effect of Bias on Recovery Rates of Stressed Amorphous Silicon Mis Structures

1990 ◽  
Vol 192 ◽  
Author(s):  
W. B. Jackson ◽  
M. Hack
Keyword(s):  
Fermi Level ◽  
Amorphous Silicon ◽  
Conduction Band ◽  
Defect Formation ◽  
Defect States ◽  
Theoretical Understanding ◽  
Fermi Level Position ◽  
Electron Accumulation ◽  
Capacitance Voltage ◽  
Mis Structures

ABSTRACTThe effect of Fermi level position on the annealing of defects created by electron accumulation is investigated. Results indicate that holes accelerate the annealing of defects created by electrons confirming the theoretical understanding of the proximity compensated layer. Capacitance-voltage curves indicate that hole accumulation tends to create defect states located closer to the conduction band than electron accumulation–a result in agreement with energetics of defect formation.

Formation of Vacancies and Divacancies in Plane-Stressed Silicon

2005 ◽  
Vol 108-109 ◽  
pp. 433-438 ◽  
Author(s):  
S. Nicolaysen ◽  
Mariya G. Ganchenkova ◽  
Risto M. Nieminen
Keyword(s):  
Band Structure ◽  
Fermi Level ◽  
Plane Stress ◽  
First Principles ◽  
Defect Formation ◽  
Lattice Relaxation ◽  
Structure Modification ◽  
Strain Magnitude ◽  
Formation Energies ◽  
Elastic Lattice

The effect of compressive and tensile plane-stress loading on formation energies and electronic properties of vacancies and divacancies in silicon are studied by first-principles approach for in-plane strains up to 0.7%. It is demonstrated that contributions to defect formation energies from the elastic lattice relaxation and from the band structure modification respond to stress in a different manner, leading to noticeable different behaviour of formation energies for different charges states. The most stable vacancy charge states at different Fermi level are shown to be sensitive to strain magnitude and sign. This results in the strain-induced shifts and even disappearance of some of thermal ionization levels of vacancies and divacancies in the band gap.

Fermi level-dependent defect formation at Cu(In,Ga)Se2 interfaces

2000 ◽  
Vol 166 (1-4) ◽  
pp. 508-512 ◽  
Author(s):  
A. Klein ◽  
J. Fritsche ◽  
W. Jaegermann ◽  
J.H. Schön ◽  
Ch. Kloc ◽  
...  
Keyword(s):  
Fermi Level ◽  
Defect Formation
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