Crystal Surface Stoichiometry and the Fermi Level Effects on Outdiffusion of Si in GaAs

1992 ◽  
Vol 282 ◽  
Author(s):  
Horng-Ming You ◽  
Ulrich M. GöSele ◽  
Teh Yu Tan
Keyword(s):  
Fermi Level ◽  
Vapor Phase ◽  
Electron Concentration ◽  
Crystal Surface ◽  
Capacitance Voltage ◽  
Phase Pressure

ABSTRACTGaAs samples doped with Si to a concentration of ∼2.7×10 18cm−3 were annealed at temperatures between 800 and 1000°C for 3 to 20 hours under As-rich and As-poor conditions for Si outdiffusion which were then measured using the capacitance-voltage method employing an electrochemical profiler. The deduced Si diffusivity showed strong dependencies on the As4 vapor phase pressure, PAs4 and on the electron concentration, n. When reduced to that under intrinsic conditions, activation enthalpies of 3.91 eV and 4.19 eV were obtained for As-rich and As-poor annealing cases, respectively. From these results, it is concluded that Si outdiffusion in GaAs is governed by the triply-negatively-charged Ga vacancies, .

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.

Integration between LiNbO3 Ferroelectric Film and AlGaN/GaN System

2011 ◽  
Vol 687 ◽  
pp. 303-308 ◽  
Author(s):  
L. Z. Hao ◽  
Jun Zhu ◽  
Y. R. Li
Keyword(s):  
Electron Concentration ◽  
Electron Mobility ◽  
Ferroelectric Film ◽  
Ferroelectric Polarization ◽  
Uniform Domain ◽  
Voltage Measurement ◽  
Ferroelectric Films ◽  
External Bias ◽  
Capacitance Voltage ◽  
Gan Heterostructure

LiNbO3 film (LNO)/AlGaN/GaN heterostructure was fabricated epitaxially. The preferable C+ oriented domains in LNO film lead to the formation of the spontaneous ferroelectric polarization. As a result, the sheet electron concentration of the 2DEG (ns) decreased from 1.13×1013 cm-2 to 1.04×1013 cm-2 when a LNO film deposited on the AlGaN/GaN. The ns decreased nonlinearly with decreasing the temperature. Additionally, the electron mobility for the LNO/AlGaN/GaN heterostructure decreased greatly compared with that for AlGaN/GaN heterostructure, which was caused by the non-uniform domain structure in the LNO film. By external bias switching the ferroelectric polarization, the relative enhancement of the 2DEG, about 7.68×1011/cm2, could be accessible from capacitance-voltage measurement. These results indicated that ferroelectric films combined with AlGaN/GaN would hold promise for next-generation GaN-based memory devices.

Pressure Drop in a Capillary Tube in Boiling Two-Phase Flow

2003 ◽  
Author(s):  
Fumito Kaminaga ◽  
Baduge Sumith ◽  
Kunihito Matsumura
Keyword(s):  
Pressure Drop ◽  
Vapor Phase ◽  
Mass Flux ◽  
Two Phase Flow ◽  
Capillary Tube ◽  
Flow Boiling ◽  
Phase Flow ◽  
Two Phase ◽  
System Pressure ◽  
Phase Pressure

Two-phase pressure drop is experimentally examined in a flow boiling condition in a tube of diameter 1.45 mm using water in ranges of pressure from 10 to 100 kPa, mass flux from 18 to 152 kg/m2s, heat flux from 13 to 646 kW/m2, and exit quality from 0.02 to 0.77. Also, pressure drop in an adiabatic air-water two-phase flow is measured at atmospheric pressure using the same test section and mass flux ranges of liquid and gas as those in the flow boiling. Decreasing system pressure the pressure drop significantly increases at a given mass flux. Influence of vapor phase on the pressure drop is found to be large both in the adiabatic and the diabatic conditions. The frictional pressure drop correlation for the adiabatic two-phase flow is developed and applied to predict pressure drop in the flow boiling. But it cannot give satisfactory predictions. The Chisholm correlation calculating a two-phase pressure drop multiplier is modified to account the influence of vapor phase in a capillary tube and the modified correlation can predict the pressure drop in the flow boiling within an error of 20%.

Electrical Properties of Oxygen Doped GaN Grown by Metalorganic Vapor Phase Epitaxy

1999 ◽  
Vol 595 ◽  
Author(s):  
R.Y. Korotkov ◽  
B.W. Wessels
Keyword(s):  
Experimental Data ◽  
Electrical Properties ◽  
Vapor Phase ◽  
Electron Concentration ◽  
Formation Energy ◽  
Shallow Donor ◽  
Square Root ◽  
Compensation Ratio ◽  
Pressure Oxygen ◽  
Hall Effect Measurements

AbstractDeliberate oxygen doping of GaN grown by MOVPE has been studied. The electron concentration increased as the square root of the oxygen partial pressure. Oxygen is a shallow donor with a thermal ionization energy of 27 ±2 meV. A compensation ratio of Θ = 0.3-0.4 was determined from Hall effect measurements. The formation energy of ON of EF = 1.3 eV, determined from the experimental data, is lower than the theoretically predicted value.

Pressure Dependence of Aluminum Doping in SiC Vapor Phase Epitaxy

2004 ◽  
Vol 815 ◽  
Author(s):  
Adolf Schöner ◽  
Malin Gustafsson
Keyword(s):  
Vapor Phase ◽  
Doping Concentration ◽  
Profile Analysis ◽  
Schottky Contacts ◽  
Doping Profile ◽  
Aluminum Concentration ◽  
Analysis Method ◽  
Homoepitaxial Growth ◽  
Capacitance Voltage ◽  
Reactor Pressure

AbstractThe dependence of the aluminum incorporation on the total pressure in a hot wall vapor phase reactor for SiC homoepitaxial growth has been investigated. It was found that in the doping concentration range from 1·1017 cm−3 to 1·1019 cm−3 the incorporated aluminum concentration varies by the factor 3 to 4, when the reactor pressure is changed from 150 mbar to 250 mbar. Lower reactor pressure gives lower aluminum concentration. Periodically changing reactor pressure results in aluminum concentration periodically changing with depth in the epilayer. All results were measured electrically by capacitance-voltage measurements on nickel Schottky contacts. Additional experiments have been performed for n-type nitrogen doped SiC epilayers for comparison. The nitrogen doping concentration was found to be independent of the reactor pressure within the accuracy of the applied C-V measurements and the doping profile analysis method.

Impurity-Induced Layer Disordering: Current Understanding and Areas for Future Investigation

1989 ◽  
Vol 163 ◽  
Author(s):  
L.J. Guido ◽  
Nick Holonyak
Keyword(s):  
Experimental Data ◽  
Fermi Level ◽  
Impurity Concentration ◽  
Crystal Surface ◽  
Current Understanding ◽  
Experimental Findings ◽  
Level Effect

AbstractThe purpose of this work is to give an overview of the current phenomenological understanding of impurity-induced layer disordering (IILD). First, we identify key experimental findings such as the influence of the crystal surface-ambient interaction, the Fermi-level effect, and the impurity concentration on Al-Ga interdiffusion. Second, we review the strengths and weaknesses of existing IILD models in consideration of the above mentioned experimental data. Finally, we discuss the pitfalls involved in generalizing the results of individual Al-Ga interdiffusion experiments in order to explain a broader collection of IILD data.

Pressure Drop Study and Correlation Development for Two-Phase Flow of R134a in Annular Helicoidal Pipe

2004 ◽  
Author(s):  
H. L. Mo ◽  
R. Prattipati ◽  
C. X. Lin
Keyword(s):  
Experimental Data ◽  
Liquid Phase ◽  
Pressure Drop ◽  
Vapor Phase ◽  
Test Section ◽  
Circular Tube ◽  
Phase Flow ◽  
Two Phase ◽  
Annular Section ◽  
Phase Pressure

Pressure drop characteristics of R134a in annular helicoidal pipe was investigated experimentally with R134a flowing in the annular section. The experimental results revealed that when more R134a vapor was condensed, the liquid phase pressure drop increased largely while the vapor phase pressure drop decreased slightly. By comparing with the experimental data obtained from the same test section with R134a flowing in the inner circular tube of the helicoidal pipe, it was observed that the pressure drop for refrigerant in the annular section was always larger. It was also observed that the helicoidal pipe orientation showed little effect on the pressure drop variations. A pressure drop correlation was developed from the experimental data in terms of pressure drop multiplier with respect to Lockhart-Martinelli parameter.

scholarly journals Выращивание объёмных кристаллов AlN и GaN сублимационным сандвич-методом

2019 ◽  
Vol 61 (12) ◽  
pp. 2298
Author(s):  
Е.Н. Мохов ◽  
А.А. Вольфсон ◽  
О.П. Казарова
Keyword(s):  
Liquid Phase ◽  
Uniform Distribution ◽  
Vapor Phase ◽  
Crystal Orientation ◽  
Crystal Surface ◽  
Growth Conditions ◽  
Crystal Quality ◽  
Sandwich Method ◽  
Phase Crystal ◽  
Morphological Defects

The review of the results of growth of bulk Al and Ga nitride crystals on foreign substrates by the sublimation sandwich method (SSM) is presented. The kinetics and the mechanism of sublimation and condensation nitrides depending on the growth conditions, structure of the vapor phase, crystal orientation and the distance between the source and the seed are analyzed. It is experimentally established that by joint annealing of AlN and SiC the rate of AlN sublimation significantly increases due to formation of a liquid phase on the crystal surface. Non-uniform distribution of the liquid phase localized mainly near structural and morphological defects results in the selective nature of the surface etching, and also is the reason of deterioration of the growing crystal quality. The process of bulk AlN crystals growth with simultaneous evaporation of the seed allowing to grow crystals without cracks and with the improved parameters is realized. On SiC seeds bulk AlN crystals from 0.5 to 2 inch in diameter are grown.

Sn incorporation and electron concentration in vapor‐phase epitaxially grown GaAs

1981 ◽  
Vol 52 (1) ◽  
pp. 342-343 ◽  
Author(s):  
M. Maier ◽  
B. Hanel ◽  
P. Balk
Keyword(s):  
Vapor Phase ◽  
Electron Concentration
Sign in / Sign up

Export Citation Format

Share Document