Effects of Laser Irradiation on Growth and Doping Characteristics of GaAs in Chemical Beam Epitaxy

1995 ◽  
Vol 388 ◽  
Author(s):  
H. K. Dong ◽  
N. Y. Li ◽  
C. W. Tu
Keyword(s):  
Laser Irradiation ◽  
Hole Concentration ◽  
Growth Enhancement ◽  
Chemical Beam Epitaxy ◽  
Silicon Doping ◽  
Gaas Films ◽  
Ion Laser ◽  
Temperature Window ◽  
Substrate Temperatures ◽  
Incorporation Ratio

AbstractIn this paper, we report laser-assisted chemical beam epitaxy (CBE) of GaAs using triethylgallium (TEGa), tris-dimethylaminoarsenic (TDMAAs), and an ar ion laser operating at visible or ultraviolet (UV) wavelength. the laser-assisted growth with TDMAAs, compared to as4 or asH3, shows a wider range of growth enhancement at low substrate temperatures. Unlike CBE of GaAs without laser irradiation, laser-enhanced GaAs growth rate was found to be constant as the V/III incorporation ratio changes. by using diiodomethane (CI2H2) as a dopant gas, the GaAs films with laser irradiation show a much higher hole concentration than those grown simultaneously without laser irradiation at substrate temperatures from 460-530°C. Laser irradiation was also found to enhance silicon incorporation at low temperatures. Photothermal effects are responsible for laser-enhanced growth and silicon doping, but the wider temperature window in laser-enhanced growth and the laser-enhanced carbon incorporation are caused by additional photocatalytic or photochemical effects.

Chemical Beam Epitaxy (CBE) and Laser-Enhanced CBE of GaAs Using Tris-Dimethylaminoarsenic

1994 ◽  
Vol 340 ◽  
Author(s):  
H. K. Dong ◽  
N. Y. Li ◽  
C. W. Tu ◽  
M. Geva ◽  
W. C. Mitchel
Keyword(s):  
Substrate Temperature ◽  
Electron Mobility ◽  
Doping Concentration ◽  
Growth Enhancement ◽  
Chemical Beam Epitaxy ◽  
Unintentional Doping ◽  
P Type ◽  
First Time ◽  
Substrate Temperatures ◽  
Type Conduction

ABSTRACTIn this paper, we report chemical beam epitaxy (CBE) of GaAs, and for the first time, Arion laser-assisted CBE using triethylgallium (TEGa) and tris-dimethylaminoarsenic (TDMAAs), a safer alternative to arsine. Samples grown at substrate temperatures above 490° C show n-type conduction, while those grown at lower temperatures show p-type conduction. An unintentional doping concentration of n∼lx1016 cm-3 with an electron mobility of 5200 cm2/V.s at 300 K and 16000 cm2/V.s at 77 K have been achieved. These are the best results reported for GaAs grown with TDMAAs. Laser-assisted CBE of GaAs is studied in the substrate temperature range of 240-550°C. There are two different substrate-temperature regions for laser-enhanced growth, 265 to 340°C and 340 to 440°C, which are believed to be caused by different TEGa decomposition mechanisms. The laser-assisted growth with TDMAAs, compared to AS4 or AsH3, shows a wider range of growth enhancement at low substrate temperatures.

Photo Modified Growth of GaAs by Chemical Beam Epitaxy

1998 ◽  
Vol 510 ◽  
Author(s):  
R. Jothilingam ◽  
T. Farrell ◽  
T.B. Joyce ◽  
P.J. Goodhew
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Growth Rate ◽  
Electrical Power ◽  
Xenon Lamp ◽  
Chemical Beam Epitaxy ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Substrate Temperatures ◽  
Laser Reflectometry

AbstractWe report the photo modified growth of GaAs by chemical beam epitaxy at substrate temperatures in the range 335 to 670°C using triethygallium (TEG) and arsine. A mercury-xenon lamp (electrical power 200 W) provided the irradiation for the photoassisted growth. The growth was monitored in real time by laser reflectometry (LR) using a 670 nm semiconductor laser, and the optically determined growth rate agreed with that obtained from the layer thickness measured by cross sectional transmission electron microscopy. The observed photo-enhancement of the growth rate at low substrate temperatures and inhibition at high substrate temperatures is thermal in origin, consistent with raising the substrate temperature by 10±3°C. Cross sectional transmission electron microscopy showed that the photoassisted layers are essentially free from dislocations

Influence of Laser Irradiation and Ambient Gas in Preparation of PZT Films by Laser Ablation

1990 ◽  
Vol 191 ◽  
Author(s):  
Akiharu Morimoto ◽  
Shigeru Otsubo ◽  
Tatsuo Shimizu ◽  
Toshiharu Minamikawa ◽  
Yasuto Yonezawa ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Laser Irradiation ◽  
Perovskite Structure ◽  
Film Surface ◽  
Target Material ◽  
Laser Ablation Method ◽  
Wide Range ◽  
Pzt Films ◽  
Ambient Gas ◽  
Substrate Temperatures

ABSTRACTPb(Zr0.52Ti0. 48)O3 (PZT) films were prepared on r-plane sapphire substrates by the laser ablation method utilizing ArF excimer laser in O2 or N2O environment. The composition of the films deposited in O2 environment was found to be fairly close to the composition of the target material for a wide range of substrate temperatures, 400 – 750 °c. Increasing the laser fluence (the laser power density) for the ablation enhances the formation of the perovskite structure rather than the pyrochlore one. Use of N2O ambient gas instead of O2 gas enhances the formation of the perovskite structure of PZT films. Furthermore, it was found that a laser irradiation on the growing film surface during deposition enhances the formation of the perovskite structure.

Carbon Incorporation in Gaas grown by UHVCVD Using Trimethylgallium and Arsine

1992 ◽  
Vol 281 ◽  
Author(s):  
Seong-Ju Park ◽  
Jeong-Rae Ro ◽  
Jae-Ki Sim ◽  
El-Hang Lee
Keyword(s):  
Growth Rates ◽  
Hole Concentration ◽  
High Vacuum ◽  
Chemical Vapor ◽  
Ultra High Vacuum ◽  
Chemical Beam Epitaxy ◽  
Hydrogen Atoms ◽  
Carbon Incorporation ◽  
Significant Drop ◽  
P Type

ABSTRACTWe present results of a study on the effect of unprecracked arsine(AsH3) and trimethylgallium(TMGa) on carbon incorporation in UHVCVD(Ultra High Vacuum Chemical Vapor Deposition) grown GaAs epilayers on GaAs(100). Three distinct temperature-dependent regions of growth rates were identified as growth temperature was increased from 570 to 690°C. The growth rates were also strongly dependent on V/III ratio in a range of 5 to 30, which clearly indicates that the growth rate is determined by the amount of arsenic adsorbed on the surface at low V/III ratio and adsorption of TMGa or decomposition process at high V/III ratio. Hall concentration measurements and low temperature photoluminescence data show that the films are all p-type and their impurity concentrations are reduced by two orders of magnitude compared to those of epilayers grown by CBE(Chemical Beam Epitaxy) which employs TMGa and arsenic(precracked arsines) as source materials. Our results indicate that the hydrogen atoms dissociated from adsorbed arsine may remove hydrocarbon species resulting in a significant drop in hole concentration.

Effects of Ar ion laser irradiation on MOVPE of ZnSe using DMZn and DMSe as reactants

1991 ◽  
Vol 107 (1-4) ◽  
pp. 653-658 ◽  
Author(s):  
Akihiko Yoshikawa ◽  
Tamotsu Okamoto ◽  
Tsuyoshi Fujimoto
Keyword(s):  
Laser Irradiation ◽  
Ion Laser

Photoacoustic characterization of cw argon‐ion laser irradiation of Ge

1979 ◽  
Vol 35 (2) ◽  
pp. 121-124 ◽  
Author(s):  
J. F. McClelland ◽  
R. N. Kniseley
Keyword(s):  
Laser Irradiation ◽  
Argon Ion Laser ◽  
Ion Laser ◽  
Argon Ion

Low-temperature crystallization induced by excimer laser irradiation of SrBi2Ta2O9 films

2001 ◽  
Vol 16 (7) ◽  
pp. 1883-1886 ◽  
Author(s):  
Kwang Soo Seol ◽  
Hironao Hiramatsu ◽  
Yoshimichi Ohki ◽  
In-Hoon Choi ◽  
Yong-Tea Kim
Keyword(s):  
Low Temperature ◽  
Laser Irradiation ◽  
Excimer Laser ◽  
Precursor Film ◽  
Excimer Laser Irradiation ◽  
Low Temperature Crystallization ◽  
Lower Temperature ◽  
Substrate Temperatures ◽  
Induced Crystallization ◽  
Temperature Crystallization

Transition of a SrBi2Ta2O9 precursor film from amorphous to crystalline was inducedby excimer laser irradiation. Both fluorite and perovskite crystalline structures in suchfilms were obtained by excimer laser irradiation at substrate temperatures between 200and 500 °C. Either an addition of excess bismuth in the precursor film or an increasein the substrate temperature enhanced the formation of the perovskite structure in theexcimer laser-induced annealing process, resulting in the perovskite crystalline phase ata relatively lower temperature of 500 °C. Such a low temperature is preferred whenSrBi2Ta2O9 is used in ferroelectric devices. The mechanism involved in thislaser-induced crystallization is also discussed.

In-Situ Etch to Improve Chemical Beam Epitaxy Regrown AlgaAs/GaAs Interfaces for HBT Applications

1996 ◽  
Vol 448 ◽  
Author(s):  
Y.M. Hsin ◽  
N. Y. Li ◽  
C. W. Tu ◽  
P. M. Asbeck
Keyword(s):  
Etching Rate ◽  
Interface State ◽  
State Density ◽  
Interface State Density ◽  
Chemical Beam Epitaxy ◽  
Capacitance Voltage ◽  
Substrate Temperatures ◽  
Etching Effect

AbstractWe have studied the etching effect of AlxGa1-xAs (0≤ x ≤ 0.5) by trisdimethylaminoarsenic (TDMAAs) at different substrate temperatures, and the quality of the resulting etched/regrown GaAs interface. We find that the etching rate of AlxGa1-x As decreases with increasing Al composition, and the interface trap density of the TDMAAs etched/regrown interface can be reduced by about a factor of 10 as deduced from capacitance-voltage carrier profiles. A smooth surface morphology of GaAs with an interface state density of 1.4×l011 cm−2 can be obtained at a lower in-situ etching temperature of 550°C. Moreover, by using this in-situ etching the I-V characteristics of regrown p-n junctions of Al0.35Ga0.65As/Al0.25Ga0.75As and Al0.35Ga0.65As/GaAs can be improved.

Laser Induced Chemical Etching of Composite Structure of Ferrite and Sendust

1988 ◽  
Vol 129 ◽  
Author(s):  
S. Nagatomo ◽  
M. Takai ◽  
Y. F. Lu ◽  
S. Namba
Keyword(s):  
Aqueous Solutions ◽  
Laser Irradiation ◽  
Composite Structure ◽  
Chemical Etching ◽  
Etching Rate ◽  
Al Alloy ◽  
Zn Ferrite ◽  
Ion Laser ◽  
Argon Ion ◽  
Thermochemical Reaction

ABSTRACTMaskless etching of the composite structure of Mn-Zn ferrite and sendust (Fe-Si-Al alloy) was performed by focused argon-ion-laser irradiation in a CCl4 atmosphere and aqueous solutions. Only a mixture of KOH and NaOH aqueous solutions was found to smoothly etch the composite structure by thermochemical reaction using laser irradiation. A maximum etching rate of 14 μm/sec was obtained for sendust-on-ferrite substrates.

Strain-induced compositional shift in the growth of InAsyP1−y onto (100) InP by gas-source molecular beam epitaxy

1992 ◽  
Vol 70 (10-11) ◽  
pp. 886-892 ◽  
Author(s):  
C. Qiu ◽  
R. V. Kruzelecky ◽  
D. A. Thompson ◽  
D. Comedi ◽  
G. Balcaitis ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Film Thickness ◽  
Molecular Beam ◽  
Compressive Strain ◽  
Effective Strain ◽  
Depth Profiling ◽  
Group V ◽  
Gas Source ◽  
Substrate Temperatures ◽  
Incorporation Ratio

The growth of InAsyP1−y onto (100) InP by gas-source molecular beam epitaxy was examined systematically, focusing on control of the resulting As/P incorporation ratio. The group V fluxes were obtained by passing phosphine and arsine through a dual-input low-pressure gas cracker. For a given flow ratio of the source gases, the arsenic fraction y of the resulting InAsyP1−y films is seen to increase with the film thickness over the first 1500 Å (1 Å = 10−10 m) as indicated by secondary ion mass spectroscopy, Auger depth profiling, and by Rutherford backscattering spectroscopy. Thin, strained InAsyP1−y layers (0.30 < y < 0.70, corresponding to a compressive strain of about 1.0–2.2%) contain about 5–20% less As than similarly grown thicker, relaxed layers. For a given growth rate and substrate temperature, the relative compositional shift is found to be linearly proportional to the effective strain corresponding to y. Substrate temperatures above 475 °C further reduce the incorporation ratio of As into both strained and relaxed InAsyP1−y layers, initially enhancing the strain-induced compositional shift. However, strain minimization via a compositional shift competes with a greater rate of relaxation of the InAsP lattice with film thickness at higher substrate temperatures.

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