Study of Modulation in GaAs Misfets with LT-GaAs as a Gate Insulator

1991 ◽  
Vol 241 ◽  
Author(s):  
L.-W. Yin ◽  
J. Ibbetson ◽  
M. M. Hashemi ◽  
W. Jiang ◽  
S.-Y. Hu ◽  
...  
Keyword(s):  
Low Temperature ◽  
Gaas Layer ◽  
Gate Insulator ◽  
Gate Bias ◽  
Channel Current ◽  
Turn On ◽  
Dc Characteristics ◽  
Low Temperature Gaas ◽  
Channel Separation ◽  
Lt Gaas

ABSTRACTDC characteristics of a GaAs MISFET structure using low-temperature GaAs (LTGaAs) as the gate insulator were investigated. MISFETs with different gate to channel separation (d) were fabricated. The dependence of four important device parameters such as gate-drain breakdown voltage (VBR), channel current at zero gate bias (Idss), transconductance (gm), and gate-drain turn-on voltage (Von) on the gate insulator thickness were analyzed. It was observed that (a) in terms of Idss and gin, the LT-GaAs gate insulator behaves like an undoped regular GaAs layer and (b) in terms of VBR and Von, the LT-GaAs gate insulator behaves as a trap dominated layer.

Laser Quality AlGaAs-GaAs Quantum Wells Grown on Low Temperature GaAs

1991 ◽  
Vol 241 ◽  
Author(s):  
Y. Hwang ◽  
D. Zhang ◽  
T. Zhang ◽  
M. Mytych ◽  
R. M. Kolbas
Keyword(s):  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Quantum Wells ◽  
Barrier Layer ◽  
Molecular Beam ◽  
Optical Quality ◽  
First Order ◽  
Gaas Buffer Layer ◽  
Low Temperature Gaas ◽  
Lt Gaas

ABSTRACTIn this work we demonstrate that photopumped quantum wellheterostructure lasers with excellent optical quality can be grown ontop of a LT GaAs buffer layer by molecular beam epitaxy. Hightemperature thermal annealing of these lasers blue-shifts the laseremission wavelengths but the presence/absence of a LT GaAs layerhad little effect on the overall laser thresholds. Also, to first order itwas not necessary to include an AlAs barrier layer to preventadverse effects (as has been necessary in the gate stack of MESFETs to prevent carrier compensation).

scholarly journals Influence of Low Temperature-Grown GaAs on Lateral Thermal Oxidation of Al0.98Ga0.02As

2000 ◽  
Vol 623 ◽  
Author(s):  
J. C. Ferrer ◽  
Z. Liliental-Weber ◽  
H. Reese ◽  
Y.J. Chiu ◽  
E. Hu
Keyword(s):  
Low Temperature ◽  
Thermal Oxidation ◽  
Oxidation Process ◽  
Gaas Layer ◽  
Transmission Electron ◽  
Low Temperature Gaas ◽  
Reference Samples ◽  
Thermal Oxidation Process ◽  
Low Temperature Grown Gaas

AbstractThe lateral thermal oxidation process of Al0.98Ga0.02As layers has been studied by transmission electron microscopy. Growing a low-temperature GaAs layer below the Al0.98Ga0.02As has been shown to result in better quality of the oxide/GaAs interfaces compared to reference samples. While the later have As precipitation above and below the oxide layer and roughness and voids at the oxide/GaAs interface, the structures with low-temperature have less As precipitation and develop interfaces without voids. These results are explained in terms of the diffusion of the As toward the low temperature layer. The effect of the addition of a Si02 cap layer is also discussed.

Spectroscopic Ellipsometric Characterization of Low Temperature GaAs

1995 ◽  
Vol 378 ◽  
Author(s):  
X. Gao ◽  
P. G. Snyder ◽  
P. W. Yu ◽  
Y. Q. Zhang ◽  
Z. F. Peng
Keyword(s):  
Low Temperature ◽  
Red Shift ◽  
Strain Effect ◽  
Lorentz Oscillator ◽  
Ellipsometric Characterization ◽  
C 30 ◽  
Low Temperature Gaas ◽  
Low Temperature Grown Gaas ◽  
Lt Gaas

AbstractPseudodielectric functions of low temperature grown GaAs (LT GaAs) measured by spectroscopic ellipsometry are presented. The spectral range includes the El (2.92eV) and El+ΔAl (3.13eV) critical point structure of GaAs. A Lorentz-oscillator model was used to fit the dielectric function of LT GaAs for samples with nominal growth temperatures (Tg) varying from 200°C to 580°C. For Tg of 200°C, 30% and 19% broadenings and −0.01 leV and −0.007eV red shifts were found for the El and El+Δl structures respectively, compared with normal GaAs. The red shift can be explained in terms of a strain effect in the LT layer. In annealed LT GaAs the broadening decreased significantly and no red shift was found.

Effect of thermal annealing on the photoluminescence of structures with InGaAs/GaAs quantum wells and a low-temperature GaAs layer δ-doped with Mn

2016 ◽  
Vol 50 (11) ◽  
pp. 1469-1474
Author(s):  
I. L. Kalentyeva ◽  
O. V. Vikhrova ◽  
Yu. A. Danilov ◽  
B. N. Zvonkov ◽  
A. V. Kudrin ◽  
...  
Keyword(s):  
Low Temperature ◽  
Quantum Wells ◽  
Thermal Annealing ◽  
Gaas Layer ◽  
Low Temperature Gaas

DLTS Study on Annealed Low-Temperature GaAs Layers with An n-I(LT)-n Structure Grown by MBE

1995 ◽  
Vol 378 ◽  
Author(s):  
Tsai-Cheng Lin ◽  
Hiromasa T Kaibe ◽  
Tsugunori Okumura
Keyword(s):  
Low Temperature ◽  
Molecular Beam ◽  
Deep Level ◽  
Gaas Layer ◽  
Electron Trap ◽  
Molecular Beam Epitaxial ◽  
Sample Structure ◽  
Transient Spectroscopy ◽  
Low Temperature Gaas ◽  
Substrate Temperatures

AbstractDeep levels in the annealed low-temperature molecular beam epitaxial (LT-MBE) GaAs layer were successfully characterized by using the capacitance deep-level transient spectroscopy (C-DLTS) as well as photocapacitance quenching technique in combination with a unique sample structure. In this work, we have fabricated the samples by inserting the LT-GaAs layer into two n-type semi-conductive layers, like a sandwich (n-LT-n structure), grown at normal substrate temperatures. DLTS measurements have revealed that one electron trap dominates the annealed LT-MBE GaAs. The dominant electron trap was very similar to the so-called EL3 level. Moreover, we found the midgap level appeared upon 800-900°C RTA, although no midgap level was detected in the as-grown n-LT-n sample (annealed at 620°C) and confirmed with photoquenching measurements that it is the EL2 level.

Atomic Structure of Twinned As Precipitates in Lt-GaAs

1998 ◽  
Vol 4 (S2) ◽  
pp. 664-665
Author(s):  
S. Ruvimov ◽  
Ch. Dicker ◽  
J. Washburn ◽  
Z. Liliental-Weber
Keyword(s):  
High Resolution Electron Microscopy ◽  
Gaas Layer ◽  
High Resistivity ◽  
Rhombohedral Structure ◽  
Special Focus ◽  
Resolution Electron ◽  
Device Applications ◽  
Polyhedral Shape ◽  
Low Temperature Gaas ◽  
Lt Gaas

Low-temperature GaAs (LT-GaAs) of a high resistivity and a short carrier lifetime (0.2-20 ps) is promising for device applications. High temperature annealing of LT-GaAs often leads to formation of twinned As precipitates in the GaAs matrix. Here high resolution electron microscopy has been applied to study the structure of As precipitates formed in MBE grown LT-GaAs layers during rapid thermal annealing at 850 and 950 °C. Twinning in the rhombohedral As was a special focus of this study.Fig. 1 shows a HREM image of a typical As precipitate formed in a LT-GaAs layer after annealing at 850 °C. The precipitate has a rhombohedral structure with a=0.376 nm and c= 1.055 nm and a polyhedral shape with distinct facets. The long facets bounded by the {111}A planes of the GaAs are planar while the others have a high density of steps.

A precursor to the breakdown of homogeneous growth in low temperature MBE GaAs detected by ellipsometry

1995 ◽  
Vol 53 ◽  
pp. 470-471
Author(s):  
S. D. Walck ◽  
K. G. Eyink ◽  
T. W. Haas ◽  
B. G. Streetman
Keyword(s):  
Low Temperature ◽  
Strain Energy ◽  
Strain Relaxation ◽  
Gaas Layer ◽  
High Crystalline Quality ◽  
Insulating Layer ◽  
The Past ◽  
Lattice Matched ◽  
Lt Gaas

GaAs grown by MBE at low temperature (LT) in the range of 150-250°C forms a highly resistive film after it has been annealed. The high resistance of annealed LT-GaAs has been use to provide a semi-insulating layer lattice-matched to GaAs. For this reason, LT layers must have reproducible properties and must be of high crystalline quality for subsequent epitaxial layers. The as-grown LT-GaAs typically has 1-2% excess As which is responsible for an increase in the lattice constant of about 0.1 %. The thickness of the LT-GaAs layer is limited by the strain energy in the film which leads to the formation of pyramidal defects which is known as the critical thickness, hc. In-situ single wavelength ellipsometry has been used to precisely set a reference temperature for a given As beam equivalent pressure (BEP) which can be used to grow reproducible LT-GaAs layers. In the past, XTEM has been used to determine hc, however, in-situ ellipsometry can also be used to monitor the film’s optical properties during growth and can detect the different regions from breakdown of homogeneous growth through the film’s strain relaxation by the generation of the pyramidal defects to the formation of polycrystalline GaAs, if the growth is allowed to continue that far. An XTEM micrograph of such a film with the growth regions defined is shown in Fig. 1.

Experimental Studies of New GaAs Metal/Insulator/p-n+Switches Using Low Temperature Oxide

2002 ◽  
Vol 25 (3) ◽  
pp. 233-237
Author(s):  
K. F. Yarn
Keyword(s):  
Low Temperature ◽  
Negative Differential Resistance ◽  
Doping Concentration ◽  
Experimental Studies ◽  
Differential Resistance ◽  
Switching Behavior ◽  
Metal Insulator ◽  
Turn On ◽  
Temperature Oxide ◽  
Phase Chemical

First observation of switching behavior is reported in GaAs metal-insulator-p-n+structure, where the thin insulator is grown at low temperature by a liquid phase chemical-enhanced oxide (LPECO) with a thickness of 100 Å. A significant S-shaped negative differential resistance (NDR) is shown to occur that originates from the regenerative feedback in a tunnel metal/insulator/semiconductor (MIS) interface andp-n+junction. The influence of epitaxial doping concentration on the switching and holding voltages is investigated. The switching voltages are found to be decreased when increasing the epitaxial doping concentration, while the holding voltages are almost kept constant. A high turn-off/turn-on resistance ratio up to105has been obtained.

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