scholarly journals Direct Growth of High-Quality InP Layers on GaAs Substrates by MOCVD

2003 ◽  
Vol 26 (2) ◽  
pp. 71-79 ◽  
Author(s):  
K. F. Yarn ◽  
W. C. Chien ◽  
C. L. Lin ◽  
C. I. Liao
Keyword(s):  
Buffer Layer ◽  
Secondary Ion Mass Spectrometry ◽  
Buffer Layers ◽  
Double Crystal ◽  
Group V ◽  
Group Iii ◽  
Metamorphic Buffer ◽  
Gaas Substrates ◽  
Temperature Group ◽  
Direct Growth

In this report, we have overcome the drawback of surface roughness of metamorphic buffer layer by LP-MOCVD technique and have grown InP metamorphic buffer layers with various thickness on misoriented GaAs (1 0 0) substrates with 10 degree towards (1 1 1)A. The grown films are characterized by optical microscopy, atomic force microscopy, secondary ion mass spectrometry, transmission electron microscopy and double-crystal X-ray diffraction. We also analyze the surface morphology, which is dependent on growth temperature, group III and group V partial pressure, growth rate and V/III ratios. A mirror-like, uniform surface and high crystal quality of the metamorphic buffer layer directly grown on a GaAs substrate can be achieved. Finally, to investigate the performance of the metamorphic microwave devices, we also fabricate the InAlAs/InGaAs metamorphic HEMT on GaAs substrates.

Improved MOCVD Growth of GaAs on Si

1987 ◽  
Vol 91 ◽  
Author(s):  
R.M. Lum ◽  
J.K. Klingert ◽  
B.A. Davidson ◽  
M.G. Lamont
Keyword(s):  
Buffer Layer ◽  
Rutherford Backscattering Spectrometry ◽  
Growth Parameters ◽  
Buffer Layers ◽  
Double Crystal ◽  
Gaas On Si ◽  
Mocvd Growth ◽  
Gaas Films ◽  
Gaas Buffer Layer ◽  
Direct Growth

ABSTRACTIn the direct growth of GaAs on Si by MOCVD the overall quality of the heteroepitaxial film is controlled to a large extent by the growth parameters of the initial GaAs buffer layer. We have investigated the structural properties of this layer using Rutherford Backscattering Spectrometry (RBS) and X-ray double crystal diffractometry. The crystallinity of the buffer layer was observed to improve with increasing layer thickness in the range 10–100nm, and then to rapidly degrade for thicker layers. High temperature (750°C) annealing of the buffer layers resulted in considerable reordering of all but the thicker (>200 nm) layers. Alteration of the usual GaAs/Si growth sequence to include an in-situ anneal of the buffer layer after growth interruption yielded GaAs films with improved structural, optical and electrical properties.

Heteroepitaxial Growth of ImP and GaInAs on GaAs Substrates Using Tertiarybutylarsine and Tertiarybutylphosphine

1990 ◽  
Vol 198 ◽  
Author(s):  
Shirley S. Chu ◽  
T. L. Chu ◽  
C. H. Yoo ◽  
G. L. Smith
Keyword(s):  
Buffer Layer ◽  
New Combination ◽  
Molar Ratio ◽  
Heteroepitaxial Growth ◽  
Group V ◽  
Growth Step ◽  
Group Iii ◽  
Good Surface ◽  
Gaas Substrates ◽  
Horizontal Reactor

ABSTRACTThe heteroepitaxial growth of InP and GaInAs on GaAs substrates has been studied by using a new combination of source materials: ethyldimethylindium (EDMIn) and trimethylgallium (TMGa) or triethylgallium (TEGa) as group III sources, and tertiarybutylphosphine (TBP) and tertiarybutylarsine (TBAs) as group V sources. The heteroepitaxial growth was carried out in a horizontal reactor in H2 under atmospheric pressure using a 2 kW quartz lamp as the substrate heater. Epitaxial InP layers of good surface morphology were obtained by using a two step process. The continuity and thickness of the buffer layer are important parameters. The InP layers deposited at 600°C are n-type, and the electron concentration decreases with decreasing TBP/EDMIn molar ratio. The 4.2 K photoluminescence of InP films is very similar to that of homoepitaxial InP films deposited at 600°C using trimethylindium (TMIn) and phosphine. Epitaxial GaxIn1–xAs layers with In composition varying from 3% to 53% have been deposltedi on GaAs substrates at 500° -550°C. A single growth step can be used for the deposition of GaxIn1–xAs with In composition of less than 20%. An InP buffer layer was used when the GaxIn1–xAS layer contains about 53% In. The composition of GaInAs was determined by optical absorption and photoluminescence techniques.

Photodetectors with an InGaAs Active Region and InGaP Metamorphic Buffer Layer Grown on GaAs Substrates

2018 ◽  
Vol 52 (12) ◽  
pp. 1564-1567
Author(s):  
I. V. Samartsev ◽  
S. M. Nekorkin ◽  
B. N. Zvonkov ◽  
V. Ya. Aleshkin ◽  
A. A. Dubinov ◽  
...  
Keyword(s):  
Active Region ◽  
Buffer Layer ◽  
Metamorphic Buffer ◽  
Gaas Substrates

scholarly journals 1.06 μm wavelength photodetectors with metamorphic buffer layers grown on GaAs substrates

2018 ◽  
Vol 1124 ◽  
pp. 041037
Author(s):  
I V Samartsev ◽  
S M Nekorkin ◽  
B N Zvonkov ◽  
N V Dikareva ◽  
A V Zdoroveyshchev ◽  
...  
Keyword(s):  
Buffer Layers ◽  
Metamorphic Buffer ◽  
Gaas Substrates

Equilibrium Lattice Relaxation and Misfit Dislocations in Continuously- and Step-Graded InxGa1-xAs/GaAs (001) and GaAs1-yPy/GaAs (001) Metamorphic Buffer Layers

2015 ◽  
Vol 24 (03n04) ◽  
pp. 1520009 ◽  
Author(s):  
Tedi Kujofsa ◽  
John E. Ayers
Keyword(s):  
Dislocation Density ◽  
Buffer Layer ◽  
Minimum Energy ◽  
Lattice Relaxation ◽  
Structure Type ◽  
Elastic Stiffness ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Misfit Dislocations ◽  
Metamorphic Buffer

The inclusion of metamorphic buffer layers (MBL) in the design of lattice-mismatched semiconductor heterostructures is important in enhancing reliability and performance of optical and electronic devices. These metamorphic buffer layers usually employ linear grading of composition, and materials including InxGa1-xAs and GaAs1-yPy have been used. Non-uniform and continuously graded profiles are beneficial for the design of partially-relaxed buffer layers because they reduce the threading dislocation density by allowing the distribution of the misfit dislocations throughout the metamorphic buffer layer, rather than concentrating them at the interface where substrate defects and tangling can pin dislocations or otherwise reduce their mobility as in the case of uniform compositional growth. In this work we considered heterostructures involving a linearly-graded (type A) or step-graded (type B) buffer layer grown on a GaAs (001) substrate. For each structure type we present minimum energy calculations and compare the cases of cation (Group III) and anion (Group V) grading. In addition, we studied the (i) average and surface in-plane strain and (ii) average misfit dislocation density for heterostructures with various thickness and compositional profile. Moreover, we show that differences in the elastic stiffness constants give rise to significantly different behavior in these two commonly-used buffer layer systems.

Initial Buffer Layers on the Growth of InGaP on Si by MBE

1996 ◽  
Vol 441 ◽  
Author(s):  
H. Kawanami ◽  
S. Ghosh ◽  
I. Sakata ◽  
T. Sekigawa
Keyword(s):  
High Temperature ◽  
Surface Structure ◽  
Buffer Layer ◽  
Molecular Beam ◽  
Single Domain ◽  
Buffer Layers ◽  
Structure Control ◽  
Si Substrates ◽  
Direct Growth ◽  
Initial Buffer

AbstractSingle domain InxGa(1-x)P (x=0.3) films were successfully grown on Si(001) misoriented substrates by molecular beam epitaxy with a solid phosphorous source. The effects of interfacial buffer layers such as InGaP (i.e. direct growth without buffer layer), GaP, AlP, and GaAs were examined. Also a Si epitaxial buffer layer was tried to control the Si surface structure. Mirror like surfaces were obtained for all films with RHEED patterns of (2×1) single domain surface structure. PL intensities for all films indicated almost the same values except for the films with a Si epitaxial buffer layer. The films with a Si epitaxial buffer layer had almost three times larger PL intensities than the films without Si epitaxial buffer layer. The results suggest incomplete cleaning of the Si surface by the high temperature (1000 °C) treatment and possibility of surface structure control for Si substrates by a Si epitaxial buffer layer.

Preparation of PbZrxTi1−xO3 Films on Si Substrates Using SrTiO3 Buffer Layers

1994 ◽  
Vol 361 ◽  
Author(s):  
Eisuke Tokumitsu ◽  
Kensuke Itani ◽  
Bum-Ki Moon ◽  
Hiroshi Ishiwara
Keyword(s):  
Buffer Layer ◽  
Secondary Ion Mass Spectrometry ◽  
Sol Gel ◽  
Buffer Layers ◽  
Si Substrates ◽  
Pzt Film ◽  
Pzt Films ◽  
Evaporation Technique ◽  
Gel Technique ◽  
Secondary Ion

ABSTRACTWe report the preparation of PbZrxTi1−xO3 (PZT) films on Si substrates with a SrTiO3 (STO) buffer layer. STO buffer layers and PZT films were formed on Si substrates by the electron-beam assisted vacuum evaporation technique and sol-gel technique, respectively. By evaporating a thin (8nm) metal Sr layer prior to the STO deposition, which deoxidizes the SiO2 layer at the Si surface, (100)- and (111)-oriented STO thin films can be grown on Si(100) and (111) substrates, respectively. It is shown that a strongly (100)-oriented PZT film is grown on STO(100)/Si(100), whereas a strongly (111)-oriented PZT film is obtained on STO(111)/Si(111). It is also found that the STO buffer layer remains intact even after the PZT deposition. Secondary ion mass spectrometry (SIMS) analysis showed that the STO barrier layer was effective in preventing diffusion of Pb into the Si substrate.

Deposition Sequences for Atomic Layer Growth of AlN Thin Films on Si(100) Using Dimethylethylamine Alane and Ammonia

1997 ◽  
Vol 482 ◽  
Author(s):  
Jason S. Kuo ◽  
J. W. Rogers
Keyword(s):  
Mass Spectrometry ◽  
Thin Films ◽  
Secondary Ion Mass Spectrometry ◽  
Atomic Layer ◽  
Layer Growth ◽  
Group V ◽  
Group Iii ◽  
Dimethylethylamine Alane ◽  
Temperature Programmed ◽  
Secondary Ion

AbstractRecent studies have demonstrated that dimethylethylamine alane (DMEAA) is a viable group III precursor for depositing high quality aluminum nitride thin films during atomic layer growth with ammonia as the group V source. However, a practical consideration that is questioned but seldom investigated is whether one should initiate the growth with the group III or the group V source. Clearly DMEAA interacts differently with silicon than does ammonia; hence, reversing the deposition sequence will lead to different interfacial composition. Earlier studies involving TMAA and ammonia indicate that direct interaction of group III precursor with the surface may lead to higher carbon contamination. In this work, adsorption of DMEAA on Si(100) and on ammonia-covered Si(100) are characterized with Temperature-Programmed Desorption (TPD), Secondary-Ion Mass Spectrometry (SIMS), and Temperature-Programmed Secondary-Ion Mass Spectrometry (TPSIMS). Preliminary results indicate that DMEAA adsorbs molecularly on both Si(100) and ammonia-covered Si(100), but to a much smaller coverage on the latter surface. Results from reversing the adsorption sequence, i.e. ammonia first then DMEAA, will be compared as a possibility for interfacial quality control.

scholarly journals Evolution of Epilayer Tilt in InGaAs Metamorphic Buffer Layers Grown by HVPE

2014 ◽  
Vol 70 (a1) ◽  
pp. C235-C235
Author(s):  
Kevin Schulte ◽  
Thomas Kuech
Keyword(s):  
Dislocation Nucleation ◽  
Hydride Vapor Phase Epitaxy ◽  
Buffer Layers ◽  
Slip Systems ◽  
X Ray Diffraction ◽  
Burgers Vector ◽  
X Ray ◽  
Metamorphic Buffer ◽  
Gaas Substrates ◽  
Graded Structures

Tilt behavior in InxGa1-xAs metamorphic buffer layers (MBLs) grown by hydride vapor phase epitaxy (HVPE) was measured by high resolution x-ray diffraction (HRXRD). Step- and continuously-graded structures were grown on exactly (001) oriented GaAs substrates as well as on substrates with a miscut of 40→ (111)B of (001). Growth temperature and final In composition were varied as well. HRXRD Ω-F mapping was employed to independently resolve both the magnitude and direction of tilt as a function of depth throughout each structure. Tilt azimuth was initially random in growths on nominally (001) oriented substrates and changed as grading continued, moving closer to [110]. Tilt magnitude increased more linearly and to larger values as a function of xInAs in the step-graded vs. continuously graded samples. MBLs grown on 40miscut substrates tilted in the opposite direction of the miscut surface normal, and the tilt magnitude for a given xInAs was greater than for planar samples. When the tilt vectors of the miscut samples were resolved along the orthogonal [-110] and [110] directions it was found that the tilt was much stronger along the direction that the miscut was aligned, or [-110]. Tilt in the planar samples increased monotonically and to larger magnitudes along [110] compared with [-110]. The behavior on miscut samples can be attributed to the preferential generation of dislocations on slip systems which experience a larger resolved shear stress due to the miscut [1]. The tilt anisotropy in planar samples can be attributed to the fact that dislocation cores and core energies in III-V semiconductors are also anisotropic [2]. Dislocation nucleation along [110] has a higher activation energy, so a larger proportion of dislocations is likely generated by multiplication sources, creating arrays of dislocations possessing the same burgers vector. Dislocation distributions in samples grown at high temperature were found to be more uniform, overcoming these barriers.

scholarly journals H Out-Diffusion and Device Performance in n-i-p Solar Cells Utilizing High Temperature Hot Wire a-Si:H i-Layers

1998 ◽  
Vol 507 ◽  
Author(s):  
A. H. Mahan ◽  
R. C. Reedy ◽  
E. Iwaniczko ◽  
Q. Wang ◽  
B. P. Nelson ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Buffer Layer ◽  
Diffusion Coefficients ◽  
Chemical Potential ◽  
Secondary Ion Mass Spectrometry ◽  
Buffer Layers ◽  
Device Performance ◽  
Hot Wire ◽  
Defective Layer

ABSTRACTHydrogen out-diffusion from the n/i interface region plays a major role in controlling the fill factor (FF) and resultant efficiency of n-i-p a-Si:H devices, with the i-layer deposited at high substrate temperatures by the hot wire technique. Modeling calculations show that a thin, highly defective layer at this interface, perhaps caused by significant H out-diffusion and incomplete lattice reconstruction, results in sharply lower device FF's due to the large voltage dropped across this defective layer. One approach to this problem is to introduce trace dopant tailing to ‘compensate’ these defects, but the resultant cells exhibit a poor red response. A second approach involves the addition of buffer layers designed to retard this out-diffusion. We find that an increased H content, either in the n-layer or a thin intrinsic low temperature buffer layer, does not significantly retard this out-diffusion, as observed by secondary ion mass spectrometry (SIMS) H profiles on devices. All these devices have a defect-rich i-layer region near the n/i interface and a poor device efficiency. However, if this low temperature buffer layer is thick enough, the outdiffusion is minimized, yielding nearly flat H profiles and a much improved device performance. We discuss this behavior in the context of the H chemical potentials and H diffusion coefficients in the high temperature, buffer, n-, and stainless steel (SS) substrate layers. The chemical potential differences between the layers control the direction of the H flow and the respective diffusion coefficients, which depend upon many factors such as the local electronic Fermi energy and the extent of the H depletion, determine the rate. Finally, we report a 9.8% initial active area device, fabricated at 16Å/s, using the insights obtained in this study.

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