Optimisation Of The Heteroepitaxy Of Ge On GaAs For Minority-Carrier Lifetime

1990 ◽  
Vol 198 ◽  
Author(s):  
R. Venkatasubramanian ◽  
M.L. Timmons ◽  
S. Bothra ◽  
J.M. Borrego
Keyword(s):  
High Temperature ◽  
Buffer Layer ◽  
Gaas Substrate ◽  
Carrier Lifetime ◽  
Minority Carrier ◽  
High Growth ◽  
Minority Carrier Lifetime ◽  
Layer Growth ◽  
Buffer Layers ◽  
Temperature Growth

ABSTRACTGrowth of Ge on GaAs at reasonably high temperatures, which produce better crystallinity in the Ge, presents serious difficulties due to the dissociation of the GaAs substrate. In this paper, we describe the growth of a lowtemperature buffer layer of Ge on GaAs that prevents decomposition of the GaAs during high-temperature growth of Ge. Using this approach, we present the first report of highly specular, mass-transport-limited high-temperature growth of Ge on GaAs that is comparable to the homoepitaxy of Ge. The factors affecting the minority-carrier lifetime of Ge on GaAs, using such an epitaxial growth technique, were studied with a non-invasive microwave technique. Lifetime variations, from very low values to about 0.45 μsec, were obtained as a function of the growth conditions. Significantly, the removal of the surface oxide on the GaAs substrate prior to low-temperature buffer-layer growth, terminating the flow of germane(GeH4) during the ramp to high growth temperatures, thinner buffer layers, and high-temperature growth of Ge were found to be important for obtaining long lifetimes.

InAs1-xSbx ALLOYS WITH NATIVE LATTICE PARAMETERS GROWN ON COMPOSITIONALLY GRADED BUFFERS: STRUCTURAL AND OPTICAL PROPERTIES

2012 ◽  
Vol 21 (01) ◽  
pp. 1250013
Author(s):  
D. WANG ◽  
D. DONETSKY ◽  
Y. LIN ◽  
G. KIPSHIDZE ◽  
L. SHTERENGAS ◽  
...  
Keyword(s):  
Optical Properties ◽  
Buffer Layer ◽  
Lattice Constant ◽  
Carrier Lifetime ◽  
Minority Carrier ◽  
Minority Carrier Lifetime ◽  
Lattice Parameters ◽  
Buffer Layers ◽  
Structural And Optical Properties ◽  
Lattice Constants

GaInSb and AlGaInSb compositionally graded buffer layers grown on GaSb by MBE were used to develop unrelaxed InAs1-xSbx epitaxial alloys with strain-free native lattice constants up to 2.1% larger than that of GaSb . The in-plane lattice constant of the strained top buffer layer was grown to be equal to the native, unstrained lattice constant of InAs1-xSbx with given x. The InAs0.56Sb0.44 layers demonstrated a photoluminescence (PL) peak at 9.4 μm at T = 150 K. The minority carrier lifetime measured at 77 K for InAs0.8Sb0.2 was 250 ns.

The Influence of Growth Temperature on Oxygen Concentration in GaN Buffer Layer

2008 ◽  
Vol 1068 ◽  
Author(s):  
Ewa Dumiszewska ◽  
Wlodek Strupinski ◽  
Piotr Caban ◽  
Marek Wesolowski ◽  
Dariusz Lenkiewicz ◽  
...  
Keyword(s):  
High Temperature ◽  
Buffer Layer ◽  
Oxygen Concentration ◽  
Growth Temperature ◽  
Low Temperatures ◽  
Buffer Layers ◽  
Crystalline Quality ◽  
Temperature Growth ◽  
Gan Buffer Layer

ABSTRACTThe influence of growth temperature on oxygen incorporation into GaN epitaxial layers was studied. GaN layers deposited at low temperatures were characterized by much higher oxygen concentration than those deposited at high temperature typically used for epitaxial growth. GaN buffer layers (HT GaN) about 1 μm thick were deposited on GaN nucleation layers (NL) with various thicknesses. The influence of NL thickness on crystalline quality and oxygen concentration of HT GaN layers were studied using RBS and SIMS. With increasing thickness of NL the crystalline quality of GaN buffer layers deteriorates and the oxygen concentration increases. It was observed that oxygen atoms incorporated at low temperature in NL diffuse into GaN buffer layer during high temperature growth as a consequence GaN NL is the source for unintentional oxygen doping.

Improvement of Minority Carrier Lifetime in Thick 4H-SiC Epi-layers by Multiple Thermal Oxidations and Anneals

2013 ◽  
Vol 1538 ◽  
pp. 329-333 ◽  
Author(s):  
Lin Cheng ◽  
Michael J. O’Loughlin ◽  
Alexander V. Suvorov ◽  
Edward R. Van Brunt ◽  
Albert A. Burk ◽  
...  
Keyword(s):  
High Temperature ◽  
Carrier Lifetime ◽  
Minority Carrier ◽  
Minority Carrier Lifetime ◽  
Power Devices ◽  
Oxidation Treatment ◽  
Temperature Oxidation ◽  
Oxidation Step ◽  
High Temperature Anneal ◽  
Lifetime Enhancement

ABSTRACTThis paper details the development of a technique to improve the minority carrier lifetime of 4H-SiC thick (≥ 100 μm) n-type epitaxial layers through multiple thermal oxidations. A steady improvement in lifetime is seen with each oxidation step, improving from a starting ambipolar carrier lifetime of 1.09 µs to 11.2 µs after 4 oxidation steps and a high-temperature anneal. This multiple-oxidation lifetime enhancement technique is compared to a single high-temperature oxidation step, and a carbon implantation followed by a high-temperature anneal, which are traditional ways to achieve high ambipolar lifetime in 4H-SiC n-type epilayers. The multiple oxidation treatment resulted in a high minimum carrier lifetime of 6 µs, compared to < 2 µs for other treatments. The implications of lifetime enhancement to high-voltage/high-current 4H-SiC power devices are also discussed.

The Heteroepitaxy and Characterization of Inp and GaInP on Silicon for Solar Cell Applications

1990 ◽  
Vol 198 ◽  
Author(s):  
M.M. Al-Jassim ◽  
R.K. Ahrenkiel ◽  
M.W. Wanlass ◽  
J.M. Olson ◽  
S.M. Vernon
Keyword(s):  
Carrier Lifetime ◽  
Minority Carrier ◽  
Defect Density ◽  
Minority Carrier Lifetime ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Si Substrates ◽  
Threading Dislocation Density ◽  
Direct Growth

ABSTRACTInP and GaInP layers were heteroepitaxially grown on (100) Si substrates by atmospheric pressure MOCVD. TEM and photoluminescence (PL) were used to measure the defect density and the minority carrier lifetime in these structures. The direct growth of InP on Si resulted in either polycrystalline or heavily faulted single-crystal layers. The use of GaAs buffer layers in InP/Si structures gave rise to significantly improved morphology and reduced the threading dislocation density. The best InP/Si layers in this study were obtained by using GaAs-GaInAs graded buffers. Additionally, the growth of high quality GaInP on Si was demonstrated. The minority carrier lifetime of 7 ns in these layers is the highest of any III-V/Si semiconductor measured in our laboratory.

Automatic Determination of In-Depth Profiles of Recombination Lifetime in Epitaxial Si Layer with P+-N−-N+ Stripe Test Pattern Diodes

1991 ◽  
Vol 225 ◽  
Author(s):  
Akira Usami ◽  
Yoshimaro Fujii ◽  
Hideki Fujiwara ◽  
Tomiyasu Sone ◽  
Takao Wada
Keyword(s):  
Buffer Layer ◽  
Test Pattern ◽  
Carrier Lifetime ◽  
Minority Carrier ◽  
Minority Carrier Lifetime ◽  
Recombination Lifetime ◽  
Depth Profiles ◽  
Current Voltage ◽  
Photo Response

ABSTRACTRecombination lifetime of a epitaxial layer (epilayer) is automatically measured by using the conductivity modulation technique. A lateral p+-n−-n+ diode test structure on the surface of the epilayer is formed to evaluate the minority carrier lifetime. Depth profiles of the recombination lifetime are obtained from current-voltage curves of a lateral p+-n−-n+ diode and a vertical n+-n−-n+ structure between the substrate and the top surface. We measure the lifetime in epilayers with and without a buffer-layer. In addition, photo-response of photodiodes with and without the buffer-layer is measured. Profiles of the recombination lifetime depend on the thickness of the epilayer but not on the thickness of the buffer-layer. Minority carrier lifetime in the epilayer, and the leakage current and the photo-response of photodiodes are improved by the buffer-layer formation between epilayer and substrate.

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