Analysis of junctions formed in strained Si/SiGe substrates

2004 ◽  
Vol 809 ◽  
Author(s):  
G. Eneman ◽  
E. Simoen ◽  
A. Lauwers ◽  
R. Lindsay ◽  
P. Verheyen ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Room Temperature ◽  
Defect Density ◽  
Buffer Layers ◽  
Total Thickness ◽  
Strained Si ◽  
Si Substrates ◽  
Magnitude Increase

ABSTRACTJunctions were formed in thin SiGe/strained Si substrates with a thickness of 250-350 nm to assess the effect of different buffer layer parameters (bandgap, dislocations, thickness) on the junction leakage density that can be expected in MOSFET devices. The implantations used are standard well, channel and Highly Doped Drain (HDD) implants. Both p+/n and n+/p junctions were evaluated. The total thickness of the buffer layers was varied to compare the effect of different structural layers on the diode leakage. This investigation shows that the effect of an increased defect density is dominant at room temperature for the strained Si samples, resulting in 4-5 orders of magnitude increase in leakage. However, there is a different gradation in leakage dependence for thick and thin buffer layers, especially at higher temperatures.

Effects of the Sputtering Time of AlN Buffer Layer on the Quality of ZnO Thin Films

2014 ◽  
Vol 881-883 ◽  
pp. 1117-1121 ◽  
Author(s):  
Xiang Min Zhao
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Rf Magnetron Sputtering ◽  
Buffer Layers ◽  
Zno Thin Films ◽  
Zno Films ◽  
Si Substrates ◽  
Atomic Force ◽  
Structure Morphology ◽  
Aln Buffer

ZnO thin films with different thickness (the sputtering time of AlN buffer layers was 0 min, 30 min,60 min, and 90 min, respectively) were prepared on Si substrates using radio frequency (RF) magnetron sputtering system.X-ray diffraction (XRD), atomic force microscope (AFM), Hall measurements setup (Hall) were used to analyze the structure, morphology and electrical properties of ZnO films.The results show that growth are still preferred (002) orientation of ZnO thin films with different sputtering time of AlN buffer layer,and for the better growth of ZnO films, the optimal sputtering time is 60 min.

Monolithic integration of room-temperature cw GaAs/AlGaAs lasers on Si substrates via relaxed graded GeSi buffer layers

2003 ◽  
Vol 93 (1) ◽  
pp. 362-367 ◽  
Author(s):  
Michael E. Groenert ◽  
Christopher W. Leitz ◽  
Arthur J. Pitera ◽  
Vicky Yang ◽  
Harry Lee ◽  
...  
Keyword(s):  
Room Temperature ◽  
Monolithic Integration ◽  
Buffer Layers ◽  
Si Substrates

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.

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.

Growth and properties of epitaxial PbSe on Si(111) and Si(100) without buffer layer

1995 ◽  
Vol 379 ◽  
Author(s):  
P. Müller ◽  
A.N. Tiwari ◽  
H. Zogg
Keyword(s):  
Buffer Layer ◽  
Lattice Mismatch ◽  
Infrared Detector ◽  
Device Fabrication ◽  
Buffer Layers ◽  
Silicon Substrates ◽  
High Quality ◽  
Si Substrates ◽  
Large Lattice ◽  
Large Lattice Mismatch

Narrow gap IV-VI materials like PbS, PbSnSe and PbSnTe are used for infrared detector device fabrication [1,2]. Earlier an intermediate Ila-fluoride buffer layer, which consisted of a BaF2/CaF2-stack of about 2000 Å thickness, was used to get epitaxial high quality layers on silicon substrates. This buffer is now reduced to a much thinner layer of only about 20 Å thick CaF2, regardless the large lattice mismatch between layer and substrate [3,4,5]. The question therefore arises if high quality IV-VI layers can be grown on Si-substrates without any buffer layer as e.g. in CdTe/Si or GaAs/Si systems.The aim of this work is to grow IV-VI layers directly on Si-substrates without any buffer layers to study the growth kinetics and epitaxial quality. PbSe was chosen as a representant of IV-VI materials, and layers were grown on (111)- and (100)-oriented silicon substrates.

The Reduction of The Defect Density in CdTe Buffer Layers for The Growth of HgCdTe Infrared Photodiodes on Si (211) Substrates

1997 ◽  
Vol 484 ◽  
Author(s):  
H.-Y. Wei ◽  
L. Salamanca-Riba ◽  
N. K. Dhar
Keyword(s):  
Dislocation Density ◽  
Defect Density ◽  
Three Dimensional ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Si Substrates ◽  
Migration Enhanced Epitaxy ◽  
Threading Dislocation Density ◽  
Order Of Magnitude ◽  
Cdte Buffer

CdTe epilayers were grown by molecular beam epitaxy on As-passivated nominal (211) Si substrates using thin interfacial ZnTe layers. By using thin recrystallized (initially amorphous) ZnTe buffei layers, we utilized migration enhanced epitaxy (MEE) in the ZnTe layer and overcome the tendency toward three dimensional nucleation. The threading dislocation densities in 8–9 tm thick CdTe films deposited on the recrystallized amorphous ZnTe films were in the range of 2 to 5 × 105 cm−2. In addition to the reduction of threading dislocation density, the interface between the ZnTe layers and the Si substrate is much smoother and the microtwin density is an order of magnitude lower than in regular MEE growth. In order to understand the initial nucleation mechanism of the ZnTe on the As precursor Si surface, we also grew ZnTe epilayers on Te precursor treated Si substrates. The growth mode, microtwin density, and threading dislocation density are compared for films grown on Si substrates with different surface precursors and grown by different growth methods.

Sb Implantation in Si1–xGex/Si(100) Structures

1991 ◽  
Vol 235 ◽  
Author(s):  
Z. Atzmon ◽  
M. Eizenberg ◽  
P. Revesz ◽  
J. W. Mayer ◽  
F. Schäffler
Keyword(s):  
Short Distance ◽  
Room Temperature ◽  
Solid Phase ◽  
Amorphous Layer ◽  
Strained Si ◽  
Si Substrates ◽  
Epitaxial Regrowth ◽  
Heat Treated ◽  
Significant Difference ◽  
Initial Process

ABSTRACTSolid phase epitaxial regrowth of Sb implanted strained Si1−x Gex alloy layers is reported. Two sets of Si1–xGex alloys with compositions of x=0.08 and x=0.18, MBE grown on (100)Si substrates, were implanted at room temperature with Sb− ions at energies of 200 and 100 keV, respectively, and a dose of 1015cm−2. These alloys were heat-treated in a rapid thermal annealing system at temperatures of 525, 550 and 575°C for durations between 5 and 600 sec. The study of the solid phase epitaxial regrowth was performed by Rutherford backscattering in the channeling mode. The measurements show a significant difference in the regrowth mechanism between the two alloys. For the Si0.92Ge0.00 alloy a fast regrowth process (faster than for Sb implanted Si or Si implanted SiGe layers) occured with an activation energy of 2.92±0.2eV. For the Si0.02Ge0.10 alloy the regrowth took place in two steps: a) a very fast initial process over a short distance, b) a regrowth process of the majority of the amorphous layer.

Crystallinity and Photoluminescence Properties of ZnO Films on Zn Buffer Layers Deposited by rf Magnetron Sputtering

2007 ◽  
Vol 336-338 ◽  
pp. 567-570
Author(s):  
Chong Mu Lee ◽  
Anna Park ◽  
Young Joon Cho ◽  
Hyoun Woo Kim ◽  
Jae Gab Lee
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Buffer Layer ◽  
Rf Magnetron Sputtering ◽  
Buffer Layers ◽  
Zno Films ◽  
Zno Thin Film ◽  
Zno Film ◽  
Amorphous Sio2 ◽  
Si Substrates

It is very desirable to grow ZnO epitaxial films on Si substrates since Si wafers with a high quality is available and their prices are quite low. Nevertheless, it is not easy to grow ZnO films epitaxially on Si substrates directly because of formation of an amorphous SiO2 layer at the interface of ZnO and Si. A Zn film and an undoped ZnO film were deposited sequentially on an (100) Si substrate by rf magnetron sputtering. The sample was annealed at 700°C in a nitrogen atmosphere. X-ray diffraction (XRD), photoluminescence (PL) and atomic force microscopy (AFM) analyses were performed to investigate the cristallinity and surface morphology of the ZnO film. According to the analysis results the crystallinity of a ZnO thin film deposited by rf magnetron sputtering is substantially improved by using a Zn buffer layer. The highest ZnO film quality is obtained with a 110nm thick Zn buffer layer. The surface roughness of the ZnO thin film increases as the Zn buffer layer thickness increases.

Electronic Properties of CdTe/CdS Solar Cells as Influenced by a Buffer Layer

MRS Advances ◽  
2016 ◽  
Vol 1 (14) ◽  
pp. 937-942 ◽  
Author(s):  
Y. G. Fedorenko ◽  
J. D. Major ◽  
A. Pressman ◽  
L. Phillips ◽  
K. Durose
Keyword(s):  
Solar Cells ◽  
Grain Boundary ◽  
Electronic Properties ◽  
Buffer Layer ◽  
Defect Density ◽  
Deep Trap ◽  
Energy Shift ◽  
Buffer Layers ◽  
Cdte Solar Cells ◽  
Strain Interaction

ABSTRACTWe considered modification of the defect density of states in CdTe as influenced by a buffer layer in ZnO(ZnS, SnSe)/CdS/CdTe solar cells. Compared to the solar cells employing ZnO buffer layers, implementation of ZnSe and ZnS resulted in the lower net ionized acceptor concentration and the energy shift of the dominant deep trap levels to the midgap of CdTe. The results clearly indicated that the same defect was responsible for the inefficient doping and the formation of recombination centers in CdTe. This observation can be explained taking into account the effect of strain on the electronic properties of the grain boundary interface states in polycrystalline CdTe. In the conditions of strain, interaction of chlorine with the grain boundary point defects can be altered.

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