Rapid Thermal Oxidation of GeSi Strained Layers

1990 ◽  
Vol 198 ◽  
Author(s):  
D. K. Nayak ◽  
K. Kamjoo ◽  
J. S. Park ◽  
J. C. S. Woo ◽  
K. L. Wang
Keyword(s):  
Oxidation Rate ◽  
Level Density ◽  
Interface Trap ◽  
Trap Level ◽  
Cold Wall ◽  
Strained Layers ◽  
Oxide Charge ◽  
Si Substrates ◽  
Capacitance Voltage ◽  
Gesi Layer

ABSTRACTA cold-wall rapid thermal processor is used for the oxidation of commensurately grown GexSi1−x layers on Si substrates. It is shown for dry oxidation that the oxidation rate of GeSi is the same as that of Si. The dry oxidationrate of GeSi is independent of Ge concentration (up to 20 % considered in this study) in the GeSi layer. For wet oxidation, however, the rate of oxidation of the GexSi1−x layer is found to be significantly higher than that of pure Si, and the oxidation rate increases with the Ge concentration in GexSi1−x layer. Employing highfrequency and quasistatic Capacitance-Voltage measurements, it is found for a thin oxide that a fixed negative oxide charge density in the range of 1011 – 1012/cm2, and the interface trap level density (in the mid-gap region) of about 1012 /cm2.eV are present. Further, the density of this fixed oxide charge at the SiO2 /GeSi interface is found.to increase with the Ge concentration in the commensurately grown GeSi layers.

Confinement of Threading Dislocations in Simox with a GeSi Strained Layer

1990 ◽  
Vol 198 ◽  
Author(s):  
F. Namavar ◽  
E. Cortesi ◽  
D.L. Perry ◽  
E.A. Johnson ◽  
N.M. Kalkhoran ◽  
...  
Keyword(s):  
Alloy Layer ◽  
Threading Dislocations ◽  
Misfit Dislocations ◽  
Epitaxial Silicon ◽  
Strained Layers ◽  
Strained Layer ◽  
Si Substrates ◽  
Plane View ◽  
Gesi Layer

ABSTRACTWe have investigated improving the crystalline quality of epitaxial silicon grown on SIMOX by confining threading dislocations in the original Si top layer using a GeSi strained layer. Epitaxial Si/GeSi/Si structures were grown by CVD on SIMOX and Si substrates with a GeSi alloy layer about 1000 − 1500 angstroms thick with Ge concentrations of about 0−20%. A Ge concentration in the alloy layer of about 5.5% or higher appears to be necessary in order to bend any of the threading dislocations from the original SIMOX top layer. For a higher Ge concentration of about 16%, most of the threading dislocations appear to be bent and confined by the GeSi layer. In addition, the GeSi strained layers grown by CVD (at about 1000°C) appear to be high quality and no misfit dislocations were observed in the regions studied by XTEM and plane view TEM.

The Research of Trap Level Distribution of PI/AlN (Treated)-MMT Films with Different Contents Based on Decay Charge Theory

2014 ◽  
Vol 981 ◽  
pp. 855-858
Author(s):  
Yuan Yuan Liu ◽  
Jing Hua Yin ◽  
Yao Lei
Keyword(s):  
Distribution Function ◽  
Energy Level ◽  
Discharge Current ◽  
Level Density ◽  
Experimental Results ◽  
Interface Trap ◽  
Trap Level ◽  
Surface Trap ◽  
Trap Energy ◽  
Charge Decay

Through the theoretical deviation based on charge decay theory a trap level distribution function relative to the isothermal discharge current is given in this paper. Based on that, the effect of AlN(treated)-MMT nanoparticles with different contents of 1wt%, 3wt%, 5wt% on surface trap level distribution is researched. The experimental results show that the trap level density is significantly increased compared with traditional IDC and TSC methods. Trap level density and the number of trap charges increase due to the doping AlN (treated)-MMT nanoparticles, and increase with doping contents. The maximum trap energy level density of AlN(treated)-MMT film with 5wt% is 9.14×1024/(eV·m3), which is 3.3 times compared with the PI film corresponding to the trap level in the range of 1.0~1.1eV. The trap level density is affected by the interface trap effect caused by the AlN(treated)-MMT nanoparticles and different contents.

scholarly journals A Study of a-Sic/C-Si(n) Isotype Heterojunctions

1993 ◽  
Vol 16 (1) ◽  
pp. 55-64 ◽  
Author(s):  
N. Georgoulas ◽  
L. Magafas ◽  
A. Thanailakis
Keyword(s):  
Temperature Dependence ◽  
Crystalline Silicon ◽  
Diffusion Mechanism ◽  
Thermionic Emission ◽  
Reverse Current ◽  
Emission Mechanism ◽  
Drift Diffusion ◽  
Si Substrates ◽  
Current Voltage ◽  
Capacitance Voltage

In the present work a study of the electrical properties of heterojunctions between rf sputtered amorphous silicon carbide (a-SiC) thin films and n-type crystalline silicon (c-Si) substrates is reported. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics, as well as the temperature dependence of the current of a-SiC/c-Si(n) heterojunctions were measured. The I-V characteristics of a-SiC/ c-Si(n) heterojunctions exhibit poor rectification properties, with a high reverse current, at higher temperatures (T > 250K), whereas good rectification properties are obtained at lower temperatures (T < 250K). It was found that the a-SiC/c-Si(n) heterojunctions are isotype, suggesting that-the conductivity of a-SiC is n-type. The temperature dependence of the current (from 185K to 320K) showed that the majority carriers of c-Si(n) (i.e. electrons) are transported from c-Si(n) to a-SiC mainly by the thermionic emission mechanism, or by the drift-diffusion mechanism. From C-V measurements of a-SiC/c-Si(n) heterojunctions the electron affinity of a-SiC was found to be X1= 4.20 ± 0.04 eV. Finally, the a-SiC/ c-Si(n) isotype heterojunctions are expected to be interesting devices as infrared

Stress Relaxation in Uniquely Oriented SiGe/Si Epitaxial Layers

1999 ◽  
Vol 594 ◽  
Author(s):  
M. E. Ware ◽  
R. J. Nemanich
Keyword(s):  
Stress Relaxation ◽  
Surface Morphology ◽  
Strain Relaxation ◽  
Epitaxial Layers ◽  
Misfit Dislocations ◽  
Strained Layers ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Deposited Films

AbstractThis study explores stress relaxation of epitaxial SiGe layers grown on Si substrates with unique orientations. The crystallographic orientations of the Si substrates used were off-axis from the (001) plane towards the (111) plane by angles, θ = 0, 10, and 22 degrees. We have grown 100nm thick Si(1−x) Ge(x) epitaxial layers with x=0.3 on the Si substrates to examine the relaxation process. The as-deposited films are metastable to the formation of strain relaxing misfit dislocations, and thermal annealing is used to obtain highly relaxed films for comparison. Raman spectroscopy has been used to measure the strain relaxation, and atomic force microscopy has been used to explore the development of surface morphology. The Raman scattering indicated that the strain in the as-deposited films is dependent on the substrate orientation with strained layers grown on Si with 0 and 22 degree orientations while highly relaxed films were grown on the 10 degree substrate. The surface morphology also differed for the substrate orientations. The 10 degree surface is relatively smooth with hut shaped structures oriented at predicted angles relative to the step edges.

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