scholarly journals Characterization of High Ge Content SiGe Heterostructures and Graded Alloy Layers Using Spectroscopic Ellipsometry

1994 ◽  
Vol 358 ◽  
Author(s):  
A. R. Heyd ◽  
S. A. Alterovitz ◽  
E. T. Croke

ABSTRACTSixGe1–x heterostructures on Si substrates have been widely studied due to the maturity of Si technology. However, work on SixGe1–x heterostructures on Ge substrates has not received much attention. A SixGe1–x: layer on a Si substrate is under compressive strain while SixGe1–x on Ge is under tensile strain; thus the critical points will behave differently. In order to accurately characterize high Ge content SixGe1–x layers the energy shift algorithm, which is used to calculate alloy compositions, has been modified. These results have been used along with variable angle spectroscopic ellipsometry (VASE) measurements to characterize SixGe1–x/Ge superlattices grown on Ge substrates. The results are found to agree closely with high resolution x-ray diffraction measurements made on the same samples.The modified energy shift algorithm also allows the VASE analysis to be upgraded in order to characterize linearly graded layers. In this work VASE has been used to characterize graded SixGe1–x layers in terms of the total thickness, and the start and end alloy composition. Results are presented for a 1 µm SixGe1–x layer linearly graded in the range 0.5 ≤ x ≤ 1.0.

2005 ◽  
Vol 891 ◽  
Author(s):  
Tomohiko Takeuchi ◽  
Suzuka Nishimura ◽  
Tomoyuki Sakuma ◽  
Satoru Matumoto ◽  
Kazutaka Terashima

ABSTRACTBoronmonophosphide(BP) is one of the suitable materials for a buffer layer between the c-GaN(100) and Si(100) substrates. The growth of BP layer was carried out by MOCVD on Si(100) substrate of 2 inch in diameter. The growth rate was over 2 μm/h without any troubles such as the bowing or cracking. In addition, the thickness of BP epitaxial layer was uniform over a wide area. A careful analysis of x-ray diffraction suggested that the growth of BP epitaxial layer inherited the crystal orientation from Si(100) substrate. Cross-sectional TEM images showed some defects like dislocations near the interface between BP layer and Si substrate. The Hall effect measurements indicated that the conduction type of BP films grown on the both n-Si and p-Si substrates was n-type without impurity doping, and that the mobility and carrier concentrations were typically 357cm2/Vs and 1.5×1020cm−3(on n-Si) and 63cm2/Vs and 1.9×1019cm−3(on p-Si), respectively. In addition, c-GaN was grown on the substrate of BP/Si(100) by RF-MBE.


1986 ◽  
Vol 69 ◽  
Author(s):  
F. Cembali ◽  
A. M. Mazzone ◽  
M. Servidori

The widespread use of through-oxide implants in Si-MOS technology has prompted many studies to characterize the behaviour of oxygen recoiling from the passivating SiO2 layer into the Si substrate. These studies have given support for the idea that an anomalous formation of defects, which alter the profile of the implanted impurity and the mobility of the free carriers, is connected with the oxygen recoils.


2007 ◽  
Vol 22 (5) ◽  
pp. 1214-1218 ◽  
Author(s):  
Hong-Liang Lu ◽  
Min Xu ◽  
Shi-Jin Ding ◽  
Wei Chen ◽  
David Wei Zhang ◽  
...  

Al2O3 films are grown by atomic layer deposition (ALD) using trimethylaluminum and water as precursors on HF-last and NH3 plasma pretreatment Si substrates. The thickness, surface roughness, and density of Al2O3 films as well as the nature of their interlayers with Si substrates are characterized by x-ray reflectivity and spectroscopic ellipsometry techniques. The growth rates of Al2O3 films are 1.1 Å/cycle and 1.3 Å/cycle, respectively, on HF-last and NH3-plasma-nitrided surfaces. Al2O3 layer densities are rather independent of the number of growth cycles in all cases. The interfacial film thickness increases with the number of ALD cycles when deposited on an HF-last Si substrate. However, because SiOxNy inhibits oxygen diffusion, the interfacial film thickness is independent of the number of ALD cycles on the nitrided Si substrate.


1984 ◽  
Vol 41 ◽  
Author(s):  
A. H. Hamdi ◽  
M-A. Nicolet ◽  
Y. C. Kao ◽  
M. Tejwani ◽  
K. L. Wang

AbstractX-ray rocking curves and backscattering spectrometry with channeling have been employed to investigate epitaxial CoSi2 films grown on <111> Si substrates. Several preparation techniques were used: sputter cleaning, chemical cleaning, chemical cleaning with subsequent high temperature annealing, and e-gun evaporation on a cold or hot Si substrate, in situ annealing between 550–750°C for 30 min. Best results were obtained with chemical cleaning and pre-annealing at 925°C for 10 min, Co and Si codeposition on a 580'C hot substrate. For such samples, a typical x-ray perpendicular strain is -2.08%, and parallel strain is -0.11%. This parallel strain implies that the growth has been accommodated by dislocations with a spacing of ,∼ 2000 Å. The values of strain are consistent with the published lattice constants of Si and CoSi2 and Poisson's ratio of 0.28. The minimum yield in the channeling spectra of these films is. ∼ 3.6%, which is only slightly higher than that of <111> virgin Si.


1998 ◽  
Vol 83 (1) ◽  
pp. 174-180 ◽  
Author(s):  
Guolin Yu ◽  
Kalaga Murali Krishna ◽  
Chunlin Shao ◽  
Masayoshi Umeno ◽  
Tetsuo Soga ◽  
...  

1985 ◽  
Vol 53 ◽  
Author(s):  
Li Xiqiang ◽  
Zhu Weiwen ◽  
Lin Chenglu ◽  
Wang Weiyuan ◽  
Tsou Shihchang

ABSTRACTThe InP films with thickness of 1-2 µm and resistivity of 10-10−3Ω-cm were sputtered on oxidized Si substrates heated at about 300°C to form as InP SOI. Using X-ray diffraction, ED, TEM, Hall and RBS, we have investigated the grain size, compositions, thermal stability and electrical characteristics of InP SOI before and after CW Ar+ laser recrystallization. The sputtered InP SOI films appear as polycrystalline and its grain size increases with increasing of irradiated laser power from 5.8 to 7.0 W at a beam diameter of 70 µm. After irradiation at 7 W the single crystal ED patterns are obtained, the mobility and carrier concentrations amount to 103cm2/Vs and 1017cm−3, respectively, and the compositions are stoichiometric.


2002 ◽  
Vol 17 (11) ◽  
pp. 2823-2830 ◽  
Author(s):  
M. Cirakoglu ◽  
S. Bhaduri ◽  
S. B. Bhaduri

Single as well as graded compositions were fabricated in the Ti–B system using a microwave-activated combustion synthesis (MACS) process. When synergistically combined with microwave processing, combustion synthesis offers great potential for the fabrication of ceramic structures and composites. Combustion waves were triggered using a SiC susceptor to initially absorb microwaves. The effects of processing variables, such as thermal insulation, and atmosphere on the process were investigated. Examination of reacted samples by means of x-ray diffraction indicated the presence of titanium monoboride and diboride along with unreacted titanium. Compared with conventional combustion synthesized products, MACS resulted in smaller pores. However, the total amount of porosity remained almost the same. The microstructure of the graded layers and interfaces were examined using optical and scanning electron microscopy. Over the entire cross section, the interfaces were continuous and crack free.


2010 ◽  
Vol 09 (06) ◽  
pp. 549-552
Author(s):  
AYACHE RACHID ◽  
BOUABELLOU ABDERRAHMANE ◽  
EICHHORN FRANK

The processes in the synthesis of a thin layer of hexagonal YSi 2-x phase on a single-crystal Si (111) substrate by implantation of 195 keV Y ions with a dose of 2 × 1017 Y +/ cm 2 at 300°C followed by annealing in an N2 atmosphere at different temperatures for 1 h are investigated. The characterization of the as-implanted and annealed samples is performed using Rutherford backscattering spectrometry (RBS) and X-ray diffraction (XRD) pole figures. Scanning electron microscopy (SEM) was used to view the surface topography. The results show that the orientation relationship between the YSi 2-x layer and Si substrate is YSi 2-x(0001)// Si (111) and YSi 2-x[11–20]// Si [110].


1986 ◽  
Vol 82 ◽  
Author(s):  
D.K. Bowen ◽  
M.J. Hill ◽  
B.K. Tanner

ABSTRACTThe application of double crystal X-ray diffractometry and computer simulation to the characterization of lattice parameter variations through the thickness of heteroepitaxial layers is reviewed. The sensitivity is demonstrated in studies of graded layers grown by vapour phase epitaxy. Capping layers significantly affect rocking curves from superlattice structures. The use of glancing angle diffraction to characterize thin, low period multilayers is examined.


1991 ◽  
Vol 220 ◽  
Author(s):  
Yasuaki Hirano ◽  
Taroh Inada

Single crystal β-SiC films have been fabricated on (100)Si substrates through a thermal reaction between the substrate and carbon atoms sublimed from a high purity graphite source. The substrate temperature during the deposition ranged from 600 to 1100°C. The film properties were analyzed by RHEED and x-ray diffraction measurements. RBS measurements and TEM observations have also been made to investigate the film properties. The single crystal β-SiC films grow at and above 1000°C on (100) substrates. The activation energy is found to be around 1.1 eV for the crystallization process.


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