Type conversion near thep‐Si substrate surface by growing GaAs on Si substrates

1988 ◽  
Vol 64 (3) ◽  
pp. 1266-1270 ◽  
Author(s):  
Takashi Nishioka ◽  
Yoshio Itoh ◽  
Akio Yamamoto ◽  
Masafumi Yamagichi
Keyword(s):  
Substrate Surface ◽  
Si Substrate ◽  
Type Conversion ◽  
Si Substrates ◽  
Gaas On Si

Formation Mechanism of Epitaxial CoSi2 Films on (001) Si Using Ti-Co Bimetallic Layer Source Materials

1992 ◽  
Vol 280 ◽  
Author(s):  
S. L. Hsia ◽  
T. Y. Tana ◽  
P. L. Smith ◽  
G. E. Mcguire
Keyword(s):  
Film Formation ◽  
Substrate Surface ◽  
Native Oxide ◽  
Formation Processes ◽  
Mechanism Of Formation ◽  
Si Substrate ◽  
Barrier Material ◽  
Si Substrates ◽  
Bimetallic Layer ◽  
Source Materials

ABSTRACTThe mechanism of formation of epitaxial CoSi2 film on (001) Si substrate, produced using sequentially deposited Ti-Co bimetallic layer source materials for which Ti was deposited onto the Si substrates first, has been studied by observing the Co silicide formation processes and structures in samples prepared by isochronal annealing and by isothermal annealing. The results demonstrated that, in leading to epitaxial CoSi2 film formation, Ti has played two roles. It has served as a barrier material to Co atoms and thus preventing Co2Si from forming. More importantly, it has allowed nucleation and growth of epitaxial-CoSi2 to dominate the Co silicide film formation process, apparently because it has served as a cleanser to remove native oxide from the Si substrate surface.

MBE Growth of Epitaxial Calcium Fluoride on Silicon

1985 ◽  
Vol 54 ◽  
Author(s):  
L. J. Schowalter ◽  
R. W. Fathauer
Keyword(s):  
Epitaxial Growth ◽  
Detrimental Effect ◽  
Lattice Structure ◽  
Substrate Surface ◽  
Breakdown Field ◽  
Si Substrate ◽  
Semiconductor Interface ◽  
Mbe Growth ◽  
Si Substrates ◽  
Breakdown Field Strength

ABSTRACTThe growth of an epitaxial insulator such as CaF2. on Si substrates and ita subsequent overgrowth with epitaxial sen iconduct ors have a number of important applications in the electronics industry. In addition, it presents a unique opportunity to study an insulator/semiconductor interface under controlled conditions. We have studied the growth of epitaxial CaF. on Si substrates and their subsequent overgrowth with Si or Ge under various conditions. While epitaxial growth of CaF2, (which has an fee lattice structure as does Si) can be obtained on (100), (110) and (111) oriented Si substrates, the best quality crystal growth and surface morphology is obtained on (111) substrates as the CaF. (111) surface has the lowest free energy. Atomic steps on the original Si substrate surface are shown to have a detrimental effect on the epitaxial growth of CaF2. I-V measurements on the epitaxial (111) films show that the intrinsic breakdown field strength exceeds 2 MV/cm, however, high-field induced ionization can cause thermal breakdown at lower voltages. C-V measurements typically show ∼1012 states/cm in the Si band gap as grown. However, it is possible to reduce this number to less than 10 by annealing procedures after growth.

scholarly journals Influence of Si Substrate Preparation Procedure on Polarity of Self-Assembled GaN Nanowires on Si(111): Kelvin Probe Force Microscopy Studies

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1904
Author(s):  
Marta Sobanska ◽  
Núria Garro ◽  
Kamil Klosek ◽  
Ana Cros ◽  
Zbigniew R. Zytkiewicz
Keyword(s):  
Surface Passivation ◽  
Substrate Surface ◽  
Kelvin Probe Force Microscopy ◽  
Ex Situ ◽  
Si Substrate ◽  
Kelvin Probe ◽  
Force Microscopy ◽  
Si Substrates ◽  
Gan Nanowires ◽  
Mixed Polarity

The growth of GaN nanowires having a polar, wurtzite structure on nonpolar Si substrates raises the issue of GaN nanowire polarity. Depending on the growth procedure, coexistence of nanowires with different polarities inside one ensemble has been reported. Since polarity affects the optical and electronic properties of nanowires, reliable methods for its control are needed. In this work, we use Kelvin probe force microscopy to assess the polarity of GaN nanowires grown by plasma-assisted Molecular Beam Epitaxy on Si(111) substrates. We show that uniformity of the polarity of GaN nanowires critically depends on substrate processing prior to the growth. Nearly 18% of nanowires with reversed polarity (i.e., Ga-polar) were found on the HF-etched substrates with hydrogen surface passivation. Alternative Si substrate treatment steps (RCA etching, Ga-triggered deoxidation) were tested. However, the best results, i.e., purely N-polar ensemble of nanowires, were obtained on Si wafers thermally deoxidized in the growth chamber at ~1000 °C. Interestingly, no mixed polarity was found for GaN nanowires grown under similar conditions on Si(111) substrates with a thin AlOy buffer layer. Our results show that reversal of nanowires’ polarity can be prevented by growing them on a chemically uniform substrate surface, in our case on clean, in situ formed SiNx or ex situ deposited AlOy buffers.

Horizontal Defects Parallel to the Interface in GaN Pyramids

1999 ◽  
Vol 5 (S2) ◽  
pp. 734-735
Author(s):  
Zhigang Mao ◽  
Stuart McKernan ◽  
C. Barry Carte ◽  
Wei Yang ◽  
Scott A. McPherson
Keyword(s):  
Defect Density ◽  
Low Cost ◽  
Substrate Surface ◽  
Optoelectronic Devices ◽  
Limited Information ◽  
Si Substrate ◽  
Si Substrates ◽  
Lateral Overgrowth ◽  
Large Size ◽  
Window Area

The performance of III-V nitride-based microelectronic and optoelectronic devices relates directly to the micro structure of these materials. Selective lateral overgrowth has been exploited to produce GaN heteroepitaxial films with low defect density [1]. Si is a promising substrate due to its low cost, large size, and the potential for the intergration of GaN-based optoelectronic devices with Si-based electronics. It is also possible to produce high-quality GaN material for devices using lateral overgrowth on a Si substrate [2]. At present, only limited information on the defect structure in GaN heteroepitaxial films grown by selective lateral growth is available, especially those grown on Si substrate. Recent work [3] on GaN pyramids grown on (111) Si substrates by this method has shown that in the center, or core, of the GaN pyramid (at and above the window area) dislocations thread through the pyramid nearly perpendicular to the substrate surface and the dislocation density is quite high.

Method of GaAs Growth on Single Crystal Si Substrate

1992 ◽  
Vol 263 ◽  
Author(s):  
Valery V. Dorogan ◽  
V.A. Kosyak ◽  
V.G. Trofim
Keyword(s):  
Growth Rate ◽  
Liquid Phase ◽  
Substrate Surface ◽  
Deposition Process ◽  
Temperature Gradients ◽  
Si Substrate ◽  
Island Growth ◽  
Si Substrates ◽  
Epitaxial Deposition ◽  
Substrate Dissolution

ABSTRACTIn the proposed method space and time temperature gradients are used for GaAs epitaxial deposition on Si substrates from liquid phase. Minimal Si substrate dissolution and preferential GaAs deposition from the liquid phase on Si substrate can be obtained by selecting dissolvents, requiring necessary gradients temperature values and times of active phases interaction. Because of nonuniformities in the etched Si substrate surface act as crystallization centres, the deposition process begins from GaAs island growth. Due to the dominate tangential growth rate, the separate single crystals coalesce into a GaAs monolayer.

Effects of substrate quality and annealing on defect structures at GaAs/Si interfaces

1987 ◽  
Vol 45 ◽  
pp. 340-341
Author(s):  
H. L. Tsai ◽  
J. W. Lee
Keyword(s):  
Growth Process ◽  
Molecular Beam ◽  
Substrate Surface ◽  
Lattice Misfit ◽  
Device Fabrication ◽  
Silicon Substrates ◽  
Defect Structures ◽  
Gaas Film ◽  
Substrate Quality ◽  
Gaas On Si

Growth of GaAs on Si using epitaxial techniques has been receiving considerable attention for its potential application in device fabrication. However, because of the 4% lattice misfit between GaAs and Si, defect generation at the GaAs/Si interface and its propagation to the top portion of the GaAs film occur during the growth process. The performance of a device fabricated in the GaAs-on-Si film can be degraded because of the presence of these defects. This paper describes a HREM study of the effects of both the substrate surface quality and postannealing on the defect propagation and elimination.The silicon substrates used for this work were 3-4 degrees off [100] orientation. GaAs was grown on the silicon substrate by molecular beam epitaxy (MBE).

scholarly journals Surface Texturing of Si with Periodically Arrayed Oblique Nanopillars to Achieve Antireflection

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 380
Author(s):  
Jun-Hyun Kim ◽  
Sanghyun You ◽  
Chang-Koo Kim
Keyword(s):  
Aspect Ratio ◽  
Plasma Etching ◽  
Surface Texturing ◽  
Light Reflection ◽  
Si Substrate ◽  
Weighted Mean ◽  
Optical Reflectance ◽  
Si Substrates ◽  
Aspect Ratios ◽  
Shadowing Effect

Si surfaces were texturized with periodically arrayed oblique nanopillars using slanted plasma etching, and their optical reflectance was measured. The weighted mean reflectance (Rw) of the nanopillar-arrayed Si substrate decreased monotonically with increasing angles of the nanopillars. This may have resulted from the increase in the aspect ratio of the trenches between the nanopillars at oblique angles due to the shadowing effect. When the aspect ratios of the trenches between the nanopillars at 0° (vertical) and 40° (oblique) were equal, the Rw of the Si substrates arrayed with nanopillars at 40° was lower than that at 0°. This study suggests that surface texturing of Si with oblique nanopillars reduces light reflection compared to using a conventional array of vertical nanopillars.

scholarly journals Formation and Evaluation of Silicon Substrate with Highly-Doped Porous Si Layers Formed by Metal-Assisted Chemical Etching

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yijie Li ◽  
Nguyen Van Toan ◽  
Zhuqing Wang ◽  
Khairul Fadzli Bin Samat ◽  
Takahito Ono
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Contact Resistance ◽  
Power Factor ◽  
Chemical Etching ◽  
Porous Si ◽  
Si Substrate ◽  
Si Substrates ◽  
Output Performance ◽  
Metal Assisted Chemical Etching

AbstractPorous silicon (Si) is a low thermal conductivity material, which has high potential for thermoelectric devices. However, low output performance of porous Si hinders the development of thermoelectric performance due to low electrical conductivity. The large contact resistance from nonlinear contact between porous Si and metal is one reason for the reduction of electrical conductivity. In this paper, p- and n-type porous Si were formed on Si substrate by metal-assisted chemical etching. To decrease contact resistance, p- and n-type spin on dopants are employed to dope an impurity element into p- and n-type porous Si surface, respectively. Compared to the Si substrate with undoped porous samples, ohmic contact can be obtained, and the electrical conductivity of doped p- and n-type porous Si can be improved to 1160 and 1390 S/m, respectively. Compared with the Si substrate, the special contact resistances for the doped p- and n-type porous Si layer decreases to 1.35 and 1.16 mΩ/cm2, respectively, by increasing the carrier concentration. However, the increase of the carrier concentration induces the decline of the Seebeck coefficient for p- and n-type Si substrates with doped porous Si samples to 491 and 480 μV/K, respectively. Power factor is related to the Seebeck coefficient and electrical conductivity of thermoelectric material, which is one vital factor that evaluates its output performance. Therefore, even though the Seebeck coefficient values of Si substrates with doped porous Si samples decrease, the doped porous Si layer can improve the power factor compared to undoped samples due to the enhancement of electrical conductivity, which facilitates its development for thermoelectric application.

In Situ Diagnostics of Vuv Laser Cvd of Semiconductor Interfaces by Ftir Spectroscopy and Spectroscopic Ellipsometry

1995 ◽  
Vol 397 ◽  
Author(s):  
M. Barth ◽  
J. Knobloch ◽  
P. Hess
Keyword(s):  
Film Thickness ◽  
Bulk Material ◽  
Substrate Surface ◽  
Cluster Formation ◽  
Interface Layer ◽  
Native Oxide ◽  
Initial Growth ◽  
Difference Spectra ◽  
Si Substrates

ABSTRACTThe growth of high quality amorphous hydrogenated semiconductor films was explored with different in situ spectroscopic methods. Nucleation of ArF laser-induced CVD of a-Ge:H on different substrates was investigated by real time ellipsometry, whereas the F2 laser (157nm) deposition of a-Si:H was monitored by FTIR transmission spectroscopy. The ellipsometric studies reveal a significant influence of the substrate surface on the nucleation stage, which in fact determines the electronic and mechanical properties of the bulk material. Coalescence of initial clusters occurs at a thickness of 16 Å for atomically smooth hydrogen-terminated c-Si substrates, whereas on native oxide covered c-Si substrates the bulk volume void fractions are not reached until 35 Å film thickness. For the first time we present a series of IR transmission spectra with monolayer resolution of the initial growth of a-Si:H. Hereby the film thickness was measured simultaneously using a quartz crystal microbalance with corresponding sensitivity. The results give evidence for cluster formation with a coalescence radius of about 20 Å. Difference spectra calculated for layers at different depths with definite thickness reveal that the hydrogen-rich interface layer stays at the substrate surface and does not move with the surface of the growing film. The decrease of the Urbach energy switching from native oxide to H-terminated substrates suggests a strong influence of the interface morphology on the bulk material quality.

Heteroepitaxial Growth of 3C-SiC on Si (111) Substrate Using AlN as a Buffer Layer

2008 ◽  
Vol 600-603 ◽  
pp. 251-254 ◽  
Author(s):  
Yong Mei Zhao ◽  
Guo Sheng Sun ◽  
Xing Fang Liu ◽  
Jia Ye Li ◽  
Wan Shun Zhao ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Chemical Vapor ◽  
Heteroepitaxial Growth ◽  
Si Substrate ◽  
Si Substrates ◽  
Good Crystallinity ◽  
Aln Film ◽  
Pressure Chemical ◽  
Aln Buffer ◽  
Sic Film

Using AlN as a buffer layer, 3C-SiC film has been grown on Si substrate by low pressure chemical vapor deposition (LPCVD). Firstly growth of AlN thin films on Si substrates under varied V/III ratios at 1100oC was investigated and the (002) preferred orientational growth with good crystallinity was obtained at the V/III ratio of 10000. Annealing at 1300oC indicated the surface morphology and crystallinity stability of AlN film. Secondly the 3C-SiC film was grown on Si substrate with AlN buffer layer. Compared to that without AlN buffer layer, the crystal quality of the 3C-SiC film was improved on the AlN/Si substrate, characterized by X-ray diffraction (XRD) and Raman measurements.

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