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.

Arsenic Diffusion and Segregation Behavior at the Interface of Epitaxial CoSi2 Film and Si Substrate

1993 ◽  
Vol 320 ◽  
Author(s):  
S. L. Hsia ◽  
T. Y. Tan ◽  
P. L. Smith ◽  
G. E. Mcguire
Keyword(s):  
Qualitative Agreement ◽  
Film Formation ◽  
Formation Temperature ◽  
Si Substrate ◽  
Free Surfaces ◽  
Si Substrates ◽  
Segregation Behavior ◽  
P Type ◽  
Physical Reasons ◽  
Source Materials

ABSTRACTArsenic diffusion and segregation properties at the interface of the epitaxial CoSi2 and Si substrate have been studied. Samples have been prepared using Co-Ti bimetallic source materials and two types of (001) Si substrates: n+ (doped by As to ∼2}1019 cm−3) and p. For the n+ Si cases, the lower limit of the CoSi2 film formation temperature is increased by ∼200°C to ∼700°C. SIMS results showed As segregation into Si. For epitaxial CoSi2 film formation at 900°C, the As concentration has increased by a factor of ∼2 within a distance of ∼30nm from the interface, while the incorporated As in the film is ∼30-50 times less than that in Si. For p-type Si substrate cases, the epitaxial CoSi2 film was first grown and followed by As+ implantation (into the film) and drive-in processes. It is observed that As was segregated to the CoSi2-Si interface and diffused into Si. This is in qualitative agreement with our results obtained from the n+ substrate experiments and the results of other authors involving the use of polycrystalline CoSi2 films. In the present cases, all implanted As were conserved at a drive in-temperature of 1000°C for up to 100 s. This is in contrast to the polycrystalline CoSi2 film results which involve a substantial As loss to the film free surfaces. The physical reasons of this difference have been discussed.

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.

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.

Arrays of Au Nanoparticles on Si Formed by Nanoindentation and a Simple Thermal/Wipe-Off Technique

2011 ◽  
Vol 700 ◽  
pp. 141-144
Author(s):  
Avi Shalav ◽  
Sherman Wong ◽  
Simon Ruffell ◽  
Robert G. Elliman
Keyword(s):  
Au Nanoparticles ◽  
Inert Atmosphere ◽  
Native Oxide ◽  
Oxide Surface ◽  
Si Nanowires ◽  
Si Substrate ◽  
Si Substrates ◽  
Ordered Arrays ◽  
Native Oxides ◽  
Almost All

This study demonstrates a novel technique for the fabrication of ordered arrays of Au rich nanoparticles on a Si substrate. Si substrates, with their native oxides intact, are pre-patterned using nanoindentation to create regions on the surface that readily alloy at higher temperatures with a thin thermally evaporated Au layer. Larger Au rich particles are observed to form at the indentation sites after high temperature annealing in an inert atmosphere. After mechanical wiping, the Au rich particles lying within the indentation sites remain while almost all the particles on the native oxide surface are readily removed. Using PECVD techniques, multi-prong Si nanowires are shown to grow from the remaining arrays of Au rich particles.

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.

Thin film formation processes controlled by the momentum parallel to the substrate surface

2000 ◽  
Vol 375 (1-2) ◽  
pp. 68-72
Author(s):  
Kozo Obara ◽  
Zixun Fu ◽  
Masahiro Arima
Keyword(s):  
Thin Film ◽  
Film Formation ◽  
Substrate Surface ◽  
Formation Processes ◽  
Thin Film Formation

Ionized Cluster Beam Epitaxy of Single Crystal Metal Films on Semiconductors and Insulators

1987 ◽  
Vol 93 ◽  
Author(s):  
I. Yamada ◽  
L. L. Levenson ◽  
H. Usui ◽  
T. Takagi
Keyword(s):  
Single Crystal ◽  
Film Formation ◽  
Substrate Surface ◽  
Three Dimensional ◽  
Lattice Misfit ◽  
Cluster Ions ◽  
Mis Structure ◽  
Ionic Charge ◽  
Surface And Interface ◽  
Si Substrates

ABSTRACTOur experiments show that ionized cluster beams (ICB) can form epitaxial Al films on Si(111) and Si(100) substrates. This is unique because the lattice misfit of this material combination is more than 25%. Al can also be epitaxially grown on CaF2 films deposited on Si substrates. The initial stage of the film formation is measured by in-situ electron diffraction. In the case of Al(111) growth on Si(111) and CaF2, growth of mixed layers of different epitaxial islands of approximately 20–50 Angstrom thickness on the substrate surface is observed. With increase of thickness, the film shows the single crystal state with a flat surface, which indicates the epitaxial single crystal film formation on CaF2 or on Si substrates. It should be noted that in the Al/CaF2/Si (MIS) structure, the epitaxial CaF2 is a good insulating layer, which can be used to prepare three dimensional devices. These results show that the kinetic energy and the ionic charge of cluster ions have much influence on surface and interface modification, and that ICB is capable of producing films of good quality at low substrate temperatures.

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

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.

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