Effect of Additional Silane on In Situ H2 Etching prior to 4H-SiC Homoepitaxial Growth

2007 ◽  
Vol 556-557 ◽  
pp. 85-88 ◽  
Author(s):  
Kazutoshi Kojima ◽  
Satoshi Kuroda ◽  
Hajime Okumura ◽  
Kazuo Arai

We have investigated the influence of in-situ H2 etching on the surface morphology of the 4H-SiC substrate prior to homoepitaxial growth. In this study, we varied the types of gas atmosphere during in-situ H2 etching; namely, hydrogen (H2) alone, hydrogen-propane (H2+C3H8), and hydrogen-silane (H2+SiH4). We found that in-situ H2 etching using H2 + SiH4 significantly improved the surface morphology of 4H-SiC substrate just after in-situ H2 etching. By adding SiH4, formation of bunched step structure during in-situ H2 etching could be significantly suppressed. In addition, H2 etching using H2 + SiH4 was able to remove scratches by etching a thinner layer than that using H2 alone. We also discussed the in-situ H2 etching mechanism under the additional SiH4 condition.

2010 ◽  
Vol 645-648 ◽  
pp. 99-102 ◽  
Author(s):  
Kazutoshi Kojima ◽  
Sachiko Ito ◽  
Junji Senzaki ◽  
Hajime Okumura

We have carried out detailed investigations of 4H-SiC homoepitaxial growth on vicinal off-angled Si-face substrates. We found that the surface morphology of the substrate just after in-situ H2 etching was also affected by the value of the vicinal-off angle. Growth conditions consisting of a low C/Si ratio and a low growth temperature were effective in suppressing macro step bunching at the grown epilayer surface. We also demonstrated epitaxial growth without step bunching on a 2-inch 4H-SiC Si-face substrate with a vicinal off angle of 0.79o. Ni Schottky barrier diodes fabricated on an as-grown epilayer had a blocking voltage above 1000V and a leakage current of less than 5x10-7A/cm2. We also investigated the propagation of basal plane dislocation from the vicinal off angled substrate into the epitaxial layer.


2013 ◽  
Vol 740-742 ◽  
pp. 157-160 ◽  
Author(s):  
Jawad ul Hassan ◽  
Axel Meyer ◽  
Semih Cakmakyapan ◽  
Ozgur Kazar ◽  
Jan Ingo Flege ◽  
...  

The evolution of SiC surface morphology during graphene growth process has been studied through the comparison of substrate surface step structure after in-situ etching and graphene growth in vacuum. Influence of in-situ substrate surface preparation on the properties of graphene was studied through the comparison of graphene layers on etched and un-etched substrates grown under same conditions.


1989 ◽  
Vol 160 ◽  
Author(s):  
T. L. Lin ◽  
C. W. Nieh

AbstractEpitaxial IrSi3 films have been grown on Si (111) by molecular beam epitaxy (MBE) at temperatures ranging from 630 to 800 °C and by solid phase epitaxy (SPE) at 500 °C. Good surface morphology was observed for IrSi3 layers grown by MBE at temperatures below 680 °C, and an increasing tendency to form islands is noted in samples grown at higher temperatures. Transmission electron microscopy (TEM) analysis reveals that the IrSi3 layers grow epitaxially on Si(111) with three epitaxial modes depending on the growth conditions. For IrSi3 layers grown by MBE at 630 °C, two epitaxial modes were observed with ~ 50% area coverage for each mode. Single mode epitaxial growth was achieved at a higher MBE growth temperature, but with island formation in the IrSi3 layer. A template technique was used with MBE to improve the IrSi3 surface morphology at higher growth temperatures. Furthermore, single-crystal IrSi3 was grown on Si(111) at 500 °C by SPE, with annealing performed in-situ in a TEM chamber.


1992 ◽  
Author(s):  
Mark R. Kozlowski ◽  
Michael C. Staggs ◽  
Mehdi Balooch ◽  
Robert J. Tench ◽  
Wigbert J. Siekhaus

1989 ◽  
Vol 7 (1) ◽  
pp. 21-26 ◽  
Author(s):  
W. K. Leung ◽  
Y. Hirooka ◽  
R. W. Conn ◽  
D. M. Goebel ◽  
B. Labombard ◽  
...  

2021 ◽  
Vol 63 (7) ◽  
pp. 630-638
Author(s):  
Mustafa Kaptanoglu ◽  
Mehmet Eroglu

Abstract In the study for this contribution, production of in situ synthesized TiB2 particles in iron-based composite coatings using four different submerged arc welding powders (fluxes) containing increasing amounts of ferrotitanium and ferroboron with S1 welding wire, were targeted. For this purpose, coating deposition was carried out to improve the hardness and wear properties of the AISI 1020 steel surfaces using hybrid submerged arc welding. In hybrid submerged arc welding, the welding pool is protected by both welding powders and an argon gas atmosphere. To examine the composite coatings, visual, chemical, microstructural analyses and hardness and wear tests were carried out. With the use of increasing amounts of ferrotitanium and ferroboron in the welding powders, it was observed that the microstructure of the coatings changed in terms of TiB2 particle geometries such as rectangular and hexagonal; volume fractions of TiB2 particles in the coating microstructures increased; hardness values of coatings were enhanced from 34 HRC to 41 HRC; the wear resistance of the coatings improved, and worn surface images of the coatings caused by the counter body changed from continuous with deep scratches to discontinuous with fine scratches and crater cavities.


1995 ◽  
Vol 413 ◽  
Author(s):  
V. Shivshankar ◽  
C. Sung ◽  
J. Kumar ◽  
S. K. Tripathy ◽  
D. J. Sandman

ABSTRACTWe have studied the surface morphology of free standing single crystals of thermochromic polydiacetylenes (PDAs), namely, ETCD and IPUDO (respectively, the ethyl and isopropyl urethanes of 5,7-dodecadiyn-1,12-diol), by Atomic Force Microscopy (AFM) under ambient conditions. Micron scale as well as molecularly resolved images were obtained. The micron scale images indicate a variable surface, and the molecularly resolved images show a well defined 2-D lattice that is interpreted in terms of molecular models and known crystallographic data. Thereby information about surface morphology, which is crucial to potential optical device or chromic sensor performance is available. We also report the observation of a “macroscopic shattering” of the IPUDO monomer crystal during in-situ UV polymerization studies.


2009 ◽  
Vol 615-617 ◽  
pp. 113-116 ◽  
Author(s):  
Kazutoshi Kojima ◽  
Hajime Okumura ◽  
Kazuo Arai

We have carried out detailed investigations on the influence of the growth conditions and the wafer off angle on the surface morphology of low off angle homoepitaxial growth. We found triangular features to be also serious problems on a 4 degree off 4H-SiC Si-face epitaxial layer surface. The control of the C/Si ratio by controlling the SiH4 flow rate is effective in suppressing the triangular features on 4 degree off Si-face homoepitaxial layer. As regards epitaxial growth on a vicinal off-axis substrate, the small off angle difference of a tenth part of a degree has an influence on the surface morphology of the epitaxial layer. This tendency depends on the face polarity and a C-face can be obtained that has a specular surface with a lower vicinal off angle than a Si-face. By controlling this off angle, a specular surface morphology without a bunched step structure could be obtained on a vicinal off angle 4H-SiC Si-face.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5964
Author(s):  
Guoqing Shao ◽  
Juan Wang ◽  
Shumiao Zhang ◽  
Yanfeng Wang ◽  
Wei Wang ◽  
...  

Homoepitaxial growth of step-flow single crystal diamond was performed by microwave plasma chemical vapor deposition system on high-pressure high-temperature diamond substrate. A coarse surface morphology with isolated particles was firstly deposited on diamond substrate as an interlayer under hillock growth model. Then, the growth model was changed to step-flow growth model for growing step-flow single crystal diamond layer on this hillock interlayer. Furthermore, the surface morphology evolution, cross-section and surface microstructure, and crystal quality of grown diamond were evaluated by scanning electron microscopy, high-resolution transmission electron microcopy, and Raman and photoluminescence spectroscopy. It was found that the surface morphology varied with deposition time under step-flow growth parameters. The cross-section topography exhibited obvious inhomogeneity in crystal structure. Additionally, the diamond growth mechanism from the microscopic point of view was revealed to illustrate the morphological and structural evolution.


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