Origin of Giant Step Bunching on 4H-SiC (0001) Surfaces

2008 ◽  
Vol 600-603 ◽  
pp. 473-476 ◽  
Author(s):  
Yuuki Ishida ◽  
Tetsuo Takahashi ◽  
Hajime Okumura ◽  
Kazuo Arai ◽  
Sadafumi Yoshida
Keyword(s):  
Epitaxial Growth ◽  
Hydrogen Etching ◽  
Step Bunching ◽  
Giant Step ◽  
Cluster Generation

To elucidate the origin of giant step bunching on 4˚ off-axis 4H-SiC (0001) faces, we carried out hydrogen etching and epitaxial growth under various conditions. We found that giant step bunching occurs during hydrogen etching and epitaxial growth at extremely low or high C/Si ratios, i.e., with an excessive supply of SiH4 or C3H8. From these results, we have proposed that the origins of giant step bunching are asymmetry in the step kinetics in etching and Si or C cluster generation on terraces during growth.

Simulation Studies on Giant Step Bunching in 4H-SiC Epitaxial Growth: Cluster Effect

2014 ◽  
Vol 778-780 ◽  
pp. 183-186 ◽  
Author(s):  
Yuuki Ishida ◽  
Sadafumi Yoshida
Keyword(s):  
Computer Simulation ◽  
Epitaxial Growth ◽  
Threshold Value ◽  
Wavy Surface ◽  
Cluster Effect ◽  
Simulation Studies ◽  
Flux Rate ◽  
Step Bunching ◽  
Giant Step

We have developed the computer simulation including cluster effect and Schwoebel effect and investigated the conditions generating GSB using the simulation. We have demonstrated that the simulation developed can reproduce GSB. We have found for the occurence of GSB that there exists a threshold value of the surplus flux rate of Si-or C-source gases not contributing to growth, which depends on the flux rate of each source gas, namely the boundary between with and without GSB. It is noted that this boundary does not depend on the off-angle of substrates. We have also found the mechanism for explaining the occurrence of wavy surface morphplogy.

Giant step bunching on SrTiO3 thin films grown epitaxially on vicinal MgO (1 0 0) surfaces

2021 ◽  
Vol 570 ◽  
pp. 151266
Author(s):  
Azza Hadj Youssef ◽  
Gitanjali Kolhatkar ◽  
Ifeanyichukwu C. Amaechi ◽  
Rajesh Katoch ◽  
Yoandris González ◽  
...  
Keyword(s):  
Thin Films ◽  
Step Bunching ◽  
Giant Step

4H-SiC Homoepitaxial Growth on Vicinal-Off Angled Si-Face Substrate

2010 ◽  
Vol 645-648 ◽  
pp. 99-102 ◽  
Author(s):  
Kazutoshi Kojima ◽  
Sachiko Ito ◽  
Junji Senzaki ◽  
Hajime Okumura
Keyword(s):  
Surface Morphology ◽  
Epitaxial Growth ◽  
Growth Temperature ◽  
Growth Conditions ◽  
Step Bunching ◽  
Homoepitaxial Growth ◽  
Blocking Voltage ◽  
Basal Plane Dislocation ◽  
Epilayer Surface

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.

Experimental Verification of the Cluster Effect on Giant Step Bunching on 4H-SiC (0001) Surfaces

2010 ◽  
Vol 645-648 ◽  
pp. 543-546 ◽  
Author(s):  
Yuuki Ishida ◽  
Tetsuo Takahashi ◽  
Hajime Okumura ◽  
Kazuo Arai ◽  
Sadafumi Yoshida
Keyword(s):  
Thermal Decomposition ◽  
Chemical Reaction ◽  
Experimental Verification ◽  
Reaction Model ◽  
Carbon Clusters ◽  
Cluster Effect ◽  
Step Bunching ◽  
Giant Step ◽  
Chemical Reaction Model

In this study, we investigated the cluster effect on the occurrence of giant step bunching. We generated carbon clusters on 4H-SiC (0001) surfaces by thermal decomposition of SiC in an Ar atmosphere and controlled the surface concentrations of the clusters by adding H2 gas. We found the boundaries between surfaces with and without giant steps to show Arrhenius-type behavior. This behavior agreed with our predictions deduced from a chemical reaction model that takes the cluster effect into account, suggesting that giant step bunching is attributable to the formation of clusters on SiC.

Simulation Studies on Giant Step Bunching Accompanying Trapezoid-Shape Defects in 4H-SiC Epitaxial Layer

2014 ◽  
Vol 778-780 ◽  
pp. 222-225 ◽  
Author(s):  
Yuuki Ishida ◽  
Sadafumi Yoshida
Keyword(s):  
Epitaxial Layer ◽  
Generation Mechanism ◽  
Simulation Studies ◽  
Step Bunching ◽  
Giant Step

Trapezoid-shape (T-S) defects on epilayer surfaces, which include two kinds of the giant step bunching (GSB), are one of killer defects for MOSFETs. We have investigated the generation mechanism of the two GSBs using "step kinetics simulator" we developed. The simulator has reproduced the behavior of the GSBs. Based on results from the simulation, we have discussed the generation mechanism of the two GSBs.

On the “Step Bunching” Phenomena Observed on Etched and Homoepitaxially Grown 4H Silicon Carbide

2011 ◽  
Vol 679-680 ◽  
pp. 358-361 ◽  
Author(s):  
Massimo Camarda ◽  
Andrea Severino ◽  
Patrick Fiorenza ◽  
Vito Raineri ◽  
S. Scalese ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
High Resolution ◽  
Cross Sectional ◽  
Hydrogen Etching ◽  
Step Bunching ◽  
Electron Microscopies ◽  
Atomic Force ◽  
Transmission Electron ◽  
Surface Morphologies ◽  
Scanning Electron

Using several types of surface analysis (Optical profilometers (OP), Atomic Force Microscopies (AFM), Scanning Electron Microscopies (SEM) and cross-sectional high-resolution Transmission Electron Microscopies (TEM)) we analyze the surface morphologies of misoriented 4H silicon carbide after pre-growth hydrogen etching and homo-epitaxial growths. We observed the characteristic self-ordering of nano-facets on any analyzed surface. This nano-faceting, which should not be confused with step bunching, can be considered as a close-to-equilibrium instability, for this reason can be hindered.

Step-Bunching Dependence of the Lifetime of MOS Capacitor on 4o Off-Axis Si-Face 4H-SiC Epitaxial Wafers

2014 ◽  
Vol 778-780 ◽  
pp. 611-614 ◽  
Author(s):  
Akira Bandoh ◽  
Kenji Suzuki ◽  
Yoshihiko Miyasaka ◽  
Hiroshi Osawa ◽  
Takayuki Sato
Keyword(s):  
Epitaxial Growth ◽  
Dielectric Breakdown ◽  
Metal Oxide Semiconductor ◽  
Time Dependent ◽  
Oxide Semiconductor ◽  
Mos Capacitor ◽  
Step Bunching ◽  
Time Dependent Dielectric Breakdown ◽  
Substrate Properties ◽  
Reduced Time

The step-bunching dependence of the lifetime of metal–oxide–semiconductor capacitors on 4° off-axis 4H-SiC epitaxial wafers was investigated. The effects of the C/Si ratios in epitaxial growth and the substrate properties were examined. Step-bunching was observed at the base of triangle or trapezoid defects. Step-bunching decreased as the C/Si ratio was reduced. Time-dependent dielectric breakdown (TDDB) measurements showed that the locations of short lifetime breakdowns closely matched step-bunching positions. TDDB measurements of four different commercial substrates showed clear differences in capacitor lifetime.

Direct Current Heating Induced Giant Step Bunching and Wandering on Si(111) and (001) Vicinal Surfaces

1999 ◽  
Vol 38 (Part 2, No. 3B) ◽  
pp. L308-L311 ◽  
Author(s):  
Masashi Degawa ◽  
Hozumi Nishimura ◽  
Yasumasa Tanishiro ◽  
Hiroki Minoda ◽  
Katsumichi Yagi
Keyword(s):  
Direct Current ◽  
Vicinal Surfaces ◽  
Step Bunching ◽  
Giant Step

Giant step bunching in epitaxial SrRuO3 films on vicinal SrTiO3(001)

2006 ◽  
Vol 495 (1-2) ◽  
pp. 159-164 ◽  
Author(s):  
F. Sánchez ◽  
G. Herranz ◽  
C. Ferrater ◽  
M.V. García-Cuenca ◽  
M. Varela ◽  
...  
Keyword(s):  
Step Bunching ◽  
Giant Step

Homo-Epitaxial Growth on 2° Off-Cut 4H-SiC(0001) Si-Face Substrates Using H2-SiH4-C3H8 CVD System

2014 ◽  
Vol 778-780 ◽  
pp. 214-217 ◽  
Author(s):  
Kentaro Tamura ◽  
Chiaki Kudou ◽  
Keiko Masumoto ◽  
Johji Nishio ◽  
Kazutoshi Kojima
Keyword(s):  
Confocal Microscopy ◽  
Epitaxial Growth ◽  
Carrier Concentration ◽  
Epitaxial Layer ◽  
Defect Density ◽  
Epitaxial Layers ◽  
Differential Interference Contrast ◽  
Step Bunching

We have grown epitaxial layers on 2° off-cut 4H-SiC(0001) Si-face substrates. The epitaxial layer surfaces on 2° off-cut substrates are more prone to generate step-bunching than on 4° off-cut substrates, which are observed by confocal microscopy with differential interference contrast. We have speculated that the step-bunching is generated at the beginning of an epitaxial growth. Triangular defect density of epitaxial layers on 2° off-cut substrates is as low as 0.7 cm–2 for the size corresponding to 150 mm. We have firstly reported distribution of 2° off-cut epitaxial layers for the 150-mm size using two 76.2-mm wafers: σ/mean = 3.3% for thickness, σ/mean = 7.3% for carrier concentration.

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