Wide (0001) terrace formation due to step bunching on a vicinal 4H-SiC (0001) epitaxial layer surface

2017 ◽  
Vol 122 (7) ◽  
pp. 075702 ◽  
Author(s):  
Yuki Tabuchi ◽  
Koji Ashida ◽  
Masashi Sonoda ◽  
Tadaaki Kaneko ◽  
Noboru Ohtani ◽  
...  
Keyword(s):  
Epitaxial Layer ◽  
Layer Surface ◽  
Step Bunching

SEM and ECC Imaging Study of Step-Bunched Structure on 4H-SiC Epitaxial Layers

2017 ◽  
Vol 897 ◽  
pp. 205-208
Author(s):  
Yuki Tabuchi ◽  
Masashi Sonoda ◽  
Koji Ashida ◽  
Tadaaki Kaneko ◽  
Noboru Ohtani ◽  
...  
Keyword(s):  
Epitaxial Layer ◽  
Formation Mechanism ◽  
Low Voltage ◽  
Imaging Study ◽  
Layer Surface ◽  
Step Bunching ◽  
Electron Channeling ◽  
Voltage Electron ◽  
Electron Scanning Microscopy ◽  
Atomically Flat

Step bunching on a vicinal 4H-SiC (0001) epitaxial layer surface was investigated using low-voltage electron scanning microscopy (LVSEM) and electron channeling contrast (ECC) imaging. LVSEM observations revealed that the step bunching resulted in the formation of atomically flat wide (~250 nm) terraces on the surface, and the terraces tended to form in pairs. The two terraces in paired terraces often showed the same electron channeling contrast as each other, and the contrast of the two terraces, either bright or dark, appeared to be determined by the orthogonal misorientation of substrates. On the basis of these results, the formation mechanism of the step-bunched structure on a vicinal 4H-SiC (0001) surface is discussed.

Control of the Surface Morphology on Low Off Angled 4H-SiC Homoepitaxal Growth

2009 ◽  
Vol 615-617 ◽  
pp. 113-116 ◽  
Author(s):  
Kazutoshi Kojima ◽  
Hajime Okumura ◽  
Kazuo Arai
Keyword(s):  
Surface Morphology ◽  
Epitaxial Growth ◽  
Epitaxial Layer ◽  
Flow Rate ◽  
Growth Conditions ◽  
Layer Surface ◽  
Specular Surface ◽  
Homoepitaxial Growth ◽  
Angle Difference ◽  
The Face

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.

4H-SiC Epi-Ready Substrate Qualification by Using Mirror Electron Microscope Inspection System

2020 ◽  
Vol 1004 ◽  
pp. 369-375
Author(s):  
Masaki Hasegawa ◽  
Kentaro Ohira ◽  
Noriyuki Kaneoka ◽  
Tomohiko Ogata ◽  
Katsunori Onuki ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Epitaxial Layer ◽  
Basal Plane ◽  
Mechanical Polishing ◽  
Inspection System ◽  
Layer Surface ◽  
Discrete Point ◽  
Surface Polishing ◽  
Point Set ◽  
Crystal Damage

Crystal damage beneath the surface remaining after chemo-mechanical polishing (CMP) and basal plane dislocations (BPDs) of 4H-SiC epi-ready substrates have been inspected by using a mirror electron microscope inspection system non-destructively. Distributions of crystal damage and BPDs as well as their average densities are estimated by acquiring 80-μm square mirror electron images at positions distributed with an equal pitch over a substrate (“Discrete point set inspection”). Although the total inspected area is less than 1% of the entire substrate area, the inspection results for nine commercially available wafers reveal that there are large differences in surface polishing quality and BPD density between them. Evaluation on an epitaxial layer with a thickness of 10 μm grown on one of the inspected substrates indicated that correlation between distribution of the crystal damages on the substrate and that of bunched steps on the epitaxial layer surface.

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.

A quantitative model of epitaxial layers growth from the gas phase with a simultaneous participation of diffusion, adsorption, and chemical reaction

1986 ◽  
Vol 51 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Emerich Erdös ◽  
Jiří Laitner ◽  
Josef Stejskal ◽  
Přemysl Klíma
Keyword(s):  
Growth Rate ◽  
Gas Phase ◽  
Epitaxial Layer ◽  
Chemical Nature ◽  
Quantitative Description ◽  
Physical Nature ◽  
Rate Equations ◽  
Layer Surface ◽  
Active Centre ◽  
Rate Controlling Step

For a quantitative description of the epitaxial growth rate of gallium arsenide, a model has been proposed including two rate controlling steps, namely one step of physical nature and the other one of chemical nature. As the step of physical nature, the diffusion of gaseous components between the gas phase and the epitaxial layer surface has been considered, and from the steps of chemical nature the adsorption of gaseous components on the epitaxial layer surface and a heterogenous surface reaction have been taken into account. According to the kind of the chemical rate controlling step, five mechanisms have been proposed, where a one - centre model was used in all cases, i.e. the idea that the rate controlling step takes place under participation of one active centre. For all the mechanisms considered, the pertaining rate equations have been derived, which were confronted with the experimentally found dependences of the growth rate on partial pressures of components in the feed. The results are discussed both from the view point of plausibility of individual mechanisms and from the point of view of their applicability and of the next research direction.

Starting Point of Step-Bunching Defects on 4H-SiC Si-Face Substrates

2015 ◽  
Vol 821-823 ◽  
pp. 367-370 ◽  
Author(s):  
Kentaro Tamura ◽  
Masayuki Sasaki ◽  
Chiaki Kudou ◽  
Tamotsu Yamashita ◽  
Hideki Sako ◽  
...  
Keyword(s):  
Oxide Layer ◽  
Epitaxial Layer ◽  
Basal Plane ◽  
X Ray ◽  
Step Bunching ◽  
Line Feature ◽  
Starting Point ◽  
Basal Plane Dislocation ◽  
Koh Etching

On 4H-SiC Si-face substrates after H2etching, the defect with “line” feature parallel to a step as “bunched-step line” was observed. Using X-ray topography and KOH etching, we confirmed that the bunched-step line originated from basal plane dislocation (BPD). Use of the substrate with the lowest BPD density will be effective to reduce bunched-step line that would affect oxide layer reliability on an epitaxial layer. However, more detail investigation needs to classify the BPD that would become a starting point of bunched-step line.

HgCdTe Epitaxial Layer Surface Treatment Using Ammonium Sulfide Before Passivation

2019 ◽  
pp. 453-460
Author(s):  
Rachna Manchanda ◽  
Varun Sharma ◽  
Chanchal ◽  
V. K. Singh ◽  
Anshu Goyal ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Epitaxial Layer ◽  
Layer Surface ◽  
Ammonium Sulfide

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.

Monitoring of Substrate and Epilayer Surfaces by Mirror Projection Electron Microscope

2019 ◽  
Vol 963 ◽  
pp. 255-258
Author(s):  
Isaho Kamata ◽  
Kentaro Ohira ◽  
Kenji Kobayashi ◽  
Masaki Hasegawa ◽  
Mitsuyasu Miyata ◽  
...  
Keyword(s):  
Epitaxial Layer ◽  
Flow Direction ◽  
Substrate Surface ◽  
Surface Damage ◽  
Layer Surface ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Surface Damages ◽  
The Relationship

4H-SiC surfaces before and after epitaxial growth (substrate and epitaxial layer surfaces) were investigated by mirror projection electron microscopy (MPJ) and atomic force microscopy (AFM). On the epitaxial layer surface, two types of short-step-bunchings (SSBs) were observed, one of which featured double grooves and protrusion perpendicular to the step-flow direction and the other, a single groove and protrusion. We also investigated the substrate surface and detected features of sub-surface damage and dislocations. These surfaces were compared and the relationship between the SSBs on the epitaxial layer surface and sub-surface damages and dislocations on the substrate surface were discussed.

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