Homoepitaxial growth of β-Ga2O3 by MOVPE on vicinal (100) oriented substrates: Influence of growth parameters

2021 ◽  
Author(s):  
Andreas Popp ◽  
Saud Bin Anooz ◽  
Ta-Shun Chou ◽  
Raimund Grüneberg ◽  
Klaus Irmscher ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Homoepitaxial Growth

Dislocation Conversion and Propagation during Homoepitaxial Growth of 4H-SiC

2010 ◽  
Vol 645-648 ◽  
pp. 299-302 ◽  
Author(s):  
Birgit Kallinger ◽  
Bernd Thomas ◽  
Sebastian Polster ◽  
Patrick Berwian ◽  
Jochen Friedrich
Keyword(s):  
Growth Parameters ◽  
Threading Dislocations ◽  
X Ray ◽  
Homoepitaxial Growth ◽  
Dislocation Type ◽  
Bipolar Diodes ◽  
Edge Dislocations ◽  
Device Operation ◽  
Thick Layers

Basal Plane Dislocations (BPDs) in SiC are thought to cause degradation of bipolar diodes with blocking voltages > 2kV by triggering the formation and expansion of stacking faults during device operation. Hence, low N doped, thick epitaxial layers without BPDs are urgently needed for the realization of long-term stable SiC bipolar diodes. Such epilayers can be achieved if the conversion of the BPD into another harmless dislocation type is supported by proper epitaxial growth parameters and use of vicinal (off-cut) substrates. In this work, the influence of the substrate’s off-cut angle and of the epilayer thickness on BPD density and surface morphology were investigated. The BPD densities of epilayers grown on 2° and 4° off-cut substrates were very low compared to growth on 8° off-axis substrates. X-Ray Topography has proved that all the Threading Dislocations (TD) propagate from the substrate to the epilayer and that BPDs in the substrate convert to Threading Edge Dislocations (TED) in the epilayer, i.e. the dislocation density (DD) of the substrate determines the epilayer’s DD. The conversion of BPDs is supported by the presence of bunched steps as for growth of thick layers on 2° and 4° off-cut substrates.

In-Grown Stacking Faults in SiC-CVD Using Dichlorosilane and Propane as Precursors

2012 ◽  
Vol 717-720 ◽  
pp. 121-124 ◽  
Author(s):  
Hai Zheng Song ◽  
Sabih U. Omar ◽  
Tawhid Rana ◽  
M.V.S. Chandrashekhar ◽  
Tangali S. Sudarshan
Keyword(s):  
Growth Parameters ◽  
Stacking Faults ◽  
Growth Zone ◽  
Emission Peak ◽  
Regular Growth ◽  
Insulation Material ◽  
Graphite Foil ◽  
Growth Pressure ◽  
Temperature Growth ◽  
Homoepitaxial Growth

In-grown stacking faults (IGSFs) were studied in 4H-SiC homoepitaxial growth from a SiH2Cl2-C3H8-H2 system. Most of the IGSFs, start from the epilayer/substrate interface, and exhibit photoluminescence emission peak at 2.58 eV (480 nm) indicating of 8H polytype. The growth parameters, including growth temperature, growth pressure, growth rate, hydrogen etching, et al., varied around the regular growth condition do not show a significant effect on the IGSF generation. Reactor furniture is identified to be a major reason of IGSF formation, especially when the insulation part of the furnace is not completely isolated from the growth zone. Dusting of insulation material is crucial in the formation of IGSFs. When using graphite felt as the insulation material, the IGSF density in the epilayer can be as high at ~104 cm-2. Improvement of the insulation material by using graphite foil reduces the density to 30-100 cm-2. Further reduction of IGSF density to less than 10 cm-2 is achieved by mild pretreatment of the substrate in molten KOH-NaOH eutectic.

Ge Addition during 4H-SiC Epitaxial Growth by CVD: Mechanism of Incorporation

2015 ◽  
Vol 821-823 ◽  
pp. 115-120
Author(s):  
Véronique Soulière ◽  
Kassem Alassaad ◽  
François Cauwet ◽  
Hervé Peyre ◽  
Thomas Kups ◽  
...  
Keyword(s):  
Experimental Study ◽  
Silicon Carbide ◽  
Surface Morphology ◽  
Epitaxial Growth ◽  
Growth Parameters ◽  
Chemical System ◽  
Impurity Incorporation ◽  
Homoepitaxial Growth

In this paper, we will describe a detailed experimental study on the behavior of Ge incorporation into 4H-SiC during its homoepitaxial growth by CVD. Addition of GeH4 precursor to the standard chemical system SiH4 + C3H8 was investigated as a function of various growth parameters. Its effect on surface morphology, layer quality and purity was followed. All these results will allow proposing an exhaustive picture of Ge incorporation mechanism into 4H-SiC with the possible benefits of such impurity incorporation in the silicon carbide lattice.

Advances in 4H-SiC Homoepitaxy for Production and Development of Power Devices

2006 ◽  
Vol 911 ◽  
Author(s):  
Bernd Thomas ◽  
Christian Hecht ◽  
René Stein ◽  
Peter Friedrichs
Keyword(s):  
Growth Parameters ◽  
Power Devices ◽  
Pin Diodes ◽  
Continuous Growth ◽  
As Doping ◽  
Homoepitaxial Growth ◽  
Layer Deposition ◽  
Research Grade ◽  
P Type

AbstractIn this paper we present results of epitaxial layer deposition for production needs using our hot-wall CVD multi-wafer system. This equipment exhibits a capacity of 7x3” wafers per run and can be upgraded to a 6x4” setup. Characteristics of epilayers and reproducibility of the proc-esses are reported. Furthermore, we show recent results of p-type SiC homoepitaxial growth on 3” 4° off-oriented substrates using a single-wafer hot-wall CVD. The dependence of layer prop-erties on growth parameters, doping and thickness uniformity as well as doping memory effects are discussed. For the characterization of epitaxially grown pn-junctions first research grade pin-diodes were fabricated. The p-type emitters were either deposited in the same growth run to-gether with the n-type buffer and drift layers (continuous growth) or the n- and p-layers were grown in two different growth runs (separate growth).

Homoepitaxial growth of high quality thick diamond film with microwave plasma CVD technique

2011 ◽  
Vol 1282 ◽  
Author(s):  
Hong-Xing Wang ◽  
Noritaka Ishigaki ◽  
Toshiki Ohkawa ◽  
Shinichi Kokami ◽  
Hideo Inoue ◽  
...  
Keyword(s):  
Diamond Film ◽  
Microwave Plasma ◽  
Growth Parameters ◽  
Chemical Vapor ◽  
High Quality ◽  
Plasma Chemical Vapor Deposition ◽  
Homoepitaxial Growth ◽  
Diamond Substrate ◽  
Microwave Plasma Cvd

AbstractA growth of high quality thick diamond film has been carried out on high pressure and high temperature diamond substrate by microwave plasma chemical vapor deposition system. First, the effect of growth parameters on the growth film morphologies was investigated, indicating that the diamond film is very sensitive to the growth temperature and input microwave power. Then, sample holders with different geometries were used in our experiment, illustrating that high quality diamond film can be grown by using the sample holder with flat surface. Finally, the characterization of the as grown samples has been carried out.

Investigation of Triangular Defects in 4H-SiC 4° Off Cut (0001) Si Face Epilayers Grown by CVD

2008 ◽  
Vol 600-603 ◽  
pp. 139-142 ◽  
Author(s):  
Amitesh Shrivastava ◽  
Peter G. Muzykov ◽  
B. Pearman ◽  
S. Michael Angel ◽  
Tangali S. Sudarshan
Keyword(s):  
High Temperature ◽  
Growth Condition ◽  
Defect Formation ◽  
Growth Parameters ◽  
Initial Growth ◽  
Homoepitaxial Growth ◽  
Inverted Pyramid

Triangular defects and inverted pyramid type defects formed during homoepitaxial growth on 4H-SiC Si face, 4° off-cut towards [11-20] direction have been investigated. Growth parameters responsible for triangular defect formation were identified and optimized for its reduction in this study. It was found that although the high temperature reduces the density of inverted pyramid type defects, it is not the only remedy for reducing their density and cleanliness of susceptor along with the initial growth condition plays a major role in the formation of these defects.

On-Axis Homoepitaxy on Full 2” 4H-SiC Wafer for High Power Applications

2009 ◽  
Vol 615-617 ◽  
pp. 133-136 ◽  
Author(s):  
Jawad ul Hassan ◽  
Peder Bergman ◽  
Anne Henry ◽  
Pierre Brosselard ◽  
Phillippe Godignon ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Surface Preparation ◽  
Vital Role ◽  
Pure Hydrogen ◽  
Ambient Conditions ◽  
Homoepitaxial Growth ◽  
Voltage Drift ◽  
Before And After ◽  
Sic Wafer

Homoepitaxial growth has been performed on Si-face nominally on-axis 4H-SiC substrates. Special attention was paid to the surface preparation before starting the growth. Si-face polished surfaces were studied after etching under C-rich, Si-rich and under pure hydrogen ambient conditions. In-situ surface preparation, starting growth parameters and growth temperature are found to play a vital role to maintain the polytype stability in the epilayer. High quality epilayers with 100% 4H-SiC were obtained on full 2” wafer. Complete PiN structure was grown and more than 70% of the diodes showed a stable behavior and the forward voltage drift was less than 0.1 V. Also, a comparison of the electroluminescence images of diodes before and after heavy injection of 125 A/cm2 for 30 min did not show any sign of stacking fault formation in the device active region.

Studies of Ge/Si(100) and Observation of Atomic Steps on Si(100) using Biassed Secondary Electron Imaging in a UHV STEM

1990 ◽  
Vol 48 (1) ◽  
pp. 308-309
Author(s):  
Mohan Krishnamurthy ◽  
Jeff S. Drucker ◽  
John A. Venablest
Keyword(s):  
Secondary Electron ◽  
Critical Thickness ◽  
Surface Defects ◽  
Film Growth ◽  
Growth Parameters ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Surface Steps ◽  
Epitaxial Crystal Growth ◽  
Electron Imaging

Secondary Electron Imaging (SEI) has become a useful mode of studying surfaces in SEM[1] and STEM[2,3] instruments. Samples have been biassed (b-SEI) to provide increased sensitivity to topographic and thin film deposits in ultra high vacuum (UHV)-SEM[1,4]; but this has not generally been done in previous STEM studies. The recently developed UHV-STEM ( codenamed MIDAS) at ASU has efficient collection of secondary electrons using a 'parallelizer' and full sample preparation system[5]. Here we report in-situ deposition and annealing studies on the Ge/Si(100) epitaxial system, and the observation of surface steps on vicinal Si(100) using b-SEI under UHV conditions in MIDAS.Epitaxial crystal growth has previously been studied using SEM and SAM based experiments [4]. The influence of surface defects such as steps on epitaxial growth requires study with high spatial resolution, which we report for the Ge/Si(100) system. Ge grows on Si(100) in the Stranski-Krastonov growth mode wherein it forms pseudomorphic layers for the first 3-4 ML (critical thickness) and beyond which it clusters into islands[6]. In the present experiment, Ge was deposited onto clean Si(100) substrates misoriented 1° and 5° toward <110>. This was done using a mini MBE Knudsen cell at base pressure ~ 5×10-11 mbar and at typical rates of 0.1ML/min (1ML =0.14nm). Depositions just above the critical thickness were done for substrates kept at room temperature, 375°C and 525°C. The R T deposits were annealed at 375°C and 525°C for various times. Detailed studies were done of the initial stages of clustering into very fine (∼1nm) Ge islands and their subsequent coarsening and facetting with longer anneals. From the particle size distributions as a function of time and temperature, useful film growth parameters have been obtained. Fig. 1 shows a b-SE image of Ge island size distribution for a R T deposit and anneal at 525°C. Fig.2(a) shows the distribution for a deposition at 375°C and Fig.2(b) shows at a higher magnification a large facetted island of Ge. Fig.3 shows a distribution of very fine islands from a 525°C deposition. A strong contrast is obtained from these islands which are at most a few ML thick and mottled structure can be seen in the background between the islands, especially in Fig.2(a) and Fig.3.

Evaluation of Azadirachtin on Arthrospira plantensis Gomont growth parameters and antioxidant enzymes

2020 ◽  
Vol 56 ◽  
pp. 8
Author(s):  
Hatice Tunca ◽  
Ali Doğru ◽  
Feray Köçkar ◽  
Burçin Önem ◽  
Tuğba Ongun Sevindik
Keyword(s):  
Enzyme Activity ◽  
Growth Parameters ◽  
Arthrospira Platensis ◽  
Proline Content ◽  
Enzyme Analysis ◽  
Free Proline ◽  
Sod Activity ◽  
Pesticide Pollution ◽  
Antioxidant Parameters ◽  
Mda Content

Azadirachtin (Aza) used as insecticide due to inhibiting growth of insects and preventing them from feeding on plants. To understand the effects of contamination of this insecticide on phototrophs, and to determine the responses of these organisms against these insecticides are extremely important in understanding how the ecosystem is affected. In this study, chlorophyll-a amount, OD 560 and antioxidant parameters (total SOD, APX, GR, Proline, MDA and H2O2) were determined in order to understand the effect of Aza on Arthrospira platensis Gomont. Aza was applied between 0–20 μg mL−1 concentrations for 7 days in the study. Enzyme analysis was conducted at the end of the 7th day. There was a statistically significant decrease in the absorbance of OD560 and the chlorophyll-a content in A. platensis cultures exposed to the Aza (0–20 μg mL−1) during 7 days due to the increase in pesticide levels. SOD activity decreased at 8, 16 and 20 μg mL−1 concentrations; GR enzyme activity showed a significant decrease compared to the control at a concentration of 20 μg mL−1. APX activity did not change significantly compared to control. The MDA content increased significantly at 16 and 20 μg mL−1 concentrations. The H2O2 content significantly increased at 12, 16 and 20 μg mL−1 concentrations (p < 0.05) while the free proline content decreased at 4 μg mL−1 concentration (p < 0.05). As a result, regarding the Aza concentrations used in this study may be a step to prevent pesticide pollution in the environment.

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