Defect Reduction of Cvd-Grown Cubic SiC Epitaxial Films on Off-Axis Si(100) Substrates with a Novel Off-Direction.

1990 ◽  
Vol 198 ◽  
Author(s):  
Katsuki Furukawa ◽  
Yoshihisa Fujii ◽  
Akira Suzuki ◽  
Shigeo Nakajima
Keyword(s):  
Defect Density ◽  
Chemical Vapor ◽  
Epitaxial Films ◽  
Defect Reduction ◽  
Fault Density ◽  
Electrolytic Etching ◽  
Order Of Magnitude ◽  
First Time ◽  
Defect Densities ◽  
Sic Films

ABSTRACTMonocrystalline cubic SiC (β -SiC) thin films with lower defect densities have been epitaxially grown by chemical vapor deposition on off-axis Si (100) substrates with off-directions different from the conventional 〈011〉. Stacking faults of β -SiC films are investigated by the electrolytic etching and SEM observation. The effects of off-direction deviated from 〈011〉 are examined for the first time. The off-angle is fixed at 2 degrees. We find a reduction in defect density with increasing deviation angle θ, of off-direction from [011] toward [011[ (θ = 0 - 45°). The defect density becomes one order of magnitude smaller than that of on-axis (100) substrates. A typical value of the stacking fault density is approximately 6 × 106 cm−2 on the substrate with θ = 30° (film thickness: 24μ m).

Growth and Characterization of InP/GaAs on Soi by Mocvd

1990 ◽  
Vol 198 ◽  
Author(s):  
N.H. Karam ◽  
V. Haven ◽  
S.M. Vernon ◽  
F. Namavar ◽  
N. El-Masry ◽  
...  
Keyword(s):  
Thermal Cycle ◽  
Defect Density ◽  
Photoluminescence Intensity ◽  
Defect Reduction ◽  
Reduction Techniques ◽  
Thermal Cycle Annealing ◽  
Cycle Growth ◽  
Order Of Magnitude ◽  
First Time

ABSTRACTEpitaxial InP films have been successfully deposited on GaAs coated silicon wafers with a buried oxide for the first time by MOCVD. The SOI wafers were prepared using the Separation by IMplantation of Oxygen (SIMOX) process. The quality of InP on SIMOX is comparable to the best of InP on Si deposited in the same reactor. Preliminary results on defect reduction techniques such as Thermal Cycle Growth (TCG) show an order of magnitude increase in the photoluminescence intensity and a factor of five reduction in the defect density. TCG has been found more effective than Thermal Cycle Annealing (TCA) in improving the crystalline perfection and optical properties of the deposited films.

Investigation of the Defect Size and Density in Thin SiON Filmfor Organic Device Encapsulation

2016 ◽  
Vol 2016 (1) ◽  
pp. 000272-000276
Author(s):  
Kunmo Chu ◽  
Ki Deok Bae ◽  
Byong Gwon Song ◽  
Yong Young Park ◽  
Jaekwan Kim ◽  
...  
Keyword(s):  
Defect Density ◽  
Chemical Vapor ◽  
Defect Size ◽  
Intrinsic Defect ◽  
Ni Substrate ◽  
Defect Site ◽  
Defect Sites ◽  
Chemical Vapor Deposited ◽  
Density Values ◽  
Defect Densities

Abstract In this study, thin SiON was grown by plasma enhanced chemical vapor deposited (PECVD) method as a thin-film encapsulation (TFE) layer. For defect visualization, electroplating results in a Cu bump grown at each defect site in the SiON film where electrolytic solution establishes contact with the Ni substrate. It was inferred that the Cu bump density could be representative of the intrinsic defect densities for the SiON film. The defect density values were obtained by monitoring the Cu bumps grown at defect sites in the SiON films and then evaluating the number of densities of the Cu bumps for the corresponding defect densities.At the same time, by analyzing the cross section of the Cu bumps grown on SiON film, a linear relation between the Cu bump diameter and the defect size increase was obtained. We expect that this electroplating method allows for rapid visualization of defect distribution and quality evaluation of TFE layers.

Microstructural and Optical Characterization of GaN Films Grown by PECVD on (0001) Sapphire Substrates

1989 ◽  
Vol 162 ◽  
Author(s):  
T. P. Humphreys ◽  
C. A. Sukow ◽  
R. J. Nemanich ◽  
J. B. Posthill ◽  
R. A. Rudder ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Chemical Vapor ◽  
Optical Characterization ◽  
Epitaxial Films ◽  
Optical And Electrical Properties ◽  
Spectroscopy Data ◽  
Sapphire Substrates ◽  
Cubic Gan ◽  
First Time

ABSTRACTEpitaxial GaN films have been grown by plasma-enhanced chemical vapor deposition (PECVD). The growth procedure utilizes a He gas discharge combined with the down-stream introduction of trimethylgallium (TMGa) and nitrogen. Both cubic [1111 and wurtzitic [0001] GaN epitaxial films have been achieved on (0001) sapphire substrates. Differences in substrate growth temperatures are believed to account for the different observed phases. A comparative study pertaining to the microstructural, optical and electrical properties of the α-GaN and β-GaN heteroepitaxial films is presented. Also reported for the first time is the Raman spectroscopy data for cubic GaN.

scholarly journals The Growth and Doping of Al(As)Sb by Metal-Organic Chemical Vapor Deposition

1996 ◽  
Vol 421 ◽  
Author(s):  
R. M. Biefeld ◽  
A. A. Allerman ◽  
S. R. Kurtz
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Active Regions ◽  
Epitaxial Films ◽  
Organic Chemical ◽  
Order Of Magnitude ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Cladding Layers

AbstractAlSb and AlAsxSb1−x epitaxial films grown by metal-organic chemical vapor deposition were successfully doped p- or n-type using diethylzinc or tetraethyltin, respectively. AlSb films were grown at 500°C and 76 torr using trimethylamine or ethyldimethylamine alane and triethylantimony. We examined the growth of AlAsSb using temperatures of 500 to 600 ° C, pressures of 65 to 630 torr, V/Ill ratios of 1–17, and growth rates of 0.3 to 2.7 μm/hour in a horizontal quartz reactor. SIMS showed C and 0 levels below 2 × 1018 cm−3 and 6×1018 cm−3 respectively for undoped AlSb. Similar levels of O were found in AlAs0.16Sb0.84 films but C levels were an order of magnitude less in undoped and Sn-doped AlAs0.16 Sb0.84 films. Hall measurements of AlAs0.16Sb0.84 showed hole concentrations between l×1017 cm−3 to 5×1018 cm−3 for Zn-doped material and electron concentrations in the low to mid 1018 cm−3 for Sndoped material. We have grown pseudomorphic InAs/InAsSb quantum well active regions on AlAsSb cladding layers. Photoluminescence of these layers has been observed up to 300 K.

Reduction of Surface and PL Defects on n-Type 4H-SiC Epitaxial Films Grown Using a High Speed Wafer Rotation Vertical CVD Tool

2018 ◽  
Vol 924 ◽  
pp. 108-111 ◽  
Author(s):  
Yoshiaki Daigo ◽  
Akio Ishiguro ◽  
Shigeaki Ishii ◽  
Hideki Ito
Keyword(s):  
Buffer Layer ◽  
High Speed ◽  
Surface Defect ◽  
Initial Temperature ◽  
Rotation Speed ◽  
Defect Density ◽  
Epitaxial Films ◽  
Wafer Surface ◽  
Defect Densities ◽  
Drift Layer

4H-SiC homo-epitaxial films were grown using a high speed wafer rotation vertical CVD tool, and effects of wafer rotation speed during initial temperature ramping before epitaxial growth were investigated. Also, the effects of conditions during growth of the highly doped buffer layer on both surface and PL defect densities were investigated. It was found that the wafer rotation speed during the temperature ramping has a large influence on the surface defect density of the films. Especially, triangles generated from small pits were considerably reduced in the samples grown at a higher wafer rotation speed during the temperature ramping. The phenomena could be explained as a result of suppressed interfacial reaction between down-falls (DFs) and the wafer surface. Additionally, it was found that the density of basal plane dislocations (BPDs) on a drift layer is remarkably reduced by adjusting the C/Si ratio during growth of the buffer layer grown prior to the drift layer. By applying higher wafer rotation speed during the temperature ramping and optimizing the C/Si ratio for the growth of the buffer layer, a total defect density of 0.75 cm-2 on the film, which includes DFs, triangles, DF-triangles, stacking faults (SFs) and BPDs, was achieved.

Low Defect Thick Homoepitaxial Layers Grown on 4H-SiC Wafers for 6500 V JBS Devices

2019 ◽  
Vol 954 ◽  
pp. 114-120
Author(s):  
Ying Xi Niu ◽  
Xiao Yan Tang ◽  
Li Xin Tian ◽  
Liu Zheng ◽  
Wen Ting Zhang ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Epitaxial Growth ◽  
Process Optimization ◽  
Vapor Deposition ◽  
Defect Density ◽  
Schottky Diodes ◽  
Chemical Vapor ◽  
Epitaxial Films ◽  
Homoepitaxial Layers

70-um thick homoepitaxial layers with very low defect density were grown on 6-inch 4° off-axis wafers using hot-wall chemical vapor deposition (CVD). Process optimization resulted in reduction of the density of triangular defects from 1.01 cm-2 to 0.14 cm-2. The treatment of wafer (CMP or selection) was essential. The in-situ etch process was optimized prior to the epitaxial growth. Junction Barrier Schottky diodes fabricated on the epitaxial films presented a typical I–V characteristic and a block voltage of 6500 V.

Metastability Under High-Intensity Light of Device-Quality He-Diluted, H2-Diluted and Standard a-Si:H Films Deposited Between 50°C and 350°C

1994 ◽  
Vol 336 ◽  
Author(s):  
P. Morin ◽  
P. Roca i Cabarrocas
Keyword(s):  
High Intensity ◽  
Defect Density ◽  
Red Light ◽  
Rf Power ◽  
Wide Range ◽  
Order Of Magnitude ◽  
Kinetics Of ◽  
Defect Densities ◽  
High Intensity Light

ABSTRACTWe report the results of a study of the metastability under illumination by high intensity red light of device quality a-Si:H thin films deposited using a wide range of deposition conditions. The process variables included substrate temperature, pressure, rf power, and dilution of silane by He or H2. In-situ Monitoring of the sample conductivity and defect density during light-soaking provides the kinetics of the degradation of the electronic properties of the films. We observe equilibration of the photoconductivity and of the defect density. The characteristic time of equilibration τse of the defect density varies by more than an order of magnitude, dividing the samples into two groups: one group with a τse on the order of 103 seconds, the other with a τse on the order of 104 seconds. Low steady state defect densities combined with high ημτ products are observed for “standard” a-Si:H deposited between 100°C and 250°C and He-diluted films deposited above 250°C.

Investigation of Carrot Reduction Effect on 4H-Silicon Carbide Epitaxial Wafers with Optimized Buffer Layer

2017 ◽  
Vol 897 ◽  
pp. 75-78 ◽  
Author(s):  
Yuichiro Mabuchi ◽  
Tatsuya Masuda ◽  
Daisuke Muto ◽  
Kenji Momose ◽  
Hiroshi Osawa
Keyword(s):  
Silicon Carbide ◽  
Buffer Layer ◽  
Defect Density ◽  
Buffer Layers ◽  
Defect Reduction ◽  
Conventional Condition ◽  
Reduction Effect ◽  
Defect Densities ◽  
Condition B

We investigated the carrot-defect reduction effect by optimizing the buffer layers of 4H-Silion Carbide (SiC) epitaxial wafers. The SiC epitaxial wafer with the 0.5 μm-thick optimized condition-B buffer layer show the carrot-defect density of 0.13 cm-2, since that with the conventional-A buffer layer were 0.68 cm-2. Although the average bunching length with the optimized condition-B buffer layer was 7-times longer than those with the conventional condition-A buffer layer, we could reduce the bunching length by applying the optimized condition-B only to the initial 0.05 μm-thick buffer layer. Finally, with the initial 0.05 μm-thick optimized condition-B buffer layers, we could achieve the SiC epitaxial wafers with only half the carrot-defect densities of those with the conventional condition-A buffer layers, while the average bunching lengths were less than 100 μm. With this condition, we could achieve the estimated yield of 90.1% with 4 x 4 mm chips, while that with the conventional condition-A buffer layer was 81.9%.

Effects of Annealing on Structural and Optical Properties of ZnO Nanowires

2014 ◽  
Vol 1675 ◽  
pp. 21-25
Author(s):  
Anas Mazady ◽  
Abdiel Rivera ◽  
Mehdi Anwar
Keyword(s):  
Annealing Temperature ◽  
Defect Density ◽  
Volume Ratio ◽  
Chemical Vapor ◽  
Optical Quality ◽  
Structural And Optical Properties ◽  
Si Substrates ◽  
Higher Temperature ◽  
First Time

ABSTRACTWe report, for the first time, effects of annealing of ZnO NWs grown on p-Si substrates. ZnO NWs are grown using metalorganic chemical vapor deposition (MOCVD) and thermal annealing was performed in situ under nitrogen ambient at different stages of the growth process. Increasing the annealing temperature of the ZnO seed epi-layer from 635 °C to 800 °C does not affect the morphology of the grown NWs. In contrast, annealing the NWs themselves at 800 °C results in a 48% decrease of the surface area to volume ratio of the grown NWs. The optical quality can be improved by annealing the seed layer at a higher temperature of 800 °C, although annealing the NWs themselves does not affect the defect density.

A Novel TEM Technique for Characterizing As-Grown CVD Diamond Films

1991 ◽  
Vol 49 ◽  
pp. 956-957 ◽  
Author(s):  
Z.L. Wang ◽  
J. Bentley ◽  
R.E. Clausing ◽  
L. Heatherly ◽  
L.L. Horton
Keyword(s):  
Diamond Films ◽  
Chemical Vapor ◽  
Growth Direction ◽  
Dark Field ◽  
Growth Surface ◽  
Specimen Preparation ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
First Time ◽  
Microstructural Studies

Microstructural studies by transmission electron microscopy (TEM) of diamond films grown by chemical vapor deposition (CVD) usually involve tedious specimen preparation. This process has been avoided with a technique that is described in this paper. For the first time, thick as-grown diamond films have been examined directly in a conventional TEM without thinning. With this technique, the important microstructures near the growth surface have been characterized. An as-grown diamond film was fractured on a plane containing the growth direction. It took about 5 min to prepare a sample. For TEM examination, the film was tilted about 30-45° (see Fig. 1). Microstructures of the diamond grains on the top edge of the growth face can be characterized directly by transmitted electron bright-field (BF) and dark-field (DF) images and diffraction patterns.

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