Characterization of Ge-Doped Homoepitaxial Layers Grown by Chemical Vapor Deposition

2014 ◽  
Vol 778-780 ◽  
pp. 261-264 ◽  
Author(s):  
Tomasz Sledziewski ◽  
Svetlana Beljakowa ◽  
Kassem Alassaad ◽  
Pawel Kwasnicki ◽  
Roxana Arvinte ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Deep Level ◽  
Chemical Vapor ◽  
Extended Defects ◽  
Enhanced Mobility ◽  
Hall Effect Measurements ◽  
Transient Spectroscopy ◽  
Equal Compensation ◽  
Homoepitaxial Layers

We have investigated the electrical properties of n-type 4H-SiC in-situ germanium-doped homoepitaxial layers grown by chemical vapor deposition. Germanium is an isoelectronic impurity and, therefore, not expected to contribute to the conductivity. However, Hall effect measurements taken on samples with and without germanium revealed an enhanced mobility by a factor of ≈2 at T ≈ 55 K in the germanium-doped sample despite equal free electron concentration and equal compensation. Deep level transient spectroscopy (DLTS) measurements taken on germanium-doped samples reveal negative peaks indicating the presence of charged extended defects.

Very Low Deep Level AlxGa1−xAs (x=0.22) Layer Grown by Metalorganic Chemical Vapor Deposition

1995 ◽  
Vol 378 ◽  
Author(s):  
Z. C. Huang ◽  
Bing Yang ◽  
H. K. Chen ◽  
J. C. Chen
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Deep Level ◽  
Chemical Vapor ◽  
Deep Levels ◽  
Se Doping ◽  
Transient Spectroscopy ◽  
Low Selenium ◽  
Metalorganic Chemical

ABSTRACTWe have achieved deep-level-free Al0.22Ga0.78As epitaxial layers using low selenium (Se)-doping (8.4 × l016 cm−3) grown by metalorganic chemical vapor deposition (MOCVD). Deep levels in various Al0.22Ga0.78As layers grown on GaAs substrates were measured by deep level transient spectroscopy (DLTS). We have found that the commonly observed oxygen contamination-related deep levels at EC-0.53 and 0.70 eV and germanium-related level at EC-0.30 eV in MOCVD-grown Al0.22Ga0.78 As can be eliminated by low Se-doping. In addition, a deep hole level located at Ev+0.65 eV was found for the first time in highly Se-doped Al0.22Ga0.78 As epilayers. We suggest that low Se-doping (<2 × 1017 cm−3) produces a passivation effect and then deactivates other deep levels in Al0.22Ga0.78As.

Electrical Characterization of As and [As+Si] doped GaN Grown by Metalorganic Chemical Vapor Deposition

2004 ◽  
Vol 831 ◽  
Author(s):  
M. Ahoujja ◽  
S. Elhamri ◽  
R. Berney ◽  
Y.K. Yeo ◽  
R. L. Hengehold
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Deep Level ◽  
Electrical Characterization ◽  
Chemical Vapor ◽  
Si Doped ◽  
Transient Spectroscopy ◽  
Metalorganic Chemical

ABSTRACTElectrical properties of As, Si, and [As+Si] doped GaN films grown on sapphire substrates by low temperature metalorganic chemical vapor deposition have been investigated using temperature dependent Hall-effect and deep level transient spectroscopy measurements. The Hall measurements from the GaN layers show that the concentration decreases with arsine flow (4, 40, and 400 sccm) at all temperatures. The carrier concentration of the Si-doped GaN, on the other hand, increases with the incorporation of arsine flow. This behavior is attributed to the formation of AsGa antisites which act as double donors. A deep level at around 0.82 eV below the conduction in the band gap of As doped GaN is measured by DLTS and is tentatively assigned to arsenic on gallium antisite.

Deep Electron and Hole Traps in 6H-SiC Bulk Crystals Grown by the Halide Chemical Vapor Deposition

2006 ◽  
Vol 527-529 ◽  
pp. 497-500 ◽  
Author(s):  
Sung Wook Huh ◽  
A.Y. Polyakov ◽  
Hun Jae Chung ◽  
Saurav Nigam ◽  
Marek Skowronski ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Growth Temperature ◽  
Vapor Deposition ◽  
Deep Level ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Bulk Crystals ◽  
Native Defects ◽  
Transient Spectroscopy ◽  
Electron And Hole Traps

Deep electron and hole traps were studied in a series of high purity 6H-SiC single crystals grown by Halide Chemical Vapor Deposition (HCVD) method at various C/Si flow ratios and at temperatures between 2000 oC and 2100 oC. Characterization included Low Temperature Photoluminescence (LTPL), Deep Level Transient Spectroscopy (DLTS), Minority Carrier Transient Spectroscopy (MCTS), and Thermal Admittance Spectroscopy (TAS) measurements. Concentrations of all deep traps were shown to strongly decrease with increased C/Si flow ratio and with increased growth temperature. The results indicate that the majority of deep centers in 6H-SiC crystals grown by HCVD are due to native defects or complexes of native defects promoted by Si-rich growth conditions. The observed growth temperature dependence of residual donor concentration and traps density is explained by increasing the effective C/Si ratio at higher temperatures for the same nominal ratio of C and Si flows.

Deep Levels in Multilayer Structures of Si/Si0.8Ge0.2 Grown by Low-Pressure Chemical Vapor Deposition

2003 ◽  
Vol 799 ◽  
Author(s):  
Yutaka Tokuda ◽  
Kenichi Shirai
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Deep Level ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Deep Levels ◽  
Multilayer Structures ◽  
Pressure Chemical ◽  
Transient Spectroscopy ◽  
A Minor

ABSTRACTDeep levels in multilayer structures of ten periods Si/Si0.8Ge0.2 (16/5 nm) grown by low-pressure chemical vapor deposition have been characterized by deep level transient spectroscopy (DLTS). DLTS measurements reveal one dominant peak (E1) at around 130 K with a minor peak (E2) at around 240 K. The dominant trap E1 (Ec – 0.19 eV) is ascribed to the dislocation-related defect. The increase of the E1 concentration by a factor of 2 to 3 and the change of its energy level to Ec – 0.22 eV are observed with annealing up to 120°C. It is speculated that hydrogen incorporated during growth associates with E1 and the behavior of E1 upon annealing is caused by the release of hydrogen from E1.

Development of Vertical 3×2〞LPCVD System for Fast Epitaxial Growth on 4H-SiC

2012 ◽  
Vol 717-720 ◽  
pp. 105-108 ◽  
Author(s):  
Wan Shun Zhao ◽  
Guo Sheng Sun ◽  
Hai Lei Wu ◽  
Guo Guo Yan ◽  
Liu Zheng ◽  
...  
Keyword(s):  
Growth Rate ◽  
Chemical Vapor Deposition ◽  
Epitaxial Growth ◽  
Vapor Deposition ◽  
Growth Process ◽  
Chemical Vapor ◽  
Low Pressure ◽  
High Quality ◽  
Pressure Chemical ◽  
Homoepitaxial Layers

A vertical 3×2〞low pressure chemical vapor deposition (LPCVD) system has been developed to realize fast epitaxial growth of 4H-SiC. The epitaxial growth process was optimized and it was found that the growth rate increases with increasing C/Si ratio and tends to saturate when C/Si ratio exceeded 1. Mirror-like thick 4H-SiC homoepitaxial layers are obtained at 1500 °C and C/Si ratio of 0.5 with a growth rate of 25 μm/h. The minimum RMS roughness is 0.20 nm and the FWHM of rocking curves of epilayers grown for 1 hour and 2 hours are 26.2 arcsec and 32.4 arcsec, respectively. These results indicate that high-quality thick 4H-SiC epilayers can be grown successfully on the off-orientation 4H-SiC substrates.

Electrical Properties of Undoped 6H- and 4H-SiC Bulk Crystals Grown by Halide Chemical Vapor Deposition

2006 ◽  
Vol 527-529 ◽  
pp. 625-628
Author(s):  
Hun Jae Chung ◽  
Sung Wook Huh ◽  
A.Y. Polyakov ◽  
Saurav Nigam ◽  
Qiang Li ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Boron Concentration ◽  
Secondary Ion Mass Spectrometry ◽  
Nitrogen Concentration ◽  
Chemical Vapor ◽  
Bulk Crystals ◽  
Hall Effect Measurements ◽  
Site Competition ◽  
Secondary Ion

Undoped 6H- and 4H-SiC crystals were grown by Halide Chemical Vapor Deposition (HCVD). Concentrations of impurities were measured by various methods including secondary-ion-mass spectrometry (SIMS). With increasing C/Si ratio, nitrogen concentration decreased and boron concentration increased as expected for the site-competition effect. Hall-effect measurements on 6H-SiC crystals showed that with the increase of C/Si ratio from 0.06 to 0.7, the Fermi level was shifted from Ec-0.14 eV (nitrogen donors) to Ev+0.6 eV (B-related deep centers). Crystals grown with C/Si > 0.36 showed high resistivities between 1053 and 1010 4cm at room temperature. The high resistivities are attributed to close values of the nitrogen and boron concentrations and compensation by deep defects present in low densities.

Properties of the EL2 Level in Organometallic Ga1−xAlxAs

1987 ◽  
Vol 104 ◽  
Author(s):  
A. Ben Cherifa ◽  
R. Azoulay ◽  
G. Guillot
Keyword(s):  
Vapor Deposition ◽  
Deep Level Transient Spectroscopy ◽  
Metalorganic Chemical Vapor Deposition ◽  
Deep Level ◽  
Chemical Vapor ◽  
Electron Trap ◽  
Quenching Effect ◽  
Deep Electron Trap ◽  
Transient Spectroscopy ◽  
First Time

ABSTRACTWe have studied by means of deep level transient spectroscopy and photocapacitance measurements deep electron traps in undoped Ga1−xAlxAs of n-type grown by metalorganic chemical vapor deposition with 0≤x≤ 0.3. A dominant deep electron trap is detected in the series of alloys. Its activation energy is found at EC-0.8 eV in GaAs and it increases with x. Its concentration is found nearly independent of x. For the first time we observed for this level in the Ga1−xAlxAs alloys, the photocapacitance quenching effect typical for the EL2 defect in GaAs thus confirming clearly that EL2 is also created in MOCVD Ga1−xAlxAs.

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