Improved Resistivity of GaN with Partially Mg-Doped Grown on Si(111) Substrates by MOCVD

2012 ◽  
Vol 442 ◽  
pp. 16-20
Author(s):  
Yong Wang ◽  
Nai Sen Yu ◽  
Ming Li ◽  
Kei May Lau
Keyword(s):  
Surface Morphology ◽  
Buffer Layer ◽  
Chemical Vapor ◽  
High Resistivity ◽  
Organic Chemical ◽  
Good Surface ◽  
Metal Organic ◽  
Dc Current ◽  
Gan Buffer Layer ◽  
Mg Doped

The continuous 1.0 µm GaN epilayers with and without partially Mg-doped were grown on Si (111) substrates by metal organic chemical vapor deposition (MOCVD). The DC current-voltage (I-V), time-of-flying secondary ion mass spectrometer (ToF-SIMS) and atomic force microscope (AFM) measurements were employed for comparison to characterize surface morphology and resistivity of GaN buffer layer with and without partially Mg-doped. The sample of 1.0 µm GaN epilayer with partially Mg-doped shows much higher resistivity than sample without Mg-doped, which indicates the partially Mg doping in 1.0 µm GaN epilayer can effectively increase the resistivity of GaN grown on Si (111) substrates. As a result, the high resistivity GaN buffer layer with good surface morphology is achieved in the partially Mg-doped GaN buffer layer.

Correlation Between Resistivity and Yellow Luminescence Intensity of MOCVD-Grown GaN Layers

2005 ◽  
Vol 892 ◽  
Author(s):  
Akihiro Hinoki ◽  
Yuichi Hiroyama ◽  
Tadayoshi Tsuchiya ◽  
Tomoyuki Yamada ◽  
Masayuki Iwami ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Leakage Current ◽  
Luminescence Intensity ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Clear Correlation ◽  
Yellow Luminescence ◽  
Metal Organic ◽  
Uv Lamp ◽  
Gan Buffer Layer

AbstractFor further improvements in AlGaN/GaN heterojunction field-effect transistor performance (HFET), it is necessary to reduce the leakage current of the GaN buffer layer. We found a correlation between the leakage current and the intensity of the yellow luminescence of GaN layers taken by UV lamp excitation. The GaN layers were grown by metal organic chemical vapor deposition on SiC substrates. When the samples were excited by a UV (365 nm) lamp, visible yellow luminescence was observed. The leakage current of the GaN buffer layer was measured after deposition of ohmic metal contact. We confirmed clear correlation between the leakage current and the luminescence intensity based from result that the samples with the larger leakage current showed the stronger luminescence intensity. This correlation gives us useful information to understand the drain-source leakage current of AlGaN/GaN HFET.

Cathodeluminescence Characterization of AlGaN Film Grown by MOCVD

2010 ◽  
Vol 143-144 ◽  
pp. 966-970
Author(s):  
Lian Jia Wang ◽  
You Zhang Zhu ◽  
Hong Xia Wang ◽  
Ben Li Liu ◽  
Jin She Yuan
Keyword(s):  
Surface Morphology ◽  
Defect Density ◽  
Chemical Vapor ◽  
Hexagonal Structure ◽  
Single Atom ◽  
Luminescence Properties ◽  
Organic Chemical ◽  
Good Surface ◽  
Photo Detectors ◽  
Metal Organic

Recent achievements in III-nitride semiconductor structures growth have allowed ultraviolet (UV) photo-detectors based on these compounds to be well established today. In this article, AlGaN film of 1-μm thickness was grown on Al2O3 substrate by metal-organic chemical vapor deposition (MOCVD). The AFM was used to analyze the surface morphology of the AlGaN film; X-ray diffraction measurements were used to study the quality of the film’ crystal structure; Cathode-ray luminescence(CL) was employed to study the luminescence properties of the AlGaN film. The result shows that there is a single atom layer on the AlGaN film’surface, and it shows that a low-defect-density AlGaN film with good surface morphology and single crystal Hexagonal structure has been obtained. It is found that there is some relationship between the film’crystal structure , dislocations and the luminescence properties . PACS: 73.61.

scholarly journals Plasma-Assisted MOCVD Growth of Non-Polar GaN and AlGaN on Si(111) Substrates Utilizing GaN-AlN Buffer Layer

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 94
Author(s):  
Pepen Arifin ◽  
Heri Sutanto ◽  
Sugianto ◽  
Agus Subagio
Keyword(s):  
Buffer Layer ◽  
Lattice Mismatch ◽  
Critical Role ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Force Microscopy ◽  
Mocvd Growth ◽  
Metal Organic ◽  
Aln Buffer ◽  
Gan Buffer Layer

We report the growth of non-polar GaN and AlGaN films on Si(111) substrates by plasma-assisted metal-organic chemical vapor deposition (PA-MOCVD). Low-temperature growth of GaN or AlN was used as a buffer layer to overcome the lattice mismatch and thermal expansion coefficient between GaN and Si(111) and GaN’s poor wetting on Si(111). As grown, the buffer layer is amorphous, and it crystalizes during annealing to the growth temperature and then serves as a template for the growth of GaN or AlGaN. We used scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD) characterization to investigate the influence of the buffer layer on crystal structure, orientation, and the morphology of GaN. We found that the GaN buffer layer is superior to the AlN buffer layer. The thickness of the GaN buffer layer played a critical role in the crystal quality and plane orientation and in reducing the cracks during the growth of GaN/Si(111) layers. The optimum GaN buffer layer thickness is around 50 nm, and by using the optimized GaN buffer layer, we investigated the growth of AlGaN with varying Al compositions. The morphology of the AlGaN films is flat and homogenous, with less than 1 nm surface roughness, and has preferred orientation in a-axis.

Metal organic chemical vapor deposition of m-plane GaN epi-layer using a three-step approach towards enhanced surface morphology

2018 ◽  
Vol 667 ◽  
pp. 48-54
Author(s):  
Adreen Azman ◽  
Ahmad Shuhaimi ◽  
Al-Zuhairi Omar ◽  
Anas Kamarundzaman ◽  
Muhammad Imran Mustafa Abdul Khudus ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Surface Morphology ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Enhanced Surface

Deep Level Centers in Carbon-Doped High Resistivity GaN

2014 ◽  
Vol 997 ◽  
pp. 492-495
Author(s):  
Huan Cui ◽  
Li Wu Lu ◽  
Ling Sang ◽  
Bai He Chen ◽  
Zhi Wei He ◽  
...  
Keyword(s):  
Deep Level ◽  
Chemical Vapor ◽  
Deep Levels ◽  
Hall Measurement ◽  
High Resistivity ◽  
Organic Chemical ◽  
Carbon Doped ◽  
Metal Organic ◽  
High Level ◽  
Organic Chemical Vapor Deposition

The deep levels of carbon doped high resistivity (HR) GaN samples grown by metal-organic chemical vapor deposition (MOCVD) has been investigated using thermally stimulated current (TSC) spectroscopy and high temperature (HT) Hall measurement. Two different thickness of 100 and 300 nm were used to be compared. It was found that four distinct deep levels by TSC and one deep level by HT Hall measurement were observed in both samples, which means great help for the decrease of leakage current and lifetime limitations of device utilizing the structure. The activation energy of these levels was calculated and their possible origins were also proposed. The low temperature traps, might be related to VN, 0.50 and 0.52eV related to incorporate a high level carbon, 0.57eV related to VGa, 0.59eV related to CGaor NGa, 0.91 and 0.97eV related to interstitial N1.

Microstructural Characterization of GaN Grown on SiC

2019 ◽  
Vol 25 (6) ◽  
pp. 1383-1393
Author(s):  
Sabyasachi Saha ◽  
Deepak Kumar ◽  
Chandan K. Sharma ◽  
Vikash K. Singh ◽  
Samartha Channagiri ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Raman Spectroscopy ◽  
Surface Morphology ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Organic Chemical ◽  
Nucleation Layer ◽  
Transmission Electron ◽  
Vapor Deposition Technique ◽  
Metal Organic

AbstractGaN films have been grown on SiC substrates with an AlN nucleation layer by using a metal organic chemical vapor deposition technique. Micro-cracking of the GaN films has been observed in some of the grown samples. In order to investigate the micro-cracking and microstructure, the samples have been studied using various characterization techniques such as optical microscopy, atomic force microscopy, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy (TEM). The surface morphology of the AlN nucleation layer is related to the stress evolution in subsequent overgrown GaN epilayers. It is determined via TEM evidence that, if the AlN nucleation layer has a rough surface morphology, this leads to tensile stresses in the GaN films, which finally results in cracking. Raman spectroscopy results also suggest this, by showing the existence of considerable tensile residual stress in the AlN nucleation layer. Based on these various observations and results, conclusions or propositions relating to the microstructure are presented.

Sign in / Sign up

Export Citation Format

Share Document