Effect of sapphire-substrate thickness on the curvature of thick GaN films grown by hydride vapor phase epitaxy

2007 ◽  
Vol 102 (12) ◽  
pp. 123507 ◽  
Author(s):  
T. Paskova ◽  
L. Becker ◽  
T. Böttcher ◽  
D. Hommel ◽  
P. P. Paskov ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Sapphire Substrate ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy ◽  
Substrate Thickness

Novel in situ self-separation of a 2 in. free-standing m-plane GaN wafer from an m-plane sapphire substrate by HCl chemical reaction etching in hydride vapor-phase epitaxy

CrystEngComm ◽  
2016 ◽  
Vol 18 (40) ◽  
pp. 7690-7695
Author(s):  
Seohwi Woo ◽  
Sangil Lee ◽  
Uiho Choi ◽  
Hyunjae Lee ◽  
Minho Kim ◽  
...  
Keyword(s):  
Chemical Reaction ◽  
Vapor Phase ◽  
Sapphire Substrate ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy ◽  
Free Standing

A 2 in.-diameter free-standing m-plane GaN wafer was fabricated through in situ self-separation from m-plane sapphire using HCl chemical reaction etching (HCRE) in hydride vapor-phase epitaxy (HVPE).

Growth of thick GaN layers on laser-processed sapphire substrate by hydride vapor phase epitaxy

2014 ◽  
Vol 403 ◽  
pp. 38-42 ◽  
Author(s):  
Koji Koyama ◽  
Hideo Aida ◽  
Seong-Woo Kim ◽  
Kenjiro Ikejiri ◽  
Toshiro Doi ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Sapphire Substrate ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy

Growth of AlN layer on patterned sapphire substrate by hydride vapor phase epitaxy

2016 ◽  
Vol 55 (5S) ◽  
pp. 05FC02 ◽  
Author(s):  
Gang Seok Lee ◽  
Chanmi Lee ◽  
Hunsoo Jeon ◽  
Chanbin Lee ◽  
Sung Geun Bae ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Sapphire Substrate ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy ◽  
Patterned Sapphire Substrate

scholarly journals Structural and Stress Properties of AlGaN Epilayers Grown on AlN-Nanopatterned Sapphire Templates by Hydride Vapor Phase Epitaxy

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 704 ◽  
Author(s):  
Chi-Tsung Tasi ◽  
Wei-Kai Wang ◽  
Sin-Liang Ou ◽  
Shih-Yung Huang ◽  
Ray-Hua Horng ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Sapphire Substrate ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy ◽  
Threading Dislocation ◽  
Force Microscopy ◽  
Al Content ◽  
Atomic Force ◽  
Transmission Electron ◽  
Biaxial Tensile Stress

In this paper, we report the epitaxial growth and material characteristics of AlGaN (Al mole fraction of 10%) on an AlN/nanopatterned sapphire substrate (NPSS) template by hydride vapor phase epitaxy (HVPE). The crystalline quality, surface morphology, microstructure, and stress state of the AlGaN/AlN/NPSS epilayers were investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The results indicate that the crystal quality of the AlGaN film could be improved when grown on the AlN/NPSS template. The screw threading dislocation (TD) density was reduced to 1.4 × 109 cm−2 for the AlGaN epilayer grown on the AlN/NPSS template, which was lower than that of the sample grown on a flat c-plane sapphire substrate (6.3 × 109 cm−2). As examined by XRD measurements, the biaxial tensile stress of the AlGaN film was significantly reduced from 1,187 MPa (on AlN/NPSS) to 38.41 MPa (on flat c-plane sapphire). In particular, an increase of the Al content in the overgrown AlGaN layer was confirmed by the TEM observation. This could be due to the relaxation of the in-plane stress through the AlGaN and AlN/NPSS template interface.

The influence of sapphire substrate orientation on crystalline quality of GaN films grown by hydride vapor phase epitaxy

2009 ◽  
Vol 404 (23-24) ◽  
pp. 4919-4921
Author(s):  
Anatolij Govorkov ◽  
Alexsandr Donskov ◽  
Lev Diakonov ◽  
Yulia Kozlova ◽  
Sergej Malahov ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Sapphire Substrate ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy ◽  
Crystalline Quality ◽  
Substrate Orientation

scholarly journals In-Situ Preparation of GaN Sacrificial Layers on Sapphire Substrate in MOVPE Reactor for Self-Separation of the Overgrown GaN Crystal

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1100
Author(s):  
Sepideh Faraji ◽  
Elke Meissner ◽  
Roland Weingärtner ◽  
Sven Besendörfer ◽  
Jochen Friedrich
Keyword(s):  
Vapor Phase ◽  
Sapphire Substrate ◽  
Vapor Phase Epitaxy ◽  
The Self ◽  
Etching Process ◽  
Hydride Vapor Phase Epitaxy ◽  
Etching Parameters ◽  
Gan Crystal

GaN layers on sapphire substrates were prepared by using metal organic vapor phase epitaxy (MOVPE) combined with an in-situ H2 etching process for the purpose of later self-separation of thick GaN crystals produced by hydride vapor phase epitaxy (HVPE) on such substrates. The etching process results in deep pits and long voids that formed on the surface and along the lower interface between GaN and sapphire, respectively. The pits, which were investigated by SEM analysis, can be modified in their aspect ratio and density by controlling the etching parameters. Using a proper set of in-situ etching parameters, a seed layer with internal voids can be prepared, which is suitable for HVPE overgrowth and the self-separation process. The quality of the in-situ-etched seed GaN layer and overgrown GaN crystal were characterized by X-ray diffraction (XRD) and defect selective etching (DSE). With the aid of atomic force microscopy (AFM) in tapping mode, the interface morphology of the separated GaN crystal was analyzed. The crystal quality of the separated HVPE-GaN crystal is comparable to the crystal grown on untreated GaN MOVPE-seed, which did not separate from the sapphire substrate. The introduced technique to promote the crystal separation during the HVPE process has no obvious drawback on the quality of the grown GaN crystals. Using this technique, the self-separation occurs more gently due to a weakened interface between GaN/sapphire. The conventional separation from an untreated seed by pure thermomechanical action results in higher mechanical forces on the crystal and consequently much higher risk of crystal breakage.

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