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Hot-Wall MOCVD for High-Quality Homoepitaxy of GaN : Understanding Nucleation and Design of Growth Strategies

Delgado Carrascon, Rosalia ; Richter, Steffen LU ; Nawaz, Muhammad ; Paskov, Plamen P. and Darakchieva, Vanya LU (2022) In Crystal Growth and Design 22(12). p.7021-7030
Abstract

Thick GaN layers with a low concentration of defects are the key to enable next-generation vertical power electronic devices. Here, we explore hot-wall metalorganic chemical vapor deposition (MOCVD) for the development of GaN homoepitaxy. We propose a new approach to grow high-quality homoepitaxial GaN in N2-rich carrier gas and at a higher supersaturation as compared to heteroepitaxy. We develop a low-temperature GaN as an optimum nucleation scheme based on the evolution and thermal stability of the GaN surface under different gas compositions and temperatures. Analysis in the framework of nucleation theory of homoepitaxial layers simultaneously grown on GaN templates on SiC and on hydride vapor phase epitaxy GaN substrates is... (More)

Thick GaN layers with a low concentration of defects are the key to enable next-generation vertical power electronic devices. Here, we explore hot-wall metalorganic chemical vapor deposition (MOCVD) for the development of GaN homoepitaxy. We propose a new approach to grow high-quality homoepitaxial GaN in N2-rich carrier gas and at a higher supersaturation as compared to heteroepitaxy. We develop a low-temperature GaN as an optimum nucleation scheme based on the evolution and thermal stability of the GaN surface under different gas compositions and temperatures. Analysis in the framework of nucleation theory of homoepitaxial layers simultaneously grown on GaN templates on SiC and on hydride vapor phase epitaxy GaN substrates is presented. We show that residual strain and screw dislocation densities affect GaN nucleation and subsequent growth leading to distinctively different morphologies of GaN homoepitaxial layers grown on GaN templates and native substrates, respectively. The established comprehensive picture provides a guidance for designing strategies for growth conditions optimization in GaN homoepitaxy. GaN with atomically flat and smooth epilayer surfaces with a root-mean-square roughness value as low as 0.049 nm and low background carbon concentration of 5.3 × 1015 cm-3 has been achieved. It is also shown that there is no generation of additional dislocations during homoepitaxial growth. Thus, our results demonstrate the potential of the hot-wall MOCVD technique to deliver high-quality GaN material for vertical power devices.

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author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Crystal Growth and Design
volume
22
issue
12
pages
7021 - 7030
publisher
The American Chemical Society (ACS)
external identifiers
  • scopus:85141715642
ISSN
1528-7483
DOI
10.1021/acs.cgd.2c00683
language
English
LU publication?
yes
id
3fd2bd5f-8920-4f5c-b099-bb3c9898225a
date added to LUP
2022-12-05 15:03:10
date last changed
2023-11-21 13:28:42
@article{3fd2bd5f-8920-4f5c-b099-bb3c9898225a,
  abstract     = {{<p>Thick GaN layers with a low concentration of defects are the key to enable next-generation vertical power electronic devices. Here, we explore hot-wall metalorganic chemical vapor deposition (MOCVD) for the development of GaN homoepitaxy. We propose a new approach to grow high-quality homoepitaxial GaN in N2-rich carrier gas and at a higher supersaturation as compared to heteroepitaxy. We develop a low-temperature GaN as an optimum nucleation scheme based on the evolution and thermal stability of the GaN surface under different gas compositions and temperatures. Analysis in the framework of nucleation theory of homoepitaxial layers simultaneously grown on GaN templates on SiC and on hydride vapor phase epitaxy GaN substrates is presented. We show that residual strain and screw dislocation densities affect GaN nucleation and subsequent growth leading to distinctively different morphologies of GaN homoepitaxial layers grown on GaN templates and native substrates, respectively. The established comprehensive picture provides a guidance for designing strategies for growth conditions optimization in GaN homoepitaxy. GaN with atomically flat and smooth epilayer surfaces with a root-mean-square roughness value as low as 0.049 nm and low background carbon concentration of 5.3 × 1015 cm-3 has been achieved. It is also shown that there is no generation of additional dislocations during homoepitaxial growth. Thus, our results demonstrate the potential of the hot-wall MOCVD technique to deliver high-quality GaN material for vertical power devices.</p>}},
  author       = {{Delgado Carrascon, Rosalia and Richter, Steffen and Nawaz, Muhammad and Paskov, Plamen P. and Darakchieva, Vanya}},
  issn         = {{1528-7483}},
  language     = {{eng}},
  number       = {{12}},
  pages        = {{7021--7030}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{Crystal Growth and Design}},
  title        = {{Hot-Wall MOCVD for High-Quality Homoepitaxy of GaN : Understanding Nucleation and Design of Growth Strategies}},
  url          = {{http://dx.doi.org/10.1021/acs.cgd.2c00683}},
  doi          = {{10.1021/acs.cgd.2c00683}},
  volume       = {{22}},
  year         = {{2022}},
}