Enhanced etching of GaN with N2 gas addition during CVD diamond growth

Diamond on GaN materials processing is not straight-forward, as GaN is susceptible to a quasi-pure hydrogen CVD plasma etching. 1%, 3% and 5% N2 gas was gradually added to the H2 gas with fixed 6% CH4 in the recipe to promote the growth of diamond nanocrystals. Different types of microstructures wer...

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Main Authors: Awadesh Kumar Mallik, Giridharan Krishnamurthy, Wen-Ching Shih, Paulius Pobedinskas, Jan D’Haen, Ken Haenen
Format: Article
Language:English
Published: Taylor & Francis Group 2024-12-01
Series:Functional Diamond
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Online Access:http://dx.doi.org/10.1080/26941112.2024.2393817
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author Awadesh Kumar Mallik
Giridharan Krishnamurthy
Wen-Ching Shih
Paulius Pobedinskas
Jan D’Haen
Ken Haenen
author_facet Awadesh Kumar Mallik
Giridharan Krishnamurthy
Wen-Ching Shih
Paulius Pobedinskas
Jan D’Haen
Ken Haenen
author_sort Awadesh Kumar Mallik
collection DOAJ
description Diamond on GaN materials processing is not straight-forward, as GaN is susceptible to a quasi-pure hydrogen CVD plasma etching. 1%, 3% and 5% N2 gas was gradually added to the H2 gas with fixed 6% CH4 in the recipe to promote the growth of diamond nanocrystals. Different types of microstructures were produced, with addition of nitrogen to the precursor gas recipe. Nitrogen gas changes the diamond film microstructure from faceted to spherical grains, with signs of GaN etching. The FWHM of the sp3 carbon Raman peak was calculated to be 6.5 cm−1, when there was no nitrogen gas in the precursor recipe, which deteriorates to a large extent after successive addition of N2. Fourier transform infrared spectroscopy (FTIR) showed a strong presence of the nitrogen related defects (peak positions at 1190 and 1299 cm−1) inside the nanocrystalline diamond (NCD) films grown with N2 addition. GaN layer etching from the base substrate by the CVD plasma was clearly evidenced by energy dispersive X-ray spectra (EDS) of the deposited films. Al elemental EDS peaks from the base sapphire substrate were observed for the films grown with nitrogen addition, but no Ga EDS peaks were detected. X-ray diffraction (XRD) micrographs further supported the enhanced GaN etching phenomenon. The electrical resistivity of the uncoated GaN was initially measured to be 22.2 Ω-cm. However, the resistivity rose to 1.59 × 106 Ω-cm after the nitrogen assisted film deposition; due to the GaN etching - thereby exposing the underlying insulating sapphire substrate.
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spelling doaj-art-2ed3cdef2d1e484c8481aad05ba731b42025-08-20T03:14:58ZengTaylor & Francis GroupFunctional Diamond2694-11202024-12-014110.1080/26941112.2024.23938172393817Enhanced etching of GaN with N2 gas addition during CVD diamond growthAwadesh Kumar Mallik0Giridharan Krishnamurthy1Wen-Ching Shih2Paulius Pobedinskas3Jan D’Haen4Ken Haenen5Institute for Materials Research (IMO), Hasselt UniversityInstitute for Materials Research (IMO), Hasselt UniversityInstitute for Materials Research (IMO), Hasselt UniversityInstitute for Materials Research (IMO), Hasselt UniversityInstitute for Materials Research (IMO), Hasselt UniversityInstitute for Materials Research (IMO), Hasselt UniversityDiamond on GaN materials processing is not straight-forward, as GaN is susceptible to a quasi-pure hydrogen CVD plasma etching. 1%, 3% and 5% N2 gas was gradually added to the H2 gas with fixed 6% CH4 in the recipe to promote the growth of diamond nanocrystals. Different types of microstructures were produced, with addition of nitrogen to the precursor gas recipe. Nitrogen gas changes the diamond film microstructure from faceted to spherical grains, with signs of GaN etching. The FWHM of the sp3 carbon Raman peak was calculated to be 6.5 cm−1, when there was no nitrogen gas in the precursor recipe, which deteriorates to a large extent after successive addition of N2. Fourier transform infrared spectroscopy (FTIR) showed a strong presence of the nitrogen related defects (peak positions at 1190 and 1299 cm−1) inside the nanocrystalline diamond (NCD) films grown with N2 addition. GaN layer etching from the base substrate by the CVD plasma was clearly evidenced by energy dispersive X-ray spectra (EDS) of the deposited films. Al elemental EDS peaks from the base sapphire substrate were observed for the films grown with nitrogen addition, but no Ga EDS peaks were detected. X-ray diffraction (XRD) micrographs further supported the enhanced GaN etching phenomenon. The electrical resistivity of the uncoated GaN was initially measured to be 22.2 Ω-cm. However, the resistivity rose to 1.59 × 106 Ω-cm after the nitrogen assisted film deposition; due to the GaN etching - thereby exposing the underlying insulating sapphire substrate.http://dx.doi.org/10.1080/26941112.2024.2393817cvdetchingdiamondganmicrostructureproperties
spellingShingle Awadesh Kumar Mallik
Giridharan Krishnamurthy
Wen-Ching Shih
Paulius Pobedinskas
Jan D’Haen
Ken Haenen
Enhanced etching of GaN with N2 gas addition during CVD diamond growth
Functional Diamond
cvd
etching
diamond
gan
microstructure
properties
title Enhanced etching of GaN with N2 gas addition during CVD diamond growth
title_full Enhanced etching of GaN with N2 gas addition during CVD diamond growth
title_fullStr Enhanced etching of GaN with N2 gas addition during CVD diamond growth
title_full_unstemmed Enhanced etching of GaN with N2 gas addition during CVD diamond growth
title_short Enhanced etching of GaN with N2 gas addition during CVD diamond growth
title_sort enhanced etching of gan with n2 gas addition during cvd diamond growth
topic cvd
etching
diamond
gan
microstructure
properties
url http://dx.doi.org/10.1080/26941112.2024.2393817
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AT giridharankrishnamurthy enhancedetchingofganwithn2gasadditionduringcvddiamondgrowth
AT wenchingshih enhancedetchingofganwithn2gasadditionduringcvddiamondgrowth
AT pauliuspobedinskas enhancedetchingofganwithn2gasadditionduringcvddiamondgrowth
AT jandhaen enhancedetchingofganwithn2gasadditionduringcvddiamondgrowth
AT kenhaenen enhancedetchingofganwithn2gasadditionduringcvddiamondgrowth