Hertkorn, J. and Brueckner, P. and Thapa, S. B. and Wunderer, T. and Scholz, F. and Feneberg, M. and Thonke, K. (2007) Optimization of nucleation and buffer layer growth for improved GaN quality. JOURNAL OF CRYSTAL GROWTH, 308 (1). pp. 30-36. ISSN 0022-0248,
Full text not available from this repository. (Request a copy)Abstract
By accurately optimizing the growth conditions for an oxygen doped A1N nucleation layer and for the subsequent epitaxial process the crystal quality of our GaN layers could be improved drastically. In X-ray diffraction analyses we observed FWHM values of 39 and 114 arcsec for the symmetric (0 0 4)- and asymmetric (1 1 4)-reflection, respectively. Consequently, the nominally undoped samples showed semi-insulating behavior in Hall measurements. By in situ deposition of a SiN interlayer, the dislocation density could be reduced by more than a factor of 2, reaching a value of 4 x 10(8) cm(-2) as confirmed by transmission electron microscopy and etch pit density counting. Samples with this low dislocation density showed an extremely narrow X-ray FWHM of 71 arcsec for the asymmetric (1 1 4) reflection along with a narrow linewidth of 870 mu eV in photoluminescence (PL) for the donor bound exciton ((DX)-X-0) at a temperature of 10 K. Atomic force microscopy yielded a very low rms roughness value of about 0.14 nm across a 4 mu m(2) scan area. Finally the excellent crystal quality could be confirmed by growing A1GaN/AIN/GaN high electron mobility transistor structures with reverse breakdown voltages >= 1000 V and a very low sheet resistance of 3 30 Omega/square. (C) 2007 Elsevier B.V. All rights reserved.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | EPITAXIAL LATERAL OVERGROWTH; ALGAN/GAN HETEROSTRUCTURES; THREADING DISLOCATIONS; SAPPHIRE SUBSTRATE; ELECTRON-GAS; X-RAY; MOBILITY; SURFACE; GAN/ALGAN; DENSITY; atomic force microscopy; high resolution x-ray diffraction; nucleation; metalorganic vapor phase epitaxy; nitrides; high electron mobility transistors |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Chair Professor Back > Group Josef Zweck |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 01 Dec 2020 09:50 |
| Last Modified: | 01 Dec 2020 09:50 |
| URI: | https://pred.uni-regensburg.de/id/eprint/32138 |
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