Optimisation of LT-GaN nucleation layer growth conditions for the improvement of electrical and optical parameters of GaN layers

• Autorzy: Wośko Mateusz

Identyfikatory

DOI

10.5277/oa190115

• Języki publikacji: EN

Abstrakty

EN

In this work we present the influence of low temperature gallium nitride (LT-GaN) nucleation layer deposition and recrystallization conditions on the electrical and optical properties of buffer and active layer of metal–semiconductor field-effect transistor (MESFET) structure. MESFET structures were used to investigate the properties of bulk materials that determine also the performance of many type GaN based devices, like light emitting diodes (LEDs), high electron mobility transistors (HEMTs) and metal–semiconductor–metal (MSM) detectors. The set of n-GaN/u-GaN/sapphire structures using different nucleation LT-GaN layers thickness and different annealing times was deposited using AIXTRON CCS epitaxial system. In contrast to typical procedure, the high resistive GaN buffer layer was not obtained by intentional Fe/Mg doping, but by specific adjustment of GaN nucleation conditions and recrystallization process parameters that introduce carbon atoms in epitaxial layers, that serve as donors. Generally, low pressure (below 200 mbar) in a reactor chamber, during initial stages of nucleation and recrystallization as well as HT-GaN epitaxy, promotes the growth of high resistive material. Obtained results show that annealing/recrystallization time of LT-GaN has a significant impact on the electrical and optical properties of GaN buffer layers. Longer annealing periods tend to promote crystallization of material with higher electron mobility and higher Si dopant incorporation/activation while maintaining high resistivity in u-GaN buffer area. It was shown that the dimensions of the GaN islands, that could be influenced by the duration of an annealing step of LT-GaN growth, have no impact on the HT-GaN buffer layer coalescence process and material resistivity, but influences mainly electrical properties of active n-GaN layer. Author suggests that the key parameters that are determining the buffer resistivity are the pressure and temperature during LT-GaN annealing and buffer layer coalescence. The influence of GaN island diameters, after LT-GaN annealing, on the u-GaN resistivity was not confirmed.

Słowa kluczowe

EN

GaN; nucleation; recrystallization; metalorganic chemical vapor deposition; nitrides; LED; MSM; MESFET devices

• Wydawca: Oficyna Wydawnicza Politechniki Wrocławskiej
• Czasopismo: Optica Applicata
• Rocznik: 2019
• Tom: Vol. 49, nr 1
• Strony: 167--176
• Opis fizyczny: Bibliogr. 12 poz., rys.

Twórcy

autor

Wośko Mateusz

• Faculty of Microsystem Electronics and Photonic, Wrocław University of Science and Technology, Janiszewskiego 11/17, 50-372 Wrocław, Poland

Bibliografia

• [1] AMANO H., AKASAKI I., HIRAMATSU K., KOIDE N., SAWAKI N., Effects of the buffer layer in metalorganic vapour phase epitaxy of GaN on sapphire substrate, Thin Solid Films 163, 1988, pp. 415–420, DOI: 10.1016/0040-6090(88)90458-0.
• [2] WU X.H., FINI P., TARSA E.J., HEYING B., KELLER S., MISHRA U.K., DENBAARS S.P., SPECK J.S., Dislocation generation in GaN heteroepitaxy, Journal of Crystal Growth 189–190, 1998, pp. 231–243, DOI: 10.1016/S0022-0248(98)00240-1.
• [3] WU X.H., KAPOLNEK D., TARSA E.J., HEYING B., KELLER S., KELLER B.P., MISHRA U.K., DENBAARS S.P., SPECK J.S., Nucleation layer evolution in metal-organic chemical vapor deposition grown GaN, Applied Physics Letters 68(10), 1996, pp. 1371–1373, DOI: 10.1063/1.116083.
• [4] AKASAKI I., AMANO H., KOIDE Y., HIRAMATSU K., SAWAKI N., Effects of ain buffer layer on crystallographic structure and on electrical and optical properties of GaN and Ga1–xAlxN (0 < x ≤ 0.4) films grown on sapphire substrate by MOVPE, Journal of Crystal Growth 98(1–2), 1989, pp. 209–219, DOI: 10.1016/0022-0248(89)90200-5.
• [5] KAPOLNEK D., WU X.H., HEYING B., KELLER S., KELLER B.P., MISHRA U.K., DENBAARS S.P., SPECK J.S., Structural evolution in epitaxial metalorganic chemical vapor deposition grown GaN films on sapphire, Applied Physics Letters 67(11), 1995, p. 1541, DOI: 10.1063/1.114486.
• [6] CHEN J., ZHANG S., ZHANG B., ZHU J., FENG G., DUAN L., WANG Y., YANG H., ZHENG W., Influence of growth pressure of a GaN buffer layer on the properties of MOCVD GaN, Science in China Series E 46(6), 2003, pp. 620–626, DOI: 10.1360/03ye0038.
• [7] WICKENDEN A.E., KOLESKE D.D., HENRY R.L., TWIGG M.E., FATEMI M., Resistivity control in unintentionally doped GaN films grown by MOCVD, Journal of Crystal Growth 260(1–2), 2004, pp. 54–62, DOI: 10.1016/j.jcrysgro.2003.08.024.
• [8] HUBBARD S.M., ZHAO G., PAVLIDIS D., SUTTON W., CHO E., High-resistivity GaN buffer templates and their optimization for GaN-based HFET’s, Journal of Crystal Growth 284(3–4), 2005, pp. 297–305, DOI: 10.1016/j.jcrysgro.2005.06.022.
• [9] KOLESKE D.D., WICKENDEN A.E., HENRY R.L., TWIGG M.E., Influence of MOVPE growth conditions on carbon and silicon concentrations in GaN, Journal of Crystal Growth 242(1–2), 2002, pp. 55–69, DOI: 10.1016/S0022-0248(02)01348-9.
• [10] GRZEGORCZYK A.P., MACHT L., HAGEMAN P.R., RUDZINSKI M., LARSEN P.K., Resistivity control of unintentionally doped GaN films, Physica Status Solidi C 2(7), 2005, pp. 2113–2116, DOI: 10.1002/ pssc.200461415.
• [11] MITA S., COLLAZO R., DALMAU R., SITAR Z., Growth of higly resistive Ga-polar GaN by LP-MOVPE, Physica Status Solidi C 4(7), 2007, pp. 2260–2263, DOI: 10.1002/pssc.200674837.
• [12] PASZKIEWICZ B., WOSKO M., PASZKIEWICZ R., TLACZALA M., Nondestructive method for evaluation of electrical parameters of AlGaN/GaN HEMT heterostructures, Physica Status Solidi C 10(3), 2013, pp. 490–493, DOI: 10.1002/pssc.201200709.

Uwagi

PL

Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2019).