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Design, Microfabrication, and Characterization of Polar III-Nitride HFETs

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Design, Microfabrication, and Characterization of Polar III-Nitride HFETs

Loghmany, Alireza (2016) Design, Microfabrication, and Characterization of Polar III-Nitride HFETs. PhD thesis, Concordia University.

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Abstract

ABSTRACT
Design, Microfabrication, and Characterization of Polar III-Nitride HFETs
Alireza Loghmany, Ph.D.
Concordia University, 2016
With excellent performance in high-frequency power amplifiers, AlGaN/GaN heterojunction field-effect transistors (HFETs) as next generation power amplifiers have drawn a great deal of attention in the last decade. These HFETs, however, are still quite limited by their inherently depletion-mode (D-mode: negative pinch-off voltage) nature, relatively poor gate-leakage, and questionable long-terms reliability. In addition, since AlGaN/GaN HFETs operate at extremely high-power densities, performance of these devices has so far remained quite limited by self-heating effects.
While a number of techniques have already been developed for realization of enhancement-mode (E-mode: positive pinch-off voltage) AlGaN/GaN HFETs, these techniques in addition to having a number of difficulties in achieving enhancement-/depletion-mode pairs, fall short of satisfying requirements such as low leakage-current, drain-current stability, and pinch-off voltage stability at the high operating temperatures and at elevated electric-fields. Among these techniques, fluoride-based plasma treatment is the most widely accepted. As an alternative to this mainstream technique, polarization-engineering of AlGaN/GaN HFETs through exploring the impacts of the mesa geometry is studied as a possible avenue for selective transformation of the D-mode nature of AlGaN/GaN HFETs to an E-mode character. Whereas limited experimental studies on the pinch-off voltage of HFETs realized on different isolation-feature geometries have indicated the presence of a certain correlation between the two, such observations lack the required depth to accurately identify the true culprit. This technique is expected to be ultimately capable of producing enhancement-/depletion-mode pairs without adding any extra steps to the microfabrication process.
In light of this requirement, microfabrication of AlGaN/GaN HFETs using a number of alternative isolation-feature geometries is explored in this study. In addition to developing an in-house microfabrication process, transistors designed according to these novel isolation-feature geometries have been fabricated through the services offered by Canadian Microelectronics Corporation (CMC). Investigation of the variation of pinch-off voltage among the devices fabricated through this latter means has conclusively indicated that the pinch-off voltage shift, rather than exclusively being caused by the surrounding-field effect, is also correlated to the perimeter-to-area ratio of the isolation-features.
In addition, through characterization and thermal modeling of these groups of devices, in this study a new approach is unveiled for reducing self-heating in AlGaN/GaN HFETs. According to finite element analysis (FEA) and electrical measurement of average channel temperature, an improved heat-dissipation was observed in HFETs enjoying a more distributed nature of the two-dimensional electron gas (2DEG) channel. This is observed to be the case especially for isolation features which offered the center of the channel a smaller distance to the side walls. Observations also indicate a more distinct gain in thermal management with reduction of the gate-length and also the surface area of the isolation pattern. Results suggest that self-heating in AlGaN/GaN HFETs can be substantially nullified by reducing the island-width below a certain threshold value, while maintaining the total width of the transistor constant.
In addition to exploring these alternatives on AlGaN/GaN HFET structures, in-house microfabrication of AlN/GaN MISFETs is also studied. The results of DC characterization of these novel transistors are also presented.

Divisions:Concordia University > Gina Cody School of Engineering and Computer Science > Electrical and Computer Engineering
Item Type:Thesis (PhD)
Authors:Loghmany, Alireza
Institution:Concordia University
Degree Name:Ph. D.
Program:Electrical and Computer Engineering
Date:29 June 2016
Thesis Supervisor(s):Valizadeh, Pouya
ID Code:981388
Deposited By: ALIREZA LOGHMANY
Deposited On:09 Nov 2016 15:21
Last Modified:18 Jan 2018 17:53

References:

Bibliography
[1] U. Mishra, L. Shen, T. Kazior, and Y. Wu, “GaN-based RF power devices and amplifiers,” Proc. of the IEEE, vol. 96, no. 2, pp. 287-305, Feb. 2008.
[2] J. Wu, W. Walukiewicz, K. Yu, J. Ager III, E. Haller, H. Lu, W. Schaff, Y. Saito, and
Y. Nanishi, “Unusual properties of the fundamental bandgap of InN,” App. Phys. Lett., vol. 80, no. 21, pp. 3967-3969, May 2002.
[3] M. Levinshtein, S. Rumyantsev, and M. Shur, Properties of advance semiconductor materials, J. Wiley and sons, 2001.
[4] www.gansystems.com, accessed Nov. 2013.
[5] U. Mishra, P. Parikh, and Y. Wu, “AlGaN/GaN HEMTs-An overview of device operations and applications,” Proc. of the IEEE, vol. 90, no. 6, pp. 1022-1031, June 2002.
[6] O. Ambacher, J. Smart, J. Shealy, N. Weimann, K. Chu, M. Murphy, W. Schaff, L. Eastman, R. Dimitrov, L. Wittmer, M. Stutzmann, W. Rieger, and J. Hilsenbeck, “Two-dimensional electron gases induced by spontaneous and piezoelectric polarization charges in N- and Ga-face AlGaN/GaN heterostructures,” J. Appl. Phys., vol. 85, no. 6, pp. 3222-3233, Mar. 1999.
[7] M. Khan, J. Kuznia, D. Olson, W. Schaff, J. Burm, and M. Shur, “Microwave performance of a 0.25 μm gate AlGaN/GaN heterostructure field effect transistor,” App. Phys. Lett., vol. 65, no. 9, pp. 1121-1123, Aug. 1994.
[8] C. Chen, S. Keller, E. Haberer, L. Zhang, S. DenBaars, E. Hu, and U. Mishra, “Cl2 reactive ion etching for gate recessing of AlGaN/GaN field-effect transistors,” J. Vac. Sci. Technol. B, vol. 17, no. 6, pp. 2755-2758, Nov. 1999.
[9] M. Neuburger, T. Zimmermann, E. Kohn, A. Dadgar, F. Schulze, A. Krischill, M. Gunther, H. Witte, J. Blasing, A. Krost, I. Daumiller, and M. Kunze, “Unstrained AlInN/GaN FET,” Int. J. High Speed Electron. Syst., vol. 14, no. 3, pp. 785-790, Sept. 2004.
[10] T. Palacois, A. Chakraborty, S. Heikman, S. Keller, S. DenBaars, and U. Mishra, “AlGaN/GaN high electron mobility transistors with InGaN back-barriers,” IEEE Electron Device Lett., vol. 27, no. 1, pp. 13-15, Jan. 2006.
[11] M. Micovic, P. Hashimoto, M. Hu, I. Milosavljevic, J. Duvall, P. Willadsen, W.Wong, A. Conway, A. Kurdoghlian, P. Deelman, J. Moon, A. Schmitz, and M. Delaney, “GaN double heterojunction field effect transistor for microwave and millimeter wave power applications,” IEDM Tech. Dig., pp. 807-810, Dec. 2004.
[12] F. Recht, L. McCarthy, S. Rajan, A. Chakraborty, C. Poblenz, A. Corrion, J. Speck, and U. Mishra, “Non-alloyed Ohmic contacts in AlGaN/GaN HEMTs by ion implantation with reduced activation annealing temperature,” IEEE Electron Device Lett., vol. 27, no. 4, pp. 205-207, Apr. 2006.
[13] M. Werquin, N. Vellas, Y. Guhel, D. Cucatteau, B. Boudart, J. Pesant, Z. Bougrioua, M. Germain, J. De Jaeger, and C. Gaquiere, “First results of AlGaN/GaN HEMTs on sapphire substrate using an argon-ion implant isolation technology,” Microw. Opt. Technol. Lett., vol. 46, no. 4, pp. 311-315, Aug. 2005.
[14] Y. Cai, Y. Zhou, K. Lau, and K. Chen, “High performance enhancement-mode AlGaN/GaN HEMTs using fluoride-based plasma treatment,” IEEE Electron Device Lett., vol. 26, no. 7, pp. 435-437, July 2005.
[15] K. Ohi and T. Hashizume, “Drain current stability and controllability of threshold voltage and subthreshold current in a multi-mesa-channel AlGaN/GaN high electron mobility transistor,” Jpn. J. Appl. Phys., vol. 48, no. 8, pp. 081002-1-081002-5, Aug. 2009.
[16] M. Alsharef, R. Granzner, and F. Schwierz, “Theoretical investigation of trigate AlGaN/GaN HEMTs,” IEEE Trans. Electron Devices, vol. 60, no. 10, pp. 3355-3341, Oct. 2013.
[17] P. Valizadeh and B. AlOtaibi, “Fin-and island-isolated AlGaN/GaN HFETs,” IEEE Trans. Electron Devices, vol. 58, no. 2, pp. 1404-1407, May 2011.
[18] I. Smorchkova, L. Chen, T. Mates, L. Shen, S. Heikman, B. Moran, S. Keller, S. DenBaars, J. Speck, and U. Mishra, “AlN/GaN and (Al, Ga) N/AlN/GaN two-dimensional electron gas structures grown by plasma-assisted molecular-beam epitaxy,” J. Appl. Phys., vol. 90, no. 10, pp. 5196-1-5196-6, Aug. 2001.
[19] S. Taking, D. MacFarlane, and E. Wasige, “AlN/GaN MOS-HEMTs with thermally grown Al2O3 passivation,” IEEE Trans. Electron Devices, vol. 58, no. 5, pp. 1418-1424, May 2011.
[20] T. Zimmermann, D. Deen, Y. Cao, J. Simon, P. Fay, D. Jena, and H. Xing, “AlN/GaN insulated-gate HEMTs with 2.3 A/mm output current and 480 mS/mm transconductance,” IEEE Electron Device Lett., vol. 29, no. 7, pp. 661-664, July 2008.
[21] D. Deen, T. Zimmermann, Y. Cao, D. Jena, and H. Xing, “2.3 nm barrier AlN/GaN HEMTs with insulated gates,” Phys. Status Solidi (C), vol. 5, no. 6, pp. 2047-2049, May 2008.
[22] J. Chung, O. Saadat, J. Tirado, X. Gao, S. Guo, and T. Palacios, “Gate-recessed InAlN/GaN HEMTs on SiC substrate with Al2O3 passivation,” IEEE Electron Device Lett., vol. 30, no. 9, pp. 904-906, Sept. 2009.
[23] Y. Yue, Z. Hu, J. Guo, B. Sensale-Rodriguez, G. Li, R. Wang, F. Faria, T. Fang, B. Song, X. Gao, S. Guo, T. Kosel, G. Snider, P. Fay, D. Jena, and H. Xing, “InAlN/AlN/GaN HEMTs with regrown Ohmic contacts and fT of 370 GHz,” IEEE Electron Device Lett., vol. 33, no. 7, pp. 988-990, July 2012.
[24] R. Wang, P. Saunier, Y. Tang, T. Fang, X. Gao, S. Guo, G. Snider, P. Fay, D. Jena, and H. Xing, “Enhancement-mode InAlN/AlN/GaN HEMTs with 10−12 A/mm leakage current and 1012 on/off current ratio,” IEEE Electron Device Lett., vol. 32, no. 3, pp. 309-311, Mar. 2011.
[25] R. Wang, G. Li, G. Karbasian, J. Guo, B. Song, Y. Yue, Z. Hu, O. Laboutin, Y. Cao, W. Johnson, G. Snider, P. Fay, D. Jena, and H. Xing, “Quaternary barrier InAlGaN HEMTs with fT /fmax of 230/300 GHz,” IEEE Electron Device Lett., vol. 34, no. 3, pp. 378-380, Mar. 2013.
[26] R. Wang, G. Li, J. Verma, B. Sensale-Rodriguez, T. Fang, J. Guo, Z. Hu, O. Laboutin, Y. Cao, W. Johnson, G. Snider, P. Fay, D. Jena, and H. Xing, “220-GHz quaternary barrier InAlGaN/AlN/GaN HEMTs,” IEEE Electron Device Lett., vol. 32, no. 9, pp. 1215-1217, Sept. 2011.
[27] S. Imanaga and H. Kawai, “Simulation of the piezoelectric effect on the device characteristics of AlGaN/GaN insulated-gate heterostructure field effect transistors,” Jpn. J. Appl. Phys., vol. 37, no. 11, pp. 5906-5913, Nov. 1998.
[28] S. Seo, “High frequency MIS-based III-nitride transistor and integrated bio-sensor technology,” Ph.D. dissertation, Univ. Michigan, Ann Arbor, MI, 2009.
[29] H. Morkoç, Handbook of Nitride Semiconductors and Devices, vol. 1: Materials Properties, Physics and Growth, Weinheim: Wiley, 2009.
[30] S. Strite and H. Morkoç, “GaN, AlN, and InN: A review,” J. Vac. Sci. Technol. B, vol. 10, pp. 1237-1266, July 1992.
[31] F. Fichter, “Uber Aluminiumnitrid,” Z. Anorg. Chem., vol. 54, p. 322, 1907.
[32] R. Juza and H. Hahn, “Über die kristallstrukturen von Cu3N, GaN und InN metallamide und metallnitride,” Z. Anorg. Chem., vol. 239, no. 3, pp. 282-287, Oct. 1938.
[33] H. Maruska and J. Tietjen, “The preparation and properties of vapor‐deposited single‐crystal‐line GaN,” Appl. Phys. Lett., vol. 15, no. 10, pp. 327-329, Nov. 1969.
[34] H. Manasevit and F. Erdmann, “The use of metalorganics in the preparation of semiconductor materials, IV. The Nitrides of Aluminum and Gallium,” J. Elecchem. Soc., vol. 18, no. 11, pp. 1864-1867, Nov. 1971.
[35] I. Akasaki and I. Hayashi, “The use MBE in the preparation of semiconductor materials,” Ind. Sci. Tech., vol. 17, pp. 48-52, 1976.
[36] K. Ploog, O Brandt, H. Yang, B. Yang, and A. Trampert “Nucleation and growth of GaN layers on GaAs, Si, and SiC substrates,” J. Vac. Sci. Technol. B, vol. 16, no. 4, pp. 2229-2236, July 1998.
[37] S. Yoshida, S. Misawa, and S. Gonda “Improvements on the electrical and luminescent properties of reactive molecular beam epitaxially grown GaN films by using AlN‐coated sapphire substrates,” Appl. Phys. Lett., vol. 42, no. 5, pp. 427-429, Mar. 1983.
[38] H. Amano, N. Sawaki, I. Akasaki, and Y. Toyoda “Metalorganic vapor phase epitaxial growth of a high quality GaN film using an AlN buffer layer,” Appl. Phys. Lett., vol. 48, no. 5, pp. 353-355, Feb. 1986.
[39] H. Amano, I. Akasaki, K. Hiramatsu, N. Koide, N. Sawaki, “Effects of the buffer layer in metalorganic vapour phase epitaxy of GaN on sapphire substrate,” Thin Solid Films, vol. 163, pp. 415-420, Dec. 1988.
[40] L. Liu and J. Edgar, “Substrates for gallium nitride epitaxy,” Mater. Sci. Eng.: R-Rep., vol. 37, no. 3, pp. 61-127, Apr. 2002.
[41] T. Hino, S. Tomiya, T. Miyajima, K. Yanashima, S. Hashimoto, and M. Ikeda, “Characterization of threading dislocations in GaN epitaxial layers,” App. Phy. Lett., vol. 76, no. 23, pp. 3421-3423, June 2000.
[42] S. Ren and J. Dow “Lattice‐matching SiC substrates with GaN,” Appl. Phys. Lett., vol. 69, no. 2, pp. 251-253, July 1996.
[43] C. Wood and D. Jena, Polarization Effects in Semiconductors: From Ab Initio Theory to Device Applications, Springer, 2008.
[44] S. Kukushkin, A. Osipov, V. Bessolov, B. Medvedev, V. Nevolin, and K. Tcarik “Substrates for epitaxy of Gallium nitride: new materials and techniques,” Rev. Adv. Mater. Sci., vol. 17, pp. 1-32, Mar. 2008.
[45] S. Adachi, Properties of Group-IV, III-V and II-VI Semiconductors, John Wiley and Sons, Chichester, England, 2005.
[46] F. Bernardini, V. Fiorentini, and D. Vanderbilt, “Spontaneous polarization and piezoelectric constants of III-V nitrides,” Phys. Rev. B, vol. 56, no. 16, pp. Rl-0-024-Rl-0-027, Oct. 1997.
[47] E. Yu and E. Manasreh, “Spontaneous and piezoelectric polarization in nitride heterostructures,” III-V Nitride Semiconductors: Applications and Devices (Optoelectronic Properties of Semiconductors and Superlattices), pp. 161-193, Taylor & Francis, 2003.
[48] U. Mishra and J. Singh, Semiconductor device physics and design, Springer, 2008.
[49] Y. Wei, Z. Renping, D. Yandong, H. Weihua, and Y. Fuhua, “Analysis of the Ohmic contacts of Ti/Al/Ni/Au to AlGaN/GaN HEMTs by the multi-step annealing process,” J. Semicon., vol. 33, no. 6, pp. 064005-1-064005-6, June, 2012.
[50] Y. Cao and D. Jena, “High-mobility window for two-dimensional electron gases at ultrathin AlN/GaN heterojunctions,” Appl. Phys. Lett., vol. 90, no. 18, p. 182112-1-182112-3, Apr. 2007.
[51] R. Trew, D. Green, and J. Shealy, “AlGaN/GaN HFET reliability,” IEEE Microwave, vol. 10, no. 4, pp. 116-127, June 2009.
[52] M. Shur, R Gaska, and A Bykhovski, “GaN-based electronic devices,” Solid-State Electron., vol. 43, no. 8, pp. 1451-1458, Aug. 1999.
[53] R. Vetury, N. Zhang, S. Keller, and U. Mishra, “The impact of surface states on the DC and RF characteristics of AlGaN/GaN HFETs,” IEEE Trans. Electron Devices, vol. 48, no. 3, pp. 560-566, Mar. 2001.
[54] P. Valizadeh and D. Pavlidis, “Low frequency noise-based monitoring of the effects of RF and DC stress on AlGaN/GaN MODFETs,” proc. of GaAs IC Symp., pp. 78-81, Nov. 2003.
[55] X. Hu, A. Koudymov, G. Simin, J. Yang, M. Khan, A. Tarakji, M. Shur, and R. Gaska, “Si3N4/AlGaN/GaN-metal-insulator-semiconductor heterostructure field effect transistors,” App. Phys. Lett., vol. 79, no. 17, pp. 2832-2834, Oct. 2001.
[56] H. Leier, A. Vescan, R. Dietrich, A. Wieszt, and H. Sledzik, “RF characterisation and transient behaviour of AlGaN/GaN power HFETs,” IEICE Trans. Electron., vol. E84-C, no. 10, pp. 1442-1447, Oct. 2001.
[57] G. Simin, A. Koudymov, A. Tarakji, X. Hu, J. Yang, M. Asif Khan, M. Shur, and R. Gaska, “Induced strain mechanism of current collapse in AlGaN/GaN heterostructure field-effect transistors,” Appl. Phys. Lett., vol. 79, no. 16, pp. 2651-2653, Oct. 2001.
[58] S. Arulkumaran, T. Egawa, H. Ishikawa, and T. Jimbo, “Comparative study of drain-current collapse in AlGaN/GaN high-electron mobility transistors on sapphire and semi-insulating SiC,” Appl. Phys. Lett., vol. 81, no. 16, pp. 3073-3075, Oct. 2002.
[59] H. Kim, A. Vertiatchikh, R. Thompson, V. Tilak, T. Prunty, J. Shealy, and L. Eastman, “Hot electron induced degradation of undoped AlGaN/GaN HFETs,” Microelectron. Rel., vol. 43, no. 6, pp. 823-827, June 2003.
[60] W. Lu, V. Kumar, R. Schwindt, E. Piner, and I. Adesida, “A comparative study of surface passivation on AlGaN/GaN HEMTs,” Solid-State Electron., vol. 46, no. 9, pp. 1441-1444, Sept. 2002.
[61] B. Green, K. Chu, E. Chumbes, J. Smart, J. Shealy, and L. Eastman, “The effect of surface passivation on the microwave characteristics of undoped AlGaN/GaN HEMTs,” IEEE Electron Device Lett., vol. 21, no. 6, pp. 268-270, June 2000.
[62] W. Tan, P. Houston, P. Parbrook, G. Hill, and R. Airey, “Comparison of different surface passivation dielectrics in AlGaN/GaN heterostructure field-effect transistors,” J. Phys. D: Appl. Phys., vol. 35, no. 7, pp. 595-598, Apr. 2002.
[63] T. Kikkawa, M. Nagahara, N. Okamobo, Y. Tatero, Y. Yamaguchi, and N. Hara, “Surface-charged controlled AlGaN/GaN power HFET without current collapse and gm dispersion,” IEDM Tech Dig., pp. 585-588. Dec. 2001.
[64] W. Saito, Y. Kakiuchi, T. Nitta, Y. Saito, T. Noda, H. Fujimoto, A. Yoshioka, T. Ohno, and M. Yamaguchi, “Field-plate structure dependence of current collapse phenomena in high-voltage GaN-HEMTs,” IEEE Electron Device Lett., vol. 31, no. 7, pp. 659-661, July 2010.
[65] A. Edwards , J. Mittereder, S. Binari, D Scott Katzer, D. Storm, and J. Roussos, “Improved reliability of AlGaN-GaN HEMTs using an NH3 plasma treatment prior to SiN passivation,” IEEE Electron Deice Lett., vol. 26, no. 4, pp. 225-227, Apr. 2005.
[66] L. Shen, R. Coffie, D. Buttari, S. Heikman, A. Chakraborty, A. Chini, S. Keller, S. DenBaars, U. Mishra, “High-power polarization-engineered GaN/AlGaN/GaN HEMTs without surface passivation,” IEEE Electron Device Lett., vol. 25, no. 1, pp. 7-9, Jan. 2004.
[67] N. Tsurumi, H. Ueno, T. Murata, H. Ishida, Y. Uemoto, T. Ueda, K. Inoue, and T. Tanaka, “AlN passivation over AlGaN/GaN HFETs for surface heat spreading,” IEEE Trans. Electron Devices, vol. 57, no. 5, pp. 980-985, May 2010.
[68] O. Mitrofanov, M. Manfra, “Mechanisms of gate lag in GaN/AlGaN/GaN high electron mobility transistors,” Superlattices and Microstruct., vol. 34, no. 1-2, pp. 33-35. July 2003.
[69] P. Klein, S. Binari, K. Ikossi-Anastasiou, A. Wickenden, D. Koleske, R. Henry, and D. Katzer, “Investigation of traps producing current collapse in AlGaN/GaN high electron mobility transistors,” Electron. Lett., vol. 37, no. 10, pp. 661-662, May 2001.
[70] X. Zhou, Z. Feng, L. Wang, Y. Wang, Y. Lv, S. Dun, S. Cai, “Impact of bulk traps in GaN buffer on the gate-lag transient characteristics of AlGaN/GaN HEMTs,” Solid-State Electron., vol. 100, pp. 15-19, Oct. 2014.
[71] N. Braga, R. Mickevicius, R. Gaska, M. Shur, M. Khan, and G. Simin, “Simulation of gate lag and current collapse in gallium nitride field-effect transistors,” Appl. Phys. Lett., vol. 85, no. 20, pp. 4780-4782, Nov. 2004.
[72] H. Kim, J. Lee, and W. Lu, “Post-annealing effects on trapping behaviors in AlGaN/GaN HEMTs,” phys. status solidi (a), vol. 202, no. 5, pp. 841-845, Apr. 2005.
[73] T. Hashizume, J. Kotani, A. Basile, and M. Kaneko, “Surface control process of AlGaN for suppression of gate leakage currents in AlGaN/GaN heterostructure field effect transistors,” Jpn. J. Appl. Phys., vol. 45, no. 4, pp. L111-L113, Jan. 2006.
[74] E. Miller, X. Dang, and E. Yu, “Gate leakage current mechanisms in AlGaN/GaN heterostructure field-effect transistors,” J. Appl. Phys., vol. 88, no. 10, pp. 5951-5958, Nov. 2000.
[75] J. Zhang, J. Yuan, Y. Ma, and A. Oates, “Surface roughness effect on gate leakage and C-V characteristics of deep submicron MOSFETs,” Integrated Reliability Workshop, California, USA, pp. 133-136, Jan. 2001.
[76] S. Arulkumaran, T. Egawa, H. Ishikawa, T. Jimbo, and Y. Sano, “Surface passivation effects on AlGaN/GaN high-electron-mobility transistors with SiO2 , Si3N4 , and silicon oxynitride,” Appl. Phys. Lett., vol. 84, no. 4, pp. 613-615, Jan. 2004.
[77] G. Meneghesso, G. Verzellesi, F. Danesin, F. Rampazzo, F. Zanon, A. Tazzoli, M. Meneghini, and E. Zanoni, “Reliability of GaN high-electron-mobility transistors: state of the art and perspectives,” IEEE Trans. Dev. Mat. Rel., vol. 8, no. 2, pp. 332-343, June 2008.
[78] H. Kim, J. Lee, D. Liu, and W. Lu, “Gate current leakage and breakdown mechanism in unpassivated AlGaN/GaN high electron mobility transistors by post-gate annealing,” Appl. Phys. Lett., vol. 86, no. 14, pp. 143505-1-143505-3, Mar. 2005.
[79] Y. Oshimura, K.Takeda, T. Sugiyama, M. Iwaya, S. Kamiyama, H. Amano, I. Akasaki, A. Bandoh, and T. Udagawa, “AlGaN/GaN HFETs on Fe-doped GaN substrates,” Phys. Status Solidi (c), vol. 7, no. 7-8, pp. 1974-1976, July 2010.
[80] M. Belousov, B. Volf, J. Ramer, E. Armour, and A. Gurary, “In situ metrology advances in MOCVD growth of GaN-based materials,” J. Crys. Growth, vol. 272, no. 1-4, pp. 94-99, Dec. 2004.
[81] J. Neugebauer, C. Van de Walle, “Atomic geometry and electronic structure of native defects in GaN,” Phys. rev. B, vol. 79, no. 11, pp. 8067-8070, Sept. 1994.
[82] T. Mukai, K. Takekawa, and S. Nakamura, “InGaN-based blue light-emitting diodes grown on epitaxially laterally overgrown GaN substrates,” Jpn. J. Appl. Phys., vol. 37, no. 7, pp L839-L841, July 1998.
[83] M. Piazza, C. Dua, M. Oualli, E. Morvan, D. Carisetti, and F. Wyczisk, “Degradation of TiAlNiAu as Ohmic contact metal for GaN HEMTs,” Microelectron. Rel., vol. 48, no. 9-11, pp. 122-1225, Sept. 2009.
[84] Y. Chou, D. Leung, I Smorchkova, M. Wojtowicz, R. Grundbacher, L. Callejo, Q Kan, R. Lai, H. Liu, D. Eng, and A. Oki, “Degradation of AlGaN/GaN HEMTs under elevated temperature life testing,” Microelectron. Rel., vol. 44, no. 7, pp 1033-1038, July 2004.
[85] N. Miura, T. Nanjo, M. Suita, T. Oishi, Y. Abe, T. Ozeki, H. Ishikawa, T. Egawa, and T. Jimbo, “Thermal annealing effects on Ni/Au based Schottky contacts on n-GaN and AlGaN/GaN with insertion of high work function metal,” Solid-State Electron., vol. 48, no. 5, pp. 689-695, May 2004.
[86] S. Singhal, J. Roberts, P. Rajagopal, T. Li, A. Hanson, R. Therrien, J. Johnson, J. Kizilyalli, and K. Linthicum, “GaN-on-Si failure mechanisms and reliability improvements,” Proc. of 44th Annual IEEE International Rel. Phys. Sym., San Jose, CA, USA, pp. 26-30 Mar. 2006.
[87] Y. Okamoto ,Y. Ando, K. Hataya, T. Nakayama, H. Miyamoto, T. Inoue, M. Senda, K. Hirata, M. Kosaki, N. Shibata, and M. Kuzuhara, “Improved power performance for a recessed-gate AlGaN–GaN heterojunction FET with a field-modulating plate,” IEEE Trans. on Microw. Theory Tech., vol. 52, no. 11, pp. 2536-2540, Nov. 2004.
[88] J. del Alamo and J. Joh, “GaN HEMT reliability,” Microelectron. Rel., vol. 49, no. 9-11, pp. 1200-1206, Sep. 2009.
[89] R. Gaska, A. Osinsky, J. Yang, and M. Shur, “Self-heating in high-power AlGaN-GaN HFETs,” IEEE Electron Devices Lett., vol. 19, no. 3, pp. 89-91, Mar. 1998.
[90] A. Chini, V. Di Lecce, M. Esposto, G. Meneghesso, and E. Zanoni, “RF degradation of GaN HEMTs and its correlation with DC stress and I-DLTS measurements,” Proc. European Microw. Integr. Circuits Conf., Rome, Italy, pp. 28-29, Sept. 2009.
[91] J. Joh, J del Alamo, K. Langworthy, S. Xie, and T. Zheleva, “Role of stress voltage on structural degradation of GaN high-electron-mobility transistors,” Microelectron. Rel., vol. 51, no. 2, pp. 201-206, Feb. 2011.
[92] B. Benbakhti, A. Soltani, K. Kalna, M. Rousseau, and J. De Jaeger, “Effects of self-heating on performance degradation in AlGaN/GaN based devices,” IEEE Trans. Electron Devices, vol. 56, no. 10, pp. 2178-2185, Oct. 2009.
[93] R. Gaska, A. Osinsky, J. Yang, and M. Shur, “Self-heating in highpower AlGaN-GaN HFETs,” IEEE Electron Device Lett., vol. 19, no. 3, pp. 89-91, Mar. 1998.
[94] M. Kuball, J. Hayes, M. Uren, T. Martin, J. Birbeck, R. Balmer, and B. Hughes, “Measurement of temperature in active high-power AlGaN/GaN HFETs using Raman spectroscopy,” IEEE Electron Device Lett., vol. 23, no. 1, pp. 7-9, Jan. 2002.
[95] I. Ahmad, V. Kasisomayajula, M. Holtz, J. Berg, S. Kurtz, C. Tigges, A. Allerman, and A. Baca, “Self-heating study of an AlGaN/GaN-based heterostructure field-effect transistor using ultraviolet micro-Raman scattering,” Appl. Phys. Lett., vol. 86, no. 17, pp. 173503-1-173503-5, Apr. 2005.
[96] K. Chabak, J. Gillespie, V. Miller, A. Crespo, J. Roussos, M. Trejo, D. Walker, G. Via, G. Jessen, J. Wasserbauer, F. Faili, D. Babic, D. Francis, and F. Ejeckam, “Full-wafer characterization of AlGaN/GaN HEMTs on free-standing CVD diamond substrates,” IEEE Electron Device Lett., vol. 31, no. 2, pp. 99-101, Feb. 2010.
[97] J. Pomeroy, M. Bernardoni, D. Dumka, D. Fanning, and M. Kuball, “Low thermal resistance GaN-on-diamond transistors characterized by three-dimensional Raman thermography mapping,” App. Phys. Lett., vol. 104, no. 8, p. 083513-1-083513-5, Feb. 2014.
[98] M. Seelman-Eggebert, P. Meisen, F. Schaudela, P. Koidla, A. Vescanb, and H. Leier, “Heat spreading diamond films for GaN-based high power transistor devices,” Diamond Relat. Mater., vol. 10, no. 3-7, pp. 744-749, Mar./July 2001.
[99] A. Sarua, H. Ji, K. Hilton, D. Wallis, M. Uren, T. Martin, and M. Kuball, “Thermal boundary resistance between GaN and substrate in AlGaN/GaN electronic devices,” IEEE Trans. Electron Devices, vol. 54, no. 12, pp. 3152-3158, Dec. 2007.
[100] Electronic Archive of New Semiconductor Materials, Characteristics and Properties: Gallium Nitride [Online]. Available: http://www.ioffe.rssi.ru/SVA/NSM/Semicond/GaN/index.html, accessed Mar. 15, 2014.
[101] Electronic Archive of New Semiconductor Materials, Characteristics and Properties: Silicon Carbide [Online]. Available: http://www.ioffe.rssi.ru/SVA/NSM/Semicond/SiC/index.html, accessed Mar. 15, 2014.
[102] M. Moradi, “Analytical modeling of drain-current characteristics of AlGaN/GaN HFETs with incorporation of the impacts of virtual-gate and transferred-electron effect,” MASc. thesis, Dept. Electr. Comput. Eng., Univ. Concordia, Montreal, QC, Canada, June 2010.
[103] J. Joh, J. del Alamo, U. Chowdhury, T. Chou, H. Tserng, and J. Jimenez, “Measurement of channel temperature in GaN high electron mobility transistors,” IEEE Trans. Electron Devices, vol. 56, no. 12, pp. 2895-2901, Dec. 2009.
[104] S. Martin-Horcajo, A. Wang, and M. Romero, “Simple and accurate method to estimate channel temperature and thermal resistance in AlGaN/GaN HEMTs,” IEEE Trans. Electron Devices, vol. 60, no. 12, pp. 4105-4111, Dec. 2013.
[105] J. DiLorenzo and D. Khandelwal, GaAs FET Principles and Technology. Norwood, Artech House, 1982, pp. 308-347.
[106] F. Manouchehri, P. Valizadeh, and M. Z. Kabir, “Temperature-dependent investigation of low frequency noise characteristics of mesa-, fin-, and island-isolated AlGaN/GaN HFETs,” Solid-State Electron., vol. 89, pp. 1-6, Nov. 2013.
[107] V. Fiorentini, F. Bernardini, and O. Ambacher, “Evidence for nonlinear macroscopic polarization in III-V nitride alloy heterostructures,” Appl. Phys. Lett., vol. 80, no.7, pp.1204-1206, Feb. 2002.
[108] W. Lanford, T. Tanaka, Y. Otoki, and I. Adesida, “Recessed-gate enhancement-mode GaN HEMT with high threshold voltage,” Electron. Lett., vol. 41, no. 7, pp. 449-450, Mar. 2005.
[109] K. Ohi, J. Asubar, K. Nishiguchi, and T. Hashizume, “Current stability in multi-mesa-channel AlGaN/GaN HEMTs,” IEEE Trans. Electron Devices, vol. 60, no. 10, pp. 2997-3004, Oct. 2013.
[110] S. Liu, Y. Cai, G. Gu, J. Wang, C. Zeng, W. Shi, Z. Feng, H. Qin, Z. Cheng, K. Chen, and B. Zhang, “Enhancement-mode operation of nano-channel array (NCA) AlGaN/GaN HEMTs,” IEEE Electron Devices Lett., vol. 33, no. 3, pp. 354-356, Mar. 2012.
[111] B. Lu, “AlGaN/GaN-based power semiconductor switches,” Dept. of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, Ph.D. dissertation, June 2013.
[112] K. Im, C. Won, Y. Jo, J. Lee, M. Bawedin, S. Cristoloveanu, and J. Lee, “High-performance GaN-based nanochannel FinFETs with/without AlGaN/GaN heterostructure,” IEEE Trans. Electron Devices, vol. 60, no. 10, pp. 3012-3018, Oct. 2013.
[113] S. Takashima, Z. Li, and T. Chow, “Sidewall dominated characteristics on Fin-Gate AlGaN/GaN MOS-channel-HEMTs,” IEEE Trans. Electron Devices, vol. 60, no. 10, pp. 3025-3031, Oct. 2013.
[114] H. Hahn, B. Reuters, A. Wille, N. Ketteniss, F. Benkhelifa, O. Ambacher, H. Kalisch, and A. Vescan, “First polarization-engineered compressively strained AlInGaN barrier enhancement-mode MISHFET,” Semicond. Sci. Technol., vol. 27, no. 5, pp. 0550041-0550046, Mar. 2012.
[115] I. Hwang, J. Kim, H. Choi, H. Choi, J. Lee, K. Kim, J. Park, J. Lee, J. Ha, J. Oh, J. Shin, and U. Chung, “p-GaN gate HEMTs with tungsten gate metal for high threshold voltage and low gate current,” IEEE Electron Devices Lett., vol. 34, no. 2, pp. 202-204, Feb. 2013.
[116] T. Lalinský, G. Vanko, A. Vincze, Š. Haščík, J. Osvald, D. Donoval, M. Tomáška, and I. Kostič, “Effect of fluorine interface redistribution on performance of AlGaN/GaN HEMTs,” Microelectron. Eng., vol. 88, no. 2, pp. 166-169, Feb. 2011.
[117] S. Senturia, Microsystem Design. New York: Springer-Verlag; 2000.
[118] http://www.nextnano.com/nextnano3, accessed Nov. 2013.
[119] G. Meneghesso, F. Rampazzo, P. Kordos, G. Verzellesi, and E. Zanoni, “Current collapse and high-electric-field reliability of unpassivated GaN/AlGaN/GaN HEMTs,” IEEE Trans. Electron Devices, vol. 53, no. 12, pp. 2932-2941, Dec. 2006.
[120] G. Meneghesso, G. Verzellesi, R. Pierobon, F. Rampazzo, A. Chini, U. Mishra, C. Canali, and E. Zanoni, “Surface-related drain current dispersion effects in AlGaN-GaN HEMTs,” IEEE Trans. on Electron Devices, vol. 51, no. 10, pp. 1554-1561, Oct. 2004.
[121] O. Mitrofanov and M. Manfra, “Mechanisms of gate lag in GaN/AlGaN/GaN high electron mobility transistors,” Superlattices Microstruct., vol. 34, no. 1-2, pp. 33-53, July/Aug. 2003.
[122] Z. Fang, B. Claflin, D. Look, D. Green, and R. Vetury, “Deep traps in AlGaN/GaN heterostructures studied by deep level transient spectroscopy: Effect of carbon concentration in GaN buffer layers,” J. Appl. Phys., vol. 108, no. 6, pp. 063706-1- 063706-6, Sept. 2010.
[123] A. Polyakov and I. Lee, “Deep traps in GaN-based structures as affecting the performance of GaN devices,” Mater. Sci. Eng., vol. 94, pp. 1-56, Aug. 2015.
[124] R. Cuerdo, Y. Pei, Z. Chen, S. Keller, S. DenBaars, F. Calle, and U. Mishra, “The kink effect at cryogenic temperatures in deep submicron AlGaN/GaN HEMTs,” IEEE Electron Device Lett., vol. 30, no. 3, pp. 209-212, Mar. 2009.
[125] K. Choi, H. Jang, and J. Lee, “Observation of inductively coupled-plasma-induced damage on n-type GaN using deep-level transient spectroscopy,” App. Phys. Lett., vol. 82, no. 8, pp. 1233-1235, Feb. 2003.
[126] Z. Fand, D. Look, X. Wang, J. Han, F. Khan, and I. Adesida, “Plasma-etching-enhanced deep centers in n-GaN grown by metalorganic chemical-vapor deposition,” App. Phys. Lett., vol. 82 , no. 10, pp. 1562-1564, Mar. 2003.
[127] H. Cho, F. Khan, I. Adesida, Z. Fang, and D. Look, “Deep level characteristics in n-GaN with inductively coupled plasma damage,” J. Phys. D: Appl. Phys., vol. 41, no. 15, pp. 15531-15534, July 2008.
[128] L. Fang, S. Bo, L. Li-Wu, L. Xin-Yu, W. Ke, X. Fu-Jun, W. Yan, M. Nan, and H. Jun, “Identification and elimination of inductively coupled plasma-induced defects in AlxGa1-xN/GaN heterostructures,” Chin. Phys. B, vol. 20, no. 7, pp. 077303-1-077303-6, Mar. 2011.
[129] P. Klein, S. Binari, K. Ikossi, A. Wickenden, D. Koleske, and R. Henry, “Current collapse and the role of carbon in AlGaN/GaN high electron mobility transistors grown by metalorganic vapor-phase epitaxy,” App. Phys. Lett., vol. 79, no. 21, pp. 3527-3529, Nov. 2001.
[130] P. Klein and S. Binari, “Photoionization spectroscopy of deep defects responsible for current collapse in nitride-based field effect transistors,” J. Phys.: Condens. Matter., vol. 15, no. 44, pp. R1641-R1667, Oct. 2003.
[131] Z. Chen, Y. Pei, S. Newman, R. Chu, D. Brown, R. Chung, S. Keller, S. Denbaars, S. Nakamura, and U. Mishra, “Growth of AlGaN/GaN heterojunction field effect transistors on semi-insulating GaN using an AlGaN interlayer,” App. Phys. Lett., vol. 94, no. 11, pp. 112108-1-112108-3, Mar. 2009.
[132] P. Jogai, “Influence of surface states on the two-dimensional electron gas in AlGaN/GaN heterojunction field-effect transistors,” J. Appl. Phys., vol. 93, no. 3, pp. 1631-1635, Feb. 2003.
[133] T. Hashizume, S. Ootomo, S. Oyama, M. Konishi, and H. Hasegawa, “Chemistry and electrical properties of surfaces of GaN and GaN/AlGaN heterostructures,” J. Vac. Sci. Technol. B, vol. 19, no. 4, pp. 1675-1681, July 2001.
[134] Q. Liu and S. Lau, “A review of the metal-GaN contact technology,” Solid-State Electron., vol. 42, no. 5, pp. 677-691, May 1998.
[135] S. Binari, H. Dietrich, G. Kelner, L. Rowland, K. Doverspike, and D. Wickenden, “H, He, and N implant isolation of n-type GaN,” J. Appl. Phys., vol. 78, no. 5, pp. 30080-3011, Sept. 1995.
[136] Y. Lee, H. Kim, G. Yeom, J. Lee, M. Yoo, and T. Kim, “Etch characteristics of GaN using inductively coupled Cl2/Ar and Cl2/BCl3 plasmas,” J. Vac. Sci. and Technol. A, vol. 16, no. 3, pp. 1478-1482, Sept. 1998.
[137] R. Shul, C. Willison, M. Bridges, J. Han, J. Lee, S. Pearton, C. Abernathy, J. MacKenzie, S. Donovan, L. Zhang, and L. Lester, “Selective inductively coupled plasma etching of group-III nitrides in Cl2- and BCl3-based plasmas,” J. Vac. Sci. Technol. A, vol. 16, no. 3, pp.1621-1626, May 1998.
[138] D. Basak, M. Verdú, M. Montojo, M. Sánchez-García, F. Sánchez, E. Muñoz, and E. Calleja, “Reactive ion etching of GaN layers using SF6,” Semicond. Sci. Technol., vol. 12, no. 12, pp. 1654-1657, Sept. 1997.
[139] D. Basak, T. Nakanishi, and S. Sakai, “Reactive ion etching of GaN using BCl3, BCl3/Ar and BCl3/ N2 gas plasmas,” Solid-State Electron., vol. 44, no. 4, pp. 725-728, Apr. 2000.
[140] S. Pearton, C. Abernathy, F. Ren, J. Lothian, P. Wisk, and A. Katz, “Dry and wet etching characteristics of InN, AlN, and GaN deposited by electron cyclotron resonance metalorganic molecular beam epitaxy,” J. Vac. Sci. Technol. A, vol. 11, no. 4, July 1993.
[141] R. Dimitrov, V. Tilak, W. Yeo, B. Green, H. Kim, J. Smart, E. Chumbes, J. Shealy, W. Scha, L. Eastman, C. Miskys, O. Ambacher, and M. Stutzmann, “Influence of oxygen and methane plasma on the electrical properties of undoped AlGaN/GaN heterostructures for high power transistors,” Solid-State Electron., vol. 44, no. 8, pp. 1361-1365, Aug. 2000.
[142] A. Ping, A. Schmitz, I. Adesida, M. Asif Khan, Q. Chen, and J. Yang, “Characterization of reactive ion etching-induced damage to n-GaN surfaces using Schottky diodes,” J. Electron. Mater., vol. 26, no. 3, pp. 266-271, Mar. 1997.
[143] F. Ren, J. Lothian, S. Pearton, C. Abernahty, C. Vartuli, J. Mackenzie, R. Wilson, and R. Karlicek, “Effect of dry etching on surface properties of III-nitrides,” J. Electron. Mater., vol. 26, no. 11, pp. 1287-1291, Nov. 1997.
[144] S. Pearton, C. Abernathy, C. Vartuli, J. Lee, J. MacKenzie, R. Wilson, R. Shul, F. Ren, and J. Zavada, “Unintentional hydrogenation of GaN and related alloys during processing,” J. Vac. Sci. Technol. A, vol. 14, no. 3, pp. 831-835, May 1996.
[145] B. Molnar, C. Eddy, and K. Doverspike, “The influence of CH4/H2/Ar plasma etching on the conductivity of n-type gallium nitride,” J. Appl. Phys., vol. 78, no. 10, pp. 6132-6134, Nov. 1995.
[146] L. Wang, F. Mohammed, and I. Adesida, “Dislocation-induced nonuniform interfacial reactions of Ti/Al/Mo/Au Ohmic contacts on AlGaN/GaN heterostructure,” Appl. Phys. Lett., vol. 87, no. 14, pp. 1419151-1419153, Sept. 2005.
[147] L. Wang, F. Mohammed, and I. Adesida, “Differences in the reaction kinetics and contact formation mechanisms of annealed Ti/Al/Mo/Au Ohmic contacts on n-GaN and AlGaN/GaN epilayers,” J. Appl. Phys., vol. 101, no. 1, pp. 013702-1-013702-11, Jan. 2007.
[148] D. Qiao, L. Yu, L. Jia, P. Asbeck, S. Lau, and T. Haynes, “Transport properties of the advancing interface Ohmic contact to AlGaN/GaN heterostructures,” Appl. Phys. Lett., vol. 80, no. 6, pp. 992-994, Feb. 2002.
[149] C. Jeon, H. Jang, K. Choi, S. Bae, J. Lee, and J. Lee, “Fabrication of AlGaN/GaN heterostructure field effect transistor using room-temperature Ohmic contact,” Solid-State Electron., vol. 46, no. 5, pp. 695-698 , May 2002.
[150] S. Ruvimov, Z. Liliental-Weber, J. Washburn, D. Qiao, S. Lau, and P. Chu, “Microstructure of Ti/Al Ohmic contacts for n-AlGaN,” Appl. Phys. Lett., vol. 73, no. 18, pp. 2582-2584, Nov. 1998.
[151] D. Ingerly, Y. Chen, R. William, T. Takeuchi, and Y. Chang, “Low resistance Ohmic contacts to n-GaN and n-AlGaN using NiAl,” Appl. Phys. Lett., vol. 77, no. 3, pp. 382-384, June 2000.
[152] J. Shealy, V. Kaper, V. Tilak, T. Prunty, J. Smart, B. Green, and L. Eastman, “An AlGaN/GaN high-electron-mobility transistor with an AlN sub-buffer layer,” J. Phys.: Condens. Matter., vol. 14, no. 13, pp. 3499-3509, Mar. 2002.
[153] J. Kim, H. Jang, and J. Lee, “Mechanism for Ohmic contact formation of Ti on n-type GaN investigated using synchrotron radiation photoemission spectroscopy,” J. Appl. Phys., vol. 91, no. 11, pp. 9214-9217, June 2002.
[154] J. Neugebauer and C. Van de Walle, “Atomic geometry and electronic structure of native defects in GaN,” Phys. Rev. B, vol. 50, no. 11, pp. 8067-8070, Sept. 1994.
[155] D. Look, G. Farlow, P. Drevinsky, D. Bliss, and J. Sizelove, “On the nitrogen vacancy in GaN,” Appl. Phys. Lett., vol. 83, no. 17, pp. 3525-3527, Oct. 2003.
[156] B. Van Daele, G. Van Tendeloo, W. Ruythooren, J. Derluyn, M. R. Leys, and M. Germain, “The role of Al on Ohmic contact formation on n-type GaN and AlGaN/GaN,” Appl. Phys. Lett., vol. 87, no. 6, pp. 061905-061905, Aug. 2005.
[157] A. Soltani, A. BenMoussa, S. Touati, V. Hol, J. Jaeger, J. Laureyns, Y. Cordier, C. Marhic, M. Djouadi, and C. Dua, “Development and analysis of low resistance Ohmic contact to n-AlGaN/GaN HEMT,” Diamond Relat. Mater., vol. 16, no. 2, pp. 262-266, Feb. 2007.
[158] B. Luther, S. Mohney, T. Jackson, M. Khan, Q. Chen, and J. Yang, “Investigation of the mechanism for Ohmic contact formation in Al and Ti/Al contacts to n-type GaN,” Appl. Phys. Lett., vol. 70, no. 1, pp. 57-59, Jan. 1997.
[159] Z. Qin, Z. Chen, Y. Tong, X. Ding, X. Hu, T. Yu, and G. Zhang, “Study of Ti/Au, Ti/Al/Au, and Ti/Al/Ni/Au Ohmic contacts to n-GaN,” Appl. Phys. A: Mat, Sci. Process., vol. 78, no. 5, pp. 729-731, Mar. 2004.
[160] F. Mohammed, L.Wang, D. Selvanathan, H. Hu, and I. Adesida, “Ohmic contact formation mechanism of Ta/Al/Mo/Au and Ti/Al/Mo/Au metallizations on AlGaN/GaN HEMTs,” J. Vac. Sci. Technol. B, vol. 23, no. 6, pp. 2330-2335, Nov. 2005.
[161] B. Jacobs, M. Kramer, E. Geluk, and F. Karouta, “Optimisation of the Ti/Al/Ni/Au ohmic contact on AlGaN/GaN FET structures,” J. Cryst. Growth, vol. 241, no. 1-2, pp. 15-18, May 2002.
[162] V. Kumar, L. Zhou, D. Selvanathan, and I. Adesida, “Thermally-stable low-resistance Ti/Al/Mo/Au multilayer Ohmic contacts on n-GaN,” J. Appl. Phys., vol. 92, no. 2, pp. 1712-1714, May 2002.
[163] G. Reeves and H. Harrison, “Obtaining the specific contact resistance from transmission line model measurements,” IEEE Trans. Electron Devices, vol. 3, no. 5, pp. 111-113, May 1982.
[164] B. Jacobs, M. Kramer, E. Geluk, and F. Karouta, “Optimisation of the Ti/Al/Ni/Au Ohmic contact on AlGaN/GaN FET structures,” J. Cryst. Growth, vol. 241, no. 1-2, pp. 15-18, May 2002.
[165] S. Mohammad, Z. Fan, A. Botchkarev, W. Kim, O. Aktas, A. Salvador, and H. Morkoç, “Near-ideal platinum-GaN Schottky diodes,” Electron. Lett., vol. 32, no. 6, pp. 598-599, Mar. 1996.
[166] R. Sporken, C. Silien, F. Malengreau, K. Grigorov, R. Caudano, F. Sánchez, E. Calleja, E. Muñoz, B. Beaumont, and P. Gibart “XPS study of Au/GaN and Pt/GaN contacts,” MRS Internet J. Nitride Semicond., vol. 2, no. 23, pp. 23-32, Jan. 1997.
[167] S. Binari, H. Dietrich, G. Kelner, L. Rowland, K. Doverspike, and D. Gaskill, “Electrical characterization of Ti Schottky barriers on n-type GaN,” Electron. Lett., vol. 30, no. 11, pp. 909-911, May 1994.
[168] J. Guo, M. Feng, R. Guo, F. Pan, and C. Chang, “Study of Schottky barriers on n-type GaN grown by low-pressure metalorganic chemical vapor deposition,” Appl. Phys. Lett., vol. 67, no. 18, pp. 2657-2659, Oct. 1995.
[169] A. Schmitz, A. Ping, M. Khan, Q. Chen, J. Yang, and I. Adesida, “Schottky barrier properties of various metals on n-type GaN,” Semicond. Sci. Technol., vol. 11, no. 10, pp. 1464-1467, Oct. 1996.
[170] A. Schmitz, A. Ping, M. Khan, Q. Chen, J. Yang, I. Adesida, “Metal contacts to n-GaN,” J. Electron. Mater., vol. 27, no. 4, pp. 255-260, May 1998.
[171] H. Xing, D. Deen, Y. Cao, T. Zimmermann, P. Fay, and D. Jena, “MBE-grown ultra-shallow AlN/GaN HFET technology,” ECS Trans., vol. 11, no. 5, pp. 233-237, Oct. 2007.
[172] J. Kim, C. Won, D. Kim, Y. Jo, J. Lee, Y. Kim, S. Cristoloveanu, and J. Lee, “Growth of AlN/GaN HEMT structure using Indium-surfactant,” J. Semicon. Technol. Sci., vol. 15, no. 5, pp. 490-496, Oct. 2015.
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