本論文探討在微波頻段中，高阻值矽基板(111)上的氮化鋁鎵/氮化鎵高電子遷移率電晶體其高頻高功率的特性。利用鋅摻雜以及蝕刻元件隔離平台的兩種絕緣方法、改變元件閘極金屬的厚度，以及探討在閘極至汲極端加入浮動蕭特基金屬線對於元件特性的影響。
閘極長度0.5μm，汲極至源極2.5μm的元件其最大飽和電流與最大轉導增益分別為764mA/mm與223mS/mm，其高頻特性為fT=26GHz、fMAX=61.2GHz。而鋅摻雜絕緣改善蝕刻絕緣平台的元件關閉狀態下的漏電流至nA，但是在直流以及高頻特性上沒有顯著的不同。閘極金屬厚度降低，將導致閘極電阻的上升使得高頻特性變差。加上浮動蕭特基金屬線的元件，可以降低元件關閉狀態下的漏電流約2個數量級，但是在高頻特性上則會使得fT、fMAX降低。由小訊號電路模型的萃取過程可知，其肇因為Cgs的上升的緣故。
功率特性上，經由2.4GHz load-pull量測，傳統元件在Class AB的偏壓點下可得到功率增益17.83dB，PAE=49.8%的高頻輸出。加上浮動蕭特基金屬線的元件，則僅有功率增益15.49dB，PAE=29.7%的高頻輸出。

[1] J. Millán, “Wide band-gap power semiconductor devices,” IET Circuits Devices Syst., vol. 1, no. 5, pp. 372 – 379, Oct. 2007.
[2] O. Ambacher; J. Smart; J. R. Shealy; N. G. Weimann; K. Chu; M. Murphy; W. J. Schaff; L. F. Eastman; R. Dimitrov; L. Wittmer; M. Stutzmann; W. Rieger; 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, Mar. 1999.
[3] F. Sacconi; A.D. Carlo; P. Lugli; and H. Morkoç, “Spontaneous and Piezoelectric Polarization Effects on the Output Characteristics of AlGaN/GaN Heterojunction Modulation Doped FETs,” IEEE Transactions on Electron Devices, vol. 48, no. 3, pp. 450-457, 2001.
[4] S. Kolluri; Yi Pei; S. Keller; S. P. Denbaars; U.K. Mishra, “RF Performance of N-Polar AlGaN/GaN MIS-HEMTs Grown by MOCVD on Sapphire Substrate,” IEEE Electron Device Lett., vol. 30, no. 6, pp. 584-586, Jun. 2009.
[5] M. H. Wong; Y. Pei; D. F. Brown; S. Keller; J. S. Speck; U.K. Mishra, “High performance N-face GaN microwave MIS-HEMTs with > 70% power-added efficiency,” IEEE Electron Device Lett., vol. 30, no. 8, pp. 802-804, Aug. 2009.
[6] J. W. Chung; E. L. Piner; T. Palacios, “N-face GaN/AlGaN HEMTs fabricated through layer transfer technology,” IEEE Electron Device Lett., vol. 30, no. 2, pp. 113-116, Feb. 2009.
[7] S. Keller; Y. F. Wu; G. Parish; N. Ziang; J. J. Xu; B. P. Keller; S. P. DenBaars; U. K. Mishra, “Gallium Nitride Based High Power Heterojunction Field Effect Transistors: Process Development and Present Status at UCSB,” IEEE Electron Device Lett., vol. 48, no. 3, pp. 552-559, Mar. 2001.
[8] L. K. Li; B. Turk; W. I. Wang; S. Syed; D. Simonian, “High electron mobility AlGaN/GaN heterostructures grown on sapphire substrates by molecular-beam epitaxy,” Appl. Phys. Lett., vol. 76, no. 6, pp. 742-744, Feb. 2000.
[9] R. Gaska; A. Osinsky; J. W. Yang; M. S. Shur, “Self-heating in high-power AlGaN-GaN HFETs,” IEEE Electron Device Lett., vol. 19, no. 3, pp. 89-91, Mar. 1998.
[10] Y. F. Wu; M. Moore; A. Saxler; T. Wisleder; P. Parikh, “40-W/mm Double Field-plated GaN HEMTs,” Device Research Conference, pp. 151-152, 2006.
[11] R. Chu; L. Shen; N. Fichtenbaum; D. Brown; Z. Chen; S. Keller; S. P. DenBaars; U. K. Mishra, “V-Gate GaN HEMTs for X-Band Power Applications,” IEEE Electron Device Lett., vol. 29, no. 9, pp. 974-976, Sep. 2008.
[12] J. W. Chung; W. E. Hoke; E. M. Chumbes; T. Palacios, “AlGaN/GaN HEMT With 300-GHz fmax,” IEEE Electron Device Lett., vol. 31, no. 3, pp. 195-197, Mar. 2010.
[13]S. Joblota; F. Semond; Y. Cordier; P. Lorenzini; and J. Massies, “High-electron-mobility AlGaN/GaN heterostructures grown on Si (001) by molecular-beam epitaxy,” Appl. Phys. Lett. 87, no.13, p. 133 505, Sep. 2005.
[14] S. Hoshi; M. Itoh; T. Marui; H. Okita; Y. Morino; I. Tamai; F. Toda; S. Seki; T. Egawa, “12.88W/mm GaN High Electron Mobility Transistor on Silicon Substrate for High Voltage Operation,” Applied Physics Express, vol. 2, no. 6, pp. 061001, 2009.
[15] S. Tirelli; D. Marti; H. Sun; A. R. Alt; H. Benedickter; E. L. Piner; C. R. Bolognesi, “107-GHz (Al,Ga)N/GaN HEMTs on Silicon With Improved Maximum Oscillation Frequencies,” IEEE Electron Device Lett., vol. 31, no. 4, pp. 296-298, Apr. 2010.
[16] S. M. Sze, Physics of Semiconductor Devices. New York: Wiley, 1981, pp. 342–343.
[17] T. R. Prunty; J. A. Smart; E. N. Chumbes; B. K. Ridley; L. F. Eastman; J. R. Shealy, “Passivation of AIGaN/GaN Heterostructures with Silicon Nitride For Insulated Gate Transistors,” in Proc. IEEE/Cornell High-Performance Devices Conf., pp. 208–214, 2000.
[18] P. Kordoš; P. K´udela; D. Gregušov´a; D. Donoval1, “The effect of passivation on the performance of AlGaN/GaN heterostructure field-effect transistors,” Semicond. Sci. Technol., vol. 21, no. 12, 2006.
[19] N. Pala; X. Hu; J. Deng; J. Yang; R. Gaska; Z. Yang; A. Koudymov; M.S. Shur; G. Simin,“Drain-to-Gate Field Engineering for Improved Frequency Response of GaN-based HEMTs,” Solid-State Electronics, vol. 52, no. 8, pp. 1217-1220, Aug. 2008.
[20] V. Kumar; G. Chen; S. Guo; I. Adesida, “Field-Plated 0.25-μm Gate-Length AlGaN/GaN HEMTs With Varying Field-Plate Length,” IEEE Trans. Electron Devices, vol. 53, no. 6, pp. 1477-1480, Jun. 2006.
[21] G. Dambrine; A. Cappy; F. Heliodore; E. Playez, “A New Method for Determining the FET Small-Signal Equivalent Circuit,” IEEE Trans. Microwme Theory Tech., vol. 36, no. 7, pp. 1151-1159, Jul. 1988.
[22] F. Diamand; M. Laviron, “Elements of Microwave MESFET under Zero Current Conditions,” 12 th European Microwave Conference Proceedings, pp. 451-6, Sep. 1982.
[23] E. Chigaeva; W. Walthes; D. Wiegner; M. Grozing; F. Schaich; N. Wieser; M. Berroth; O. Breitschadel; L. Kley; B. Kuhn; F. Scholz; H. Schweizer; O. Ambacher; J. Hilsenbeck, “Determination of Small-Signal Parameters of GaN-based HEMTs,” Proceedings 2000 IEEE, Cornell Conference of High performance Devices.
[24] M. Berroth; R. Bosch, “Broad-band determination of the FET smallsignal equivalent circuit,” IEEE Trans. Microwave Theory Tech., vol. 38, no. 7, pp. 891–895, Jul. 1990.