砷化銦/銻化鋁高電子遷移率電晶體非常適合應用於低功率、高速之電子元件。也因其材料系統的能帶為第二型能帶對齊方式且為低能隙造成二個嚴重的缺點，一個為在高閘極偏壓時會產生電洞穿遂效應。一個為在高電場下會發生衝擊離化所產生的電洞無法侷限於導通層中造成漏電流增加。因此置入一高介電係數薄膜在閘極之下以期降低漏電流。
我們先對氧化鋁薄膜進行物性及電性分析，物性包括有厚度鑑定、組成成份、表面粗糙度及熱穩定性。電性包括有不同基板的電容-電壓量測、漏電流與崩潰電場量測。此外我們將氧化鋁薄膜置入傳統的砷化銦/銻化鋁高電子遷移率電晶體磊晶層上製作出砷化銦/銻化鋁 金屬-氧化物-高電子遷移率電晶體。在閘極長度為2μm的元件上汲極電流可達286 mA/mm，轉導可達495mS/mm在汲極偏壓為0.4V時，次臨界斜率可達416(mV/dec)，介面捕獲電荷密度可達1~2 1011eV-1cm-2，漏電流比傳統HEMT降低2~3個數量級且有良好的高頻特性ft，fMAX分別為10.1 GHz，19.1GHz在汲極偏壓為0.5 V時，閘極偏壓為-2.6 V時。

InAs/AlSb high electron mobility transistor has great promise in high speed and low power applications. However, two drawbacks observed in the devices are closely associated with type II band line-up and small bandgap InAs channel. One is band-to-band hole tunneling; another is serious carrier impact ionization. Generated holes cannot be confined in the channel and result in serious kink and gate currents. In the thesis, we deposit a high-k Al2O3 dielectric under the gate to alleviate the gate leakage.
We first analyzed electrical and physical properties of the Al2O3 thin film. The physical properties include thin film thickness, composition, surface roughness and thermal stability. The electrical properties include C-V measurement, I-V measurement and J-E measurement. Different substrates are chosen for these characterizations. Based on the developed high-k mdielectric, we fabricated InAs/AlSb MOS-HEMTs using the conventional InAs/AlSb HEMT epitaxy materials. In a device with 2.0?m gate length, maximum drain current is 286mA/mm and peak transconductance is 495mS/mm at drain voltage of 0.4V. The subthreshold slope is 416mV/dec. The interface trap density is 1~2 1011 eV-1cm-2. The gate leakage current was suppressed at least 2~3 order compared with conventional HEMT. An fT of 10.1 GHz and an fmax of 19.9 GHz are obtained respectively at VDS = 0.5 V and VGS = - 2.6V.

[1] L. D. Nguyen, A. S. Brown, M. A. Thompson, and L. M. Jelloian, “50 nm self-aligned-gate pseudomorphic AlInAs/GaInAs high electron mobility transistors,” IEEE Trans. Electron Dev., vol. 39, pp. 2007-2014, 1992.
[2] C. Nguyen, B. Brar, C. R. Bolognesi, J. J. Pekarik, H. Kroemer, and J. H. English, “Growth of InAs/AlSb quantum wells having both high mobilities and high electron concentrations,” J. Electron. Mat., vol. 22, pp. 255-258, 1993.
[3] J. Bergman, G. Nagy, G. Sullivan, A. Ikhlassi, B. Brar, C. Kadow, H.-K. Lin, A. Gossard, and M. Rodwell, “Low-voltage, higher-performance InAs/AlSb HEMTs with power gain above 100GHz at 100Mv drain bias,” in Proc. 62st Device Research Conference, pp. 243-244, 2004.
[4] H. K. Lin, “The Design, Growth, and Characterization of Antimonide-Based Composite-Channel Heterostructure Field-Effect Transistors,” Ph.D. dissertation, UC Santa Barbara, 2004.
[5] B. Brar, “Impact ionization in InAs-AlSb heterostructure field-effect-transistors,” Ph.D. dissertation, UC Santa Barbara, 1995.
[6] C. R. Bolognesi, “The Physics, Design, Growth, and Characterization of Millimeter-Wave InAs/AlSb-Based Heterostructure Field-Effect Transistors,” Ph.D. dissertation, UC Santa Barbara, 1993.
[7] R. H. Dennard, F. H. Gaensslen, V. L. Rideout, E. Bassous, and A. R. LeBlanc, Design of ion-implanted MOSFET’s with very small physical dimensions, IEEE J. Solid-State Circuit, vol 9, p.265, 1974.
[8] Clen D. Wilk Robert M. Wallace, “Exploring the limits of gate dielectric scaling”, Semicond. Int. June, 153, 2001.
[9] S.M.Sze, Kwok K. Ng, “Physics of Semiconductor Devices”, pp.297-298,Third Edition.
[10] 鄭崇銘, “氧化鉿-氧化鈮閘極介電薄膜之特性研究,” 碩士論文, 國立成功大學, 2007.
[11] 陳逸書, “以稀土氧化物Y2O3為金氧化場效電晶體閘極氧化層之研究,” 碩士論文, 私立中原大學, 2002.
[12] D. A. Buchanan, E. P. Gusev, E. Cartier, H. Okorn-Schmidt, K. Rim, M. A. Gribelyuk, A. Mocuta, A. Ajmera, M. Copel, S. Guha, N. Bojarczuk, A. Callegari, C. D. Emic, P. Kozlowski, K. Chan, R. J. Fleming, P. C. Jamison, J. Brown, and R. Arndt, in Proceedings of the IEEE International Electron Devices Meeting, p. 223, 2000.
[13] G. D. Wilk, R. M. Wallace, J. M. Anthony,” High-k gate dielectrics: Current status and materials properties considerations”, J. Appl. Phys. 89, pp.5243-5275, 2001
[14] S. Datta, T. Ashley, J. Brask, L. Buckle, M. Doczy, M. Emeny, D. Hayes, K. Hilton, R. Jefferies, T. Martin, T. J. Phillips, D. Wallis, P. Wilding* and R. Chau, “85nm Gate Length Enhancement and Depletion mode InSb Quantum Well Transistors for Ultra High Speed and Very Low Power Digital Logic Applications”, IEEE, 2005
[15] P. D. Ye, B. Yang, K. K. Ng, and J. Bude, G. D. Wilk, S. Halder and J. C. M. Hwang, “GaN metal-oxide-semiconductor high-electron-mobility-transistor with atomic layer deposited Al2O3 as gate dielectric”, Appl. Phys. Lett., 86, 2005.
[16] Hyoung-Sub Kim, at etl, “High mobility HfO2-based In0.53Ga0.47As n-channel
metal-oxide-semiconductor field effect transistors using a germanium interfacial passivation layer” ,Appl. Phys. Lett., 93, 2008.
[17] C. Nguyen, B. Brar, and H. Kroemer,” Surface-layer modulation of electron concentrations in InAs–AlSb quantum wells,” J. Vac. Sci. Technol. B., vol11, pp. 1706-1709, 1993
[18] Brian R. Bennett, M. J. Yang, B. V. Shanabrook, J. B. Boos, and D. Park, “ Modulation doping of InAs/AlSb quantum wells using remote InAs donor layers”, Appl. Phys. Lett, vol. 72, pp.1193-1195, 1996.
[19] M. Kudo and T. Mishima, “MBE growth of Si-doped InA1AsSb layers
lattice-matched with InAs”, J. Cryst Growth., 175, pp. 844-848, 1997
[20] 戴國良, “離子輔助反應射頻磁控濺鍍紫外光薄膜之研究”, 碩士論文, 國立中央大學, (2001).
[21] J. D. Werking, C. R. Bolognesi, L.-D. Chang, C. Nguyen, E. L. Hu, and
H. Kroemer, “High-transconductance InAs/AlSb heterojunction field-effect transistors with δ-doped AlSb upper barriers” IEEE Electron Device Lett., vol13, pp.164-166 , 1992.
[22] Agilent 4284A Precision LCR Meter, Manual Change, 2004
[23] M. Plasslack et al., “Low Dit Thermodynamically Stable Ga2O3-GaAs Interfaces: Fabrication, Characterization, and Modeling”, IEEE Transactions on electron device, vol44, pp.214-225, 1997.
[24] 陳毅驊, “以Y2O3為矽閘極介電層之金氧化特性之研究”, 碩士論文, 私立中原大學, 2003.
[25] A. Aßmuth, T. Stimpel-Lindner, O. Senftleben, A. Bayerstadler, T. Sulima, H. Baumga¨rtner, I. Eisele, “ The role of atomic hydrogen in pre-epitaxial silicon substrate cleaning“ Applied Surface Science., vol253, pp.8389–8393, (2007)
[26] G. Mavrou , S. F. Galata, A. Sotiropoulos, P. Tsipas, Y. Panayiotatos, A. Dimoulas, E. K. Evangelou, J.W. Seo, Ch. Dieker, “Germanium metal-insulator-semiconductor capacitors with rare earth La2O3 gate dielectric” Microelectronic Engineering., vol 84, pp. 2324–2327, 2007
[27] 鄭紹章, “氮化鋁鎵/氮化鎵高電子移導率電晶體製作於矽基板與藍寶石基板之特性比較與應用電路”, 碩士論文, 中央大學, 2007.
[28] N Chaturvedi, U Zeimer, J Würfl and G Tränkle,” Mechanism of ohmic contact
formation in AlGaN/GaN high electron mobility transistors”, Semicond. Science
Technology., vol21, pp. 175-179, 2006.
[29] Malin Borg, Eric Lefebvre, Mikael Malmkvist1, Ludovic Desplanque, Xavier Wallart, Yannick Roelens, Gilles Dambrine, Alain Cappy, Sylvain Bollaert, and Jan Grahn, “DC AND RF PERFORMANCE OF 0.2-0.4 ptm GATE LENGTH InAs/AlSb HEMTs”, 19th IPRM, pp.14 - 18, 2007.
[30] X. Hu, A. Koudymov, G. Simin, J. Yang, and M. Asif Khan, A. Tarakji, M. S. Shur, and R. Gaska, “Si3N4 AlGaN/GaN–metal–insulator–semiconductor heterostructure field–effect transistors”, Appl. Phys. Lett., vol79, pp2382-2384, 2001.