本論文致力於液相氧化法在磷化銦鎵/砷化銦鎵假晶高電子移動率電晶體作為閘極介電層之應用。相較於其他的氧化法而言，液相氧化法是一種在低溫下(30-70°C)簡易及經濟的化學方法，不需要額外電壓或能量輔助。而使用穿透式電子顯微鏡證實在氧化三十分鐘後有一6奈米厚度之氧化層。
應用本氧化法於閘極長度及寬度為0.7微米×100微米之高電子移動率電晶體元件上，傳統高電子移動率電晶體最大轉導138 mS/mm，逆向崩潰電壓為-6.6 V；金氧半高電子移動率電晶體最大轉導可提升至151 mS/mm，逆向崩潰電壓可達-13.8 V。在高頻特性方面，傳統高電子移動率電晶體與金氧半高電子移動率電晶體之截止頻率分別為11.3 GHz及15.79 GHz，最大震盪頻率分別可達18.46 GHz及22.3 GHz。在功率量測操作頻率為2.4 GHz時，傳統高電子移動率電晶體可獲得小訊號功率增益為10.41 dB，飽和輸出功率為13.8 dBm (119.94 mW/mm)及最大功率附加效率為29.2%；而金氧半高電子移動率電晶體小訊號功率增益可提升為11.91 dB，飽和輸出功率為14.62 dBm (144.87 mW/mm)及最大功率附加效率為37.8%。
在本研究中，利用液相氧化法於磷化銦鎵高電子移動率電晶體元件上作為閘極介電層，得到直流及高頻特性的提升，證明其具有高功率和無線通訊的應用潛力。

Native oxide as gate insulators on InGaP/InGaAs pseudomorphic high electron mobility transistors (PHEMT) were fabricated and characterized in this thesis through a liquid phase oxidation (LPO) method. Compared with others, the LPO is a simple, economic, and effective technique used to form a native oxide layer on GaAs material, at near-room temperature (30-70°C) without any other extra energy.
Additionally, transmission electron microscope analysis indicated that an oxide layer with a thickness of 6 nm actually existed on the InGaP surface 30 minutes after the LPO process. As such, we demonstrated the implementation of LPO on InGaP as effective gate insulators that improved InGaP/InGaAs pHEMTs performance. In this work, the gate length and width of the device was 0.7μm×100μm, while the peak extrinsic transconductance and the breakdown voltage for the MOS-pHEMTs (conventional pHEMTs) were 151 (138) mS/mm and -13.8 (-6.6) V, respectively.
Furthermore, the cut-off frequencies and maximum oscillation frequencies of the MOS-pHEMTs (conventional pHEMTs) were 15.8 (11.35) GHz and 22.3 (18.46) GHz, respectively. In addition, the proposed MOS-pHEMTs improved the saturated output power from 13.8dBm (119.94mW/mm) to 14.62 dBm (144.87mW/mm). The maximum small-signal increased from 10.41dB to 11.91 dB, and the maximum power-added-efficiency rose from 29.2% to 37.8%.
According to the DC and RF results, the LPO method could be considered a promising procedure for applying InGaP/InGaAs pHEMTs to high power and wireless communication applications.

[1] F. Ali and A. Gupta, HEMTS and HBTS: Devices, Fabrication and Circuits, Boston London: Artech House, 1991.
[2] F. Schwierz and J J. Liou, Modern Microwave Transistors: Theory, Design, and Performance, USA, New Jersey, John Wiley & Sons, Inc, 2002.
[3] R. Dingle, H. L. Störmer, A. C. Gossard and W. Wiegmann, “Electron mobility in modulation-doped semiconductor hetero-junction superlattices,” Appl. Phys. Lett.,

vol 33, pp. 665-667, 1978.
[4] H. L. Störmer, R. Dingle, A. C. Gossard, W. Wiegmann and M. D. Sturge, “Two dimensional electron gas at a semiconductor–semiconductor interface ,” Solid-State
Comm., vol. 29, pp. 705-709, 1979.
[5] S. Subramanian, “Model for the temperature dependence of the threshold voltage of modulation-doped field-effect transistors,” IEEE Trans. Electron Dev., vol. 32,

pp. 865-870, 1985.
[6] J. W. Matthews and A. E. Blakeslee, “Defects in epitaxial multilayers: I. Misfit dislocations,” J. Crystal Growth, vol. 27, pp. 118-125, 1974.
[7] Ketterson, M. Moloney, W. T. Masselink, J. Klem, R.Fischer, W. Kopp and H. Morkoc,“High transconductance AlGaAs/InGaAs/GaAs pseudomorphic modulation-doped
field-effect Transistors,” IEEE Electron Dev. Lett., vol. 6, pp. 628-630, 1985.
[8] C.Y. Chang and F. Kai, GaAs high-speed devices: physics, technology, and circuit applications, USA, New Jersey, John Wiley & Sons, Inc, 2003.
[9] M. A. Rao, E. J. Caine, H. Kroemer, S. I. Long and D. I. Babic, “Determination of valence and conduction-band discontinuites at the (Ga,In) P/GaAs heterojunction

by C-V profiling,” J. Appl. Phys., vol. 61, pp. 643-649, 1987.
[10] R. Menozzi, P. Cova, C. Canali and F. Fantini, “Breakdown walkout in pseudormorphic HEMT’S,” IEEE Trans. Electron Dev., vol. 43, pp. 543-546, 1996.
[11] S. Fujita, T. Noda, A. Wagai, C. Noxaki and Y. Ashizawa, “Novel HEMT structure using a strained InGaP Schottky layer,” in 5th Proc. of Indium Phosphide and

Relsted Materials, Paris, France, April 19-22, 1993, pp. 497-500.
[12] H. K. Huang, C. S. Wang, Y. H. Wang, C. L. Wu and C. S. Chang, “Temperature effects of low noise InGaP/InGaAs/GaAs PHEMTS,” Solide-State Electron., vol. 47, pp.
1989-1994, 2003.
[13] Y. S. Lin, S. S. Lu and Y. J. Wang, “High-performance GaInP/GaAs airbridge gate MISFET’S grown by gas-source MBE,” IEEE Trans. Electron Dev., vol. 44, pp. 921

-929, 1997.
[14] W. C. Liu, W. L. Chang, W. S. Lour, H. J. Pan, W. C. Wang, J. Y. Chen, K. H. Yu, and S. C. Feng, “High-performance InGaP/InxGa1-xAs HEMT with an inverted delta-

doped V-shaped channel structure, ” IEEE Electron Dev. Lett., vol. 20, p. 548, 1999.
[15] K. W. Lee, Y. J. Lin, N. Y. Yang, Y. C. Lee, P. W. Sze, Y. H. Wang and M. P. Houng,“InGaP/InGaAs/GaAs metal-oxide semiconductor pseudomorphic high electron
mobility transistor with a liquid phase oxidized InGaP gate ,” in proceedings of 7th IEEE International Conference on Solid-State and Integrated Circuits Technology

(ICSICT), Beijing, China, Oct. 18-21, 2004, pp. 2301-2304.
[16] H. Kinoshita, Y. Sano, T. Ishida, S. Nishi, M. Akiyama and K. Kaminishi, “A new insulated-gate inverted-structure modulation-doped AlGaAs/GaAs/N-AlGaAs
field-effect transistor,” Jpn. J. Appl. Phys.,vol. 43, no. 11, pp. L836–L838, Nov. 1984.
[17] S. Fujita, M. Hirano, and T. Mizutani, “Small-signal characteristics of n+-Ge gate AlGaAs/GaAs MISFETs,” IEEE Electron Dev. Lett., vol. 9, no. 10, pp. 518–520,

Oct.1988.
[18] H. H. Wang, J. Y. Wu, Y. H. Wang and M. P. Houng, “Effect of PH values on the kinetics of liquid phase chemical enhanced oxidation of GaAs,” J. Electronchem.

Soc., vol. 146, pp. 2328-2332, 1999.
[19] H. H. Wang, Y. H. Wang and M. P. Houng, “Near room temperature selective oxidation on GaAs using photoresist as a mask,” Jpn. J. Appl. Phys., vol. 37, pp. L988

-990, 1998.
[20] J. Y. Wu, H. H. Wang, Y. H. Wang and M. P. Houng, “A GaAs MOSFET with a liquid phase oxidized gate,” IEEE Electron Dev. Lett., vol. 20, pp. 18-20, 1999.
[21] J. Y. Wu, H. H. Wang, Y. H. Wang and M. P. Houng, “GaAs MOSFET’s fabrication with a liquid phase oxidized gate,” IEEE Trans. Electron Dev., vol. 48, pp. 634-

637, 2001.
[22] K. W. Lee, P. W. Sze, Y. H. Wang and M. P. Houng, “Liquid phase chemical enhanced oxidation on AlGaAs and its application,” Jpn. J. Appl. Phys., vol. 43, pp.

4087-4091, 2001.
[23] K. W. Lee, P. W. Sze, Y. H. Wang and M. P. Houng, “AlGaAs/InGaAs metal-oxide-semiconductor pseudomorphic high-electron–mobility transistor with a
liquid phase oxidized AlGaAs as gate dielectric,” Solid-State Electron., vol. 49, pp. 213-217, 2005.
[24] K. W. Lee, N. Y. Yang, M. P. Houng and Y. H Wang, “Improved breakdown voltage and impact ionization in InAlAs/InGaAs metamorphic high-electron-mobility

transistor with a liquid phase oxidized InGaAs gate,” Appl. Phys. Lett., vol. 87, pp. 263501-1-263501-3, 2005.
[25] K. W. Lee, K. L. Lee, H. C. Lin, C. H. Tu, C. C. Hu, and Y. H. Wang,“Near-room-temperature selective oxidation on InAlAs and application to
In0.52Al0.48As/In0.53Ga0.47As metamorphic HEMTs,” J. Electrochem. Soc., vol. 154, no. 11, pp. H957-H961, 2007.
[26] K. W. Lee, P. W. Sze, Y. J. Lin, N. Y. Yang, M. P. Houng and Y. H. Wang,“InGaP/InGaAs metal-oxide semiconductor pseudomorphic high-electron-mobility
transistor with a liquid-phase-oxidized InGaP as gate dielectric ,” IEEE Electron Dev. Lett., vol. 26, pp. 864-866, 2005.
[27] H. C. Lin, K. W. Lee, C. H. Tu, P. W. Sze and Y. H. Wang, “InGaP/InGaAs MOS-pHEMT with a liquid phase oxidized InGaP gate insulator,” in IEEE Conf. on
Electron Devices and Solid-State Circuits (EDSCC), Tainan, Taiwan, Dec. 20-22, 2007, pp.181-184.
[28] M. Passlack, M. Hong, E. F. Schubert, G. J. Zydzik, J. P. Mannaerts, W. S. Hobson and T. Harris, “Advancing metal -oxide-semiconductor, theory: steady state

nonequilibrium conditions,” J. Appl. Phys., Vol. 8 I , no. 11, pp. 7647-7661, 1997.
[29] F. Ren, M. Hong, W. S. Hobson, J. M. Kuo, J. R. Lothian, J. P Mannaem, J. Kwo, S. N. G. Cho and A. Y. Cho, “Demonstration of enhancement-mode p- and n-channel

GaAs MOSFETs with Ga2O3(Gd2O3) as gate oxide,” Solid-State Electron., Vol. 41, no.11, pp. 1751-1753, 1997.
[30] M. P. Houng, Y. H. Wang, C. J. Huang, S. P. Huang and J. H. Horng, “Quality optimization of liquid phase deposition SiO2 films on gallium arsenide,” Solid-State
Electron., Vol. 44, pp. 1917-1923, 2000.
[31] Y. G. Xie, S. Kasai, H. Takahashi, C. Jiang, and H. Hasegawa, “A novel InGaAs/InAlAs insulated gate pseudomorphic HEMT with a silicon interface control
layer showing high, DC and RF performance,” IEEE Electron Dev. Lett.. Vol. 22, pp 312-314, July 2001.
[32] N. C. Paul, M. Takebe, M. Tametou, H. Seto, Y. Fukino, K. Iiyama and S. Takamiya, “N-channel, p-channel, depletion, enhancement GaAs metal-Insulator-

semiconductor field effect transistors with gate films formed by oxi-nitridation of GaAs surfaces,” in IEEE Conf. on Indium Phosphide and Related Materials, May,

2005, pp.246-249.
[33] S. K. Ghandhi, VLSI Fabrication Principles: Silicon and Gallium Arsenide, New York: John Wiley & Sons, Inc., 1994.
[34] D. J. Coleman, D. W. Shaw and R. D. Dobott, “On the mechanism of GaAs anodization,” J. Electrochem. Soc., vol. 124, pp. 239-241, 1977.
[35] E. Kohn, “A Correlation Between Etch Characteristics of GaAs Etch Solutions Containing and Surface Film Characteristics,” J. Electrochem. Soc.: SOLID-STATE
SCIENCE AND TECHNOLOGY, Vol. 127, No. 2, 1980
[36] J. R. Meyer-Arendt, Introduction to classical and modern optics, Englewood Cliffs, N. J.: Prentice-Hall Inc., 1971.
[37] T. Sugano, “Oxidation of GaAs1-xPx surface by oxygen plasma and properties of oxide film,” J. Electrochem. Soc., vol. 121, pp. 113-118, 1974
[38] M. Sadaka, D.l Hill, F. Clayton, H. Henry, C. Rampley, J .Abrokwah, and R. Uscola,“Development of Motorola’s InGaP HBT Process,” GaAsMANTECH, Inc., 2002.
[39] K. W. Lee, P. W. Sze, K. L. Lee, M. P. Houng and Y. H. Wang, “InGaP PHEMT with a liquid phase oxidized InGaP as gate dielectric,” in IEEE Conf. on Electron

Devices and Solid-State Circuits (EDSSC), Hong Kong, China, Dec. 19-21, pp.609-612, 2005.
[40] K. Inoue, J. C. Harmand and T. Matsumo, “High-quality InxGa1-xAs/InAlAs modulation-doped heterostrctures grown lattice-mismatched on GaAs substrates,” J.
Crystal Growth, vol. 111, pp. 313-317, 1992.
[41] K. W. Lee, K. L. Lee, X. Z. Lin, C. H. Tu and Y. H. Wang, “Improvement of impact ionization effect and subthreshold current in InAlAs/InGaAs
metal–oxide–semiconductor metamorphic HEMT with a liquid-phase oxidized InAlAs as gate insulator,” IEEE Electron Dev., vol. 54, pp.418-424, 2007.
[42] I. Thayne, “Advanced Ⅲ-Ⅳ HEMTs,” The advanced semiconductor magazine, vol.16, pp. 48-51, 2003.
[43] C. L. Lau, M. Feng, T. R. Lepkowski, G. W. Wang, Y. Chang and C. Ito,“Half-micrometer gate-length ion-implanted GaAs MESFET with 0.8-dB noise figure
at 16 GHz,” IEEE Electron Dev. Lett., vol. 10, pp. 409-411, 1989.
[44] M. J. Bailey, “Intermodulation distortion in pseudomorphic HEMTs and an extension of the classical theory,” IEEE Trans. Microwave Theory Tech., vol. 48, pp.

104-110, Jan. 2000.
[45] C. K. Chu, “3.3 V self-biased 2.4~2.5GHz power amplifier MMIC,” Dep. E. E., NCKU, pp.53-55, 2002.