氮化鎵材料有高電子飽和速度、高臨界電場及低本質載子濃度等優點，氮化鋁鎵/氮化鎵材料所形成的異質接面還會形成高濃度的二維電子氣通道(two-dimensional electron gas, 2DEG)。矽基板具有較低的成本以及方便與CMOS電路做整合使得矽基板氮化鎵(GaN-on-Silicon)符合接下來5G世代的需求。
一般的氮化鎵主被動元件都會使用金來降低歐姆接觸電阻和導線寄生電阻，但金的成本較高，尤其是被動元件需要很厚的金屬導電層，不符合經濟效益。除此之外，主動元件在高溫退火後，其金屬表面會變得粗糙，增加上層製程的難度，還可能會往下穿過阻障層並擴散到半導體基板中而導致漏電流的增加。
本實驗將採用無金製程並且搭配低溫退火的方式來取代傳統使用金的製程。在金屬方面選用鋁來取代金，鋁具有成本低和導電性佳的特性，適合拿來做商業用途。本次論文製作了毫米波電路中最常用到的元件規格，在電感方面，4.5圈的電感感值最高可到4nH，1.5圈的電感Q值最高可到10。在傳輸線方面，300μm和600μm傳輸線的return loss都很小，28GHz時大概是-36.9dB和-31.1dB，insertion loss方面大概是-0.36dB和-0.72dB。在主動元件方面，6×75μm的元件其直流特性ID,max為318mA/mm和gm,max為101mS/mm，其高頻特性fT為30.7GHz和fmax為14.5GHz，其功率特性Pout,max為18.72dBm、AP,max為13.08dB和PAEmax為24.56%。

Gallium Nitride material has the advantages of high electron saturation speed, high critical electric field and low intrinsic carrier concentration, etc. The heterojunction formed by AlGaN/GaN will also form a high-concentration two-dimensional electron gas channel. The low cost of the silicon substrate and the possibility of integration with CMOS circuits make the GaN-on-Silicon meet the needs of the 5G generation.
Generally, GaN active and passive devices use gold to reduce Ohmic contact resistance and wire parasitic resistance. However, the cost of gold is high. In particular, passive devices require a thick metal conductive layer, which is not economical. In addition, after the active device is annealed at a high temperature, its metal surface will become rough, increasing the difficulty of the upper layer process, and may also punch through the barrier layer and diffuse into the semiconductor substrate, resulting in an increase in leakage current.
This experiment will use an aluminum process with low temperature annealing to replace the traditional process using gold. Aluminum has the characteristics of low cost and good conductivity, and is suitable for commercial use. In terms of inductor, the inductance value of 4.5 turns can be as high as 4nH, and the Q value of the inductor of 1.5 turns can be as high as 10. In terms of transmission line, the return loss of 300μm and 600μm is very small, about -36.9dB and -31.1dB at 28GHz, and the insertion loss is about -0.36dB and -0.72dB. In terms of active devices, the 6×75μm device has a DC characteristic ID,max of 318mA/mm and gm,max of 101mS/mm, and its high frequency characteristic fT is 30.7GHZ and fmax is 14.5GHZ, its power characteristic Pout,max is 18.72dBm, AP,max is 13.08dB and PAEmax is 24.56%.

[1] Ambacher, "Growth and applications of group III-nitrides, " J. Physics D (Applied Physics), vol. 31, pp. 2653-2710, 1998
[2] Likun Shen, "Advanced polarization-based design of AlGaN/GaN HEMTs, " PhD thesis, University of California, Santa Barbara, 2004.
[3] B. Gelmont, K. Kim, and M. Shur, "Monte carlo simulation of electron transport in gallium nitride, " J. Appl. Phys., 74 (3), pp. 1818-1821, 1993.
[4] B. J. Baliga, "Trends in power semiconductor devices," IEEE Trans. Electron Devices, vol. 43, no. 10, pp. 1717-1731, Oct. 1996, doi: 10.1109/16.536818.
[5] 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, and J. Hilsenbeck, "Two-dimensional electron gases induced by spontaneous and piezoelectric polarization charges in N-and Ga-face AlGaN/GaN heterostructures," Journal of Applied Physics, vol.85, pp. 3222-3233, May 1999.
[6] I. Vurgaftman and J. R. Meyer, "Band parameters for nitrogen-containing semiconductors, " J. Appl. Phys., vol. 94, no. 6, pp. 3675–3696, Sep. 2003.
[7] A. Zoroddu, F. Bernardini, P. Ruggerone, and V. Fiorentini, "First-principles prediction of structure, energetics, formation enthalpy, elastic constants, polarization, and piezoelectric constants of AlN, GaN, and InN: comparison of local and gradient-corrected density-functional theory," Phys. Rev. B, vol. 64, pp. 045208–045213, 2001
[8] D. Marcon, B. De Jaeger, S. Halder, N. Vranckx, G. Mannaert, M. Van Hove, and S. Decoutere, "Manufacturing challenges of GaN-on-Si HEMTs in a 200 mm CMOS fab, " IEEE Trans. Semiconductor Manufacturing, vol. 26, no. 3, pp. 361-367, Aug. 2013.
[9] Fabio Sacconi, Aldo Di Carlo, P. Lugli, Hadis Morkoc, "Spontaneous and piezoelectric polarization effects on the output characteristics of AlGaN/GaN heterojunction modulation doped FETs." IEEE Trans. Electron Devices, pp. 450-457, March 2001.
[10] Guillermo Gonzalez, University of Miami, "Microwave Transistor Amplifiers: Analysis and Design, 2nd Edition, " Prentice Hall, Inc. Published: 1997
[11] Yonghyun Shim, Member, IEEE, Jean-Pierre Raskin, Member, IEEE, César Roda Neve, Member, IEEE, and Mina Rais-Zadeh, Senior Member, IEEE, "RF MEMS Passives on High-Resistivity Silicon Substrates," IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS, VOL. 23, NO. 12, DECEMBER 2013.
[12] G. M. Rebei, T. Guan-Leng, and J. S. Hayden, "RF MEMS phase shifters: Design and applications, " IEEE Microw. Mag., vol. 3, no. 2, pp. 72–81, Jun. 2002.
[13] Y. Shim, Z. Wu, and M. Rais-Zadeh, “A high-performance continuously tunable MEMS bandpass filter at 1 GHz,” IEEE Trans. Microw. Theory Tech., vol. 60, no. 8, pp. 2439–2447, Aug. 2012.
[14] M. Rais-Zadeh, J. Laskar, and F. Ayazi, “High performance inductors on CMOS-grade trenched silicon substrate,” IEEE Trans. Compon. Packag. Technol., vol. 31, no. 1, pp. 126–134, 2008.
[15] C. L. Goldsmith, Y. Zhimin, S. Eshelman, and D. Denniston, “Performance of low-loss RF MEMS capacitive switches,” IEEE Microw. Guided Wave Lett., vol. 8, no. 8, pp. 269–271, Aug. 1998.
[16] G. Lingpeng, J. K. O. Sin, L. Haitao, and X. Zhibing, “A fully integrated SOI RF MEMS technology for system-on-a-chip applications,” IEEE Trans. Electron Devices, vol. 53, no. 1, pp. 167–172, Jan. 2006.
[17] H. S. Gamble, B.M. Armstrong, S. J. N. Mitchell,Y. Wu,V. F. Fusco, and J. A. C. Stewart, "Low-loss CPW lines on surface stabilized highresistivity silicon, " IEEE Microw. Guided Wave Lett., vol. 9, no. 10, pp. 395–397, Oct. 1999.
[18] K. Ben Ali, C. Roda Neve, A. Gharsallah, and J.-P. Raskin, "Ultrawide frequency range crosstalk into standard and trap-rich high resistivity silicon substrates, " IEEE Trans. Electron Devices, vol. 58, no. 12, pp. 4258–4264, Dec. 2011.
[19] Yang Li, Cong Wang and Nam-Young Kim, "An Optimized Process of High-performance Integrated Passive Devices (IPDs) on SI-GaAs Substrate for RF Applications," 2013 Asia-Pacific Microwave Conference Proceedings.
[20] K. Zoschke, J. Wolf, M. Topper, O. Ehrmann, T. Fritzsch, K. Scherpinski, H. Reichl, and F. J. Schmuckle, “Fabrication of application specific integrated passive devices using wafer level packaging technologies,” IEEE Transactions on Advanced Packaging, vol. 30, no. 3, pp. 359-368, August 2007.
[21] V. Govind, P. Monajemi, L. Carastro, S. Lapushin, C. Russell, S. Dalmia, J. Vickers, V. Sundaram, and G. White, "Design of novel highly integrated passive devices for digital broadcasting satellite / 802.11 home networking solution in liquid crystal polymer (LCP) based organic substrates," 2006 IEEE MTT-S International Microwave Symposium Digest, pp. 1157-1160, June 2006.
[22] K. Liu, R. C. Frye, and R. Emigh, "Band-pass-filter with balun function from IPD technology, " IEEE Electronic Components and Technology Conference, pp. 718-723, May 2008.
[23] C. Wang, J. H. Lee, and N. Y. Kim, "High-performance integrated passive technology by advanced SI-GaAs-based fabrication for RF and microwave applications," Microwave and Optical Technology Letters, vol. 52, no. 3, pp. 618-623, March 2010.
[24] D. Lee, Y. H. Choi, M. Y. Jun, Y. D. Han, H. C. Yoon and S. Shoji, "Membrane sieve using stoichiometric and stress-reduced SiN/SiO/SiN multilayer films and applications to plasma separation," SENSORS, 2012 IEEE, 2012, pp. 1-4, doi: 10.1109/ICSENS.2012.6411404.
[25] R. Vetury, N. Q. Zhang, S. Keller, and U. K. 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.
[26] 池保勇，余志平，石秉学, "CMOS射频集成电路分析与设计," 清华大学出版社, 2006.
[27] K. Shiojima and N. Shigekawa, "Thermal stability of sheet resistance in AlGaN/GaN 2DEG structure, " phys. status solidi (c), vol. 0, no. 1, pp. 397-400, 2003, doi: 10.1002/PSSC.200390071.
[28] A. Messica, U. Meirav, and H. Shtrikman, "Refractory metal-based low-resistance ohmic contacts for submicron GaAs heterostructure devices," Thin Solid Films, vol. 257, no. 1, pp. 54-57, Feb. 1995, doi: 10.1016/0040-6090(94)06346-x.
[29] R. Gong, J. Wang, S. Liu, Z. Dong, M. Yu, C. P. Wen, Y. Cai, and B. Zhang, "Analysis of surface roughness in Ti/Al/Ni/Au ohmic contact to AlGaN/GaN high electron mobility transistors," Appl. Phys. Lett., vol. 97, no. 6, p. 062115, Aug. 2010, doi: 10.1063/1.3479928.
[30] 吳宏騏, "應用於微波/毫米波之矽基板氮化鎵無金高電子遷移率電晶體," 國立清華大學電子工程研究所碩士論文, 2020.