此研究製作出魚鰭寬度(Fin width)分別為50nm、80nm、110nm 在藍寶石(Sapphire)基板上之氮化鋁鎵/氮化鎵(AlGaN/GaN)鰭式場效電晶體(FinFET)。透過直流電特性、脈衝電壓、高頻S參數分析比較元件參數。
當魚鰭寬度越小時，臨界電壓(Vth) 向正值靠近，符合理論值。同時此研究在魚鰭寬度越小時，輸出電流變小，連帶使得轉導值(gm)變小、次臨界值擺幅(S.S.)增大、電流截止頻率(fT)降低、最大增益頻率(fmax)降低，原因可能來自於過長的魚鰭長度，使源極電阻增加所致。
而魚鰭寬度減小時，單位表面積增加，連帶使得表面缺陷增加，可能因此形成漏電路徑，造成元件特性變差。
本實驗透過蒸鍍導電層，使電子束微影可以用在不導電基板材料，並透過光罩設計減少電子束微影的曝光時間及微影成本，使得不導電基板之奈米級研究變得更加可行。

Three types of AlGaN / GaN fin-shaped field effect transistors (FinFETs) on sapphire substrate, with fin widths (Wfin) of 50nm, 80nm, and 110nm, have been fabricated. Each device have been characterized by DC characteristics, pulse voltage, and high frequency S-parameters. The threshold voltages of each device shift toward positive value as the fin width decreases, which is correspond with the theoretical value. However, the narrorer fin width gives to smaller output power, which leads to smaller transconductance (gm), larger sub-threshold swing (S.S.), slower cutoff frequency (fT) and maximum gain frequency (fmax). The reason may be that the influence of source resistance (Rs), which enhances when fin length (Lfin) increases. When the fin width decreases, the unit surface area and surface defects increase, forming leakage paths, which causes the deterioration of the device characteristics. In this experiment, nano-scaled fin width of FinFETs on sapphire substrate was fabricate, it will be more feasible to develop nano-level research on non-conductive substrates.

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