Properties of c-axis-aligned crystalline indium–gallium–zinc oxide field-effect transistors fabricated through a tapered-trench gate process. (22nd March 2016)

• Record Type: Journal Article
• Authors: Asami, Yoshinobu; Kurata, Motomu; Okazaki, Yutaka; Higa, Eiji; Matsubayashi, Daisuke; Okamoto, Satoru; Sasagawa, Shinya; Moriwaka, Tomoaki; Kakehata, Tetsuya; Yakubo, Yuto; Kato, Kiyoshi; Hamada, Takashi; Sakakura, Masayuki; Hayakawa, Masahiko; Yamazaki, Shunpei
• Is Part Of: Japanese journal of applied physics. Volume 55:Number 4(2016:Apr.)Supplement 4
• Publication Date: 2016-03-22
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/JJAP.55.04EG09
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: To achieve both low power consumption and high-speed operation, we fabricated c -axis-aligned crystalline indium–gallium–zinc oxide (CAAC-IGZO) field-effect transistors (FETs) with In-rich IGZO and common IGZO ( in atomic ratio) active layers through a simple process using trench gates, and evaluated their characteristics. The results confirm that 60-nm-node IGZO FETs fabricated through a 450 °C process show an extremely low off-state current below the detection limit (at most 2 × 10 −16 A) even at a measurement temperature of 150 °C. The results also reveal that the FETs with the In-rich IGZO active layer show a higher on-state current than those with the common IGZO active layer and have excellent frequency characteristics with a cutoff frequency and a maximum oscillation frequency of up to 20 and 6 GHz, respectively. Thus, we demonstrated that CAAC-IGZO FETs with trench gates are promising for achieving both low power consumption and high-speed operation.