Normally-off hydrogen-terminated diamond field effect transistor with yttrium gate. (May 2021)

• Record Type: Journal Article
• Authors: Zhang, Minghui; Wang, Wei; Fan, Shuwei; Chen, Genqiang; Abbasi, Haris Naeem; Lin, Fang; Wen, Feng; Zhang, Jingwen; Bu, Renan; Wang, Hong-Xing
• Is Part Of: Carbon. Volume 176(2021)
• Page Start: 307
• Page End: 312
• Publication Date: 2021-05
• Subjects: Hydrogen-terminated diamond -- Field effect transistor -- Normally-off -- Yttrium; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2021.01.121
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: The normally-off Yttrium (Y) gate hydrogen-terminated (H-terminated) diamond field effect transistor (FET) with 5 nm Al2 O3 dielectric layer has been successfully fabricated and evaluated in this work. The threshold voltage is extracted to be - 0.21 V at drain source voltage of −10 V, and the normally-off mode should be caused by the low work function of Y. The saturated drain current (IDSsat ) is - 16.14 mA/mm obtained at gate voltage (VGS ) of - 2.5 V with 4 μm gate length and 100 μm gate width. The value of I DSsat I DSmax is relatively high compared with other normally-off H-terminated diamond FETs at the same gate voltage, and this is ascribed to the well-preserved two-dimensional hole gas channel. The maximum transconductance of the fabricated device is 7.97 mS/mm. The current on/off ratio is about 7 orders of magnitude with a subthreshold swing of 150 mV/dec. The maximum effective mobility is 233.08 cm 2 /V. The results contribute to the development of normally-off H-terminated diamond FETs significantly.