[15p-4F-1~25] 6.2 Carbon-based thin films

▲ [15p-4F-4] Hydrogenated Black Diamond FET with high voltage breakdown of 1.8kV

〇(D)M.Syamsul N.S.B.¹, Kitabayashi Yuya¹, Daisuke Matsumura¹, Toshiki Saito¹, Hiroshi Kawarada¹ (1.Waseda Univ.)

Keywords:Diamond FET,Black diamond

Less attention and further studies involved on black polycrystalline diamond since the early year of 2000 even though promising characteristics were demonstrated by William et al. and his team shows that the carrier concentration and mobility values similar to both white polycrystalline diamond and single crystal material. [1]. Highest breakdown voltage is recently discovered in 2014 by Hitoshi Umezawa et al. and his team is 1530V with gate-drain length, LGD of 30 µm [2]. In this paper, C-H black diamond were fabricated by the implementation of a wide gate-drain length up to 20 µm device structure with C-H bonded channel to achieve high breakdown voltages. Au/Ti source and drain contacts were deposited followed with annealing in H2 forming TiC layer underneath [3]. Exposure of H2 plasma was then performed and followed with device isolation by exposing to Oxygen plasma. Finally, Al2O3 was deposited as a gate insulator and the passivation layer for a C-H bonded surface channel and a metal gate electrode Aluminum was deposited. With room temperature I-V measurements, this device exhibits perfect device characteristics, pinch-off and saturation region IDS-VDS with maximum current density of 1.1mmA/mm higher than any clean boron doped polycrystalline diamond. The maximum breakdown voltage (VBmax) is 1802V at a gate-drain distance (LGD) of 18μm. Thus, C-H Black diamond currently is the highest value of VBmax reported for a diamond FET so far better than any single crystalline and clean polycrystalline diamond device satisfying VB,max/LGD = 100V/μm (1MV/cm).
References
[1] RB Jackman and CE Nebel, Physica Status Solidi, 193 (2002) 577
[2] Umezawa .H, Matsumoto.T, Shikata.S-I, IEEE Electron Device Letters, Vol. 35 Issue 11, (2014), 1112-1114
[3] Y. Jingu, K. Hirama, and H. Kawarada, IEEE Transaction on Electron Devices, 57(5), (2010) 966-972