Electrical Properties of Diamond MISFETs with Submicron-Sized Gate on Boron-Doped (111) Surface
- PDF / 1,158,408 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 67 Downloads / 211 Views
0891-EE10-22.1
Electrical Properties of Diamond MISFETs with Submicron-Sized Gate on Boron-Doped (111) Surface Takeyasu Saito1, Kyung-ho Park1, Kazuyuki Hirama2, Hitoshi Umezawa１, Mitsuya Satoh2, Hiroshi Kawarada2, Zhi-Quan Liu3, Kazutaka Mitsuishi3 and Hideyo Okushi1 1 Diamond Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan 2 Department of Electrical Engineering and Bioscience, Waseda University, Shinjyuku-ku, Tokyo 169-8555, Japan 3 National Institute for Materials Science, 3-13, Sakura, Tsukuba 305-0003, Japan ABSTRACT An H-terminated-surface conductive layer of B-doped diamond on a (111) surface was used to fabricate a metal insulator semiconductor field effect transistor (MISFET) using CaF2, SiO2 or Al2O3 gate insulators and a Cu-metal stacked gate. For a CaF2 gate, the maximum measured drain current (Idmax) was 240 mA/mm and the maximum transconductance (gm) was 70 mS/mm, and the cut-off frequency of 4 GHz was obtained. For a SiO2 gate, Idmax and gm were 75 mA/mm and 24 mS/mm, respectively, and for an Al2O3 gate, these characteristics were 86 mA/mm and 15 mS/mm, respectively. These values are among the highest reported DC and RF characteristics for a diamond homoepitaxial (111) MISFET. INTRODUCTION Diamond semiconductor devices show promise under high-power, high-frequency, and harsh environmental (radiation, high temperature, toxic chemicals) applications [1]. However, it is difficult due to the deep acceptor or donor level to realize a low-resistivity semiconductive diamond [2, 3]. Consequently, diamond device technology is limited to devices that have a p-type H-terminated surface conductive layer [4]. Metal semiconductor FETs (MESFETs) and MISFETs on H-terminated surfaces on (100) substrates have attained cut-off frequencies over 20 GHz with a gate length of 200 nm [5, 6]. However, most of such works has involved the (100)-oriented surface. In contrast, electrical properties of H-terminated as well as oxidized (111) surfaces have been recently reported, clarifying that oxidized (111) surfaces are conductive [7, 8]. Based on the reported resistivity of oxidized (111) surfaces, compared with an H-terminated (100) surface, an oxidized (111) surface has potential and practical advantage for
0891-EE10-22.2
use in harsh environments without an increase in dehydrogenation-induced resistivity. Thus, oxidized (111) surfaces might be the key for realizing diamond metal oxide semiconductor FETs (MOSFETs) to achieve stable operation. Development of diamond MOSFETs will require screening of gate oxides based on, for example, gap states, leakage current, and breakdown voltage [9], and should include process optimization to suppress the damage of H-terminated surfaces on diamond during oxide growth. In the current study, a p-type surface conductive diamond (111) layer employed MISFETs with a submicron-sized gate length using CaF2, SiO2 or Al2O3 gate insulators. Properties for the devices were measured, such as drain current (Id) and gate curre
Data Loading...
Recommend Documents
Electrical Stabilization of Diamond Mis Interface and Misfets by Ultrahigh-Vacuum Process
153 62 2MB
Reaction Processes at the Initial Stage of Diamond Nucleation on the Surface of Si(111)
169 76 422KB
