High-k ZrO2/Al2O3 bilayer on hydrogenated diamond - Band configuration, breakdown field, and electrical properties of field-effect transistors
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2016-09-23 |
| Journal | Journal of Applied Physics |
| Authors | Jiangwei Liu, Meiyong Liao, Masataka Imura, Yasuo Koide |
| Institutions | National Institute for Materials Science |
| Citations | 30 |
Abstract
Section titled āAbstractāA band configuration of a high-k ZrO2/Al2O3 bilayer on hydrogenated diamond (H-diamond), a breakdown field (EB) of the ZrO2/Al2O3 bilayer, and an effect of gate-drain distance (dG-D) on electrical properties of ZrO2/Al2O3/H-diamond metal-insulator-semiconductor field-effect transistors (MISFETs) have been investigated. The Al2O3 and ZrO2 layers are successively deposited on H-diamond by atomic layer deposition (ALD) and sputtering-deposition (SD) techniques, respectively. The thin ALD-Al2O3 buffer layer with 4.0 nm thickness plays a role in protecting the H-diamond surface from being damaged by the plasma discharge during SD-ZrO2 deposition. The ZrO2/Al2O3 heterojunction has a type I band structure with valence and conduction band offsets of 0.6 Ā± 0.2 and 1.0 Ā± 0.2 eV, respectively. The valence band offset between ZrO2 and H-diamond is deduced to be 2.3 Ā± 0.2 eV. The EB of the ZrO2/Al2O3 bilayer is measured to be 5.2 MV cmā1, which is larger than that of the single ZrO2 layer due to the existence of the ALD-Al2O3 buffer layer. The dependence of dG-D on drain-source current maximum (IDS,max), on-resistance (RON), threshold voltage (VTH), and extrinsic transconductance maximum (gm,max) of the MISFETs has been investigated. With increasing dG-D from 4 to 18 Ī¼m, the absolute IDS,max decreases from 72.7 to 40.1 mA mmā1, and the RON increases linearly from 83.3 Ā± 5 to 158.7 Ā± 5 Ī© mm. Variation of VTH values of around 1.0 V is observed, and the gm,max is in the range between 8.0 Ā± 0.1 and 13.1 Ā± 0.1 mS mmā1.