Enhanced interface properties of diamond MOSFETs with Al2O3 gate dielectric deposited via ALD at a high temperature*
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2020-12-30 |
| Journal | Chinese Physics B |
| Authors | Yu Fu, Ruimin Xu, Xinxin Yu, Jianjun Zhou, Yuechan Kong |
| Citations | 4 |
Abstract
Section titled “Abstract”The interface state of hydrogen-terminated (C-H) diamond metal-oxide-semiconductor field-effect transistor (MOSFET) is critical for device performance. In this paper, we investigate the fixed charges and interface trap states in C-H diamond MOSFETs by using different gate dielectric processes. The devices use Al 2 O 3 as gate dielectrics that are deposited via atomic layer deposition (ALD) at 80 °C and 300 °C, respectively, and their C - V and I - V characteristics are comparatively investigated. Mott-Schottky plots (1/ C 2 - V G ) suggest that positive and negative fixed charges with low density of about 10 11 cm −2 are located in the 80-°C- and 300-°C deposition Al 2 O 3 films, respectively. The analyses of direct current (DC)/pulsed I - V and frequency-dependent conductance show that the shallow interface traps (0.46 eV-0.52 eV and 0.53 eV-0.56 eV above the valence band of diamond for the 80-°C and 300-°C deposition conditions, respectively) with distinct density (7.8 × 10 13 eV −1 ⋅cm −2 -8.5 × 10 13 eV −1 ⋅cm −2 and 2.2 × 10 13 eV −1 ⋅cm −2 -5.1 × 10 13 eV −1 ⋅cm −2 for the 80-°C- and 300-°C-deposition conditions, respectively) are present at the Al 2 O 3 /C-H diamond interface. Dynamic pulsed I - V and capacitance dispersion results indicate that the ALD Al 2 O 3 technique with 300-°C deposition temperature has higher stability for C-H diamond MOSFETs.