1 nm equivalent oxide thickness in Ga2 O3 (Gd2 O3) In0.2 Ga0.8 As metal-oxide-semiconductor capacitors
Journal
Applied Physics Letters
Journal Volume
92
Journal Issue
17
Date Issued
2008
Author(s)
Abstract
An equivalent oxide thickness about 1 nm for Ga2 O3 (Gd2 O3) (GGO) on In0.2 Ga0.8 As has been achieved by employing a thin in situ deposited 3 nm thick Al2 O3 protection layer. The dual gate oxide stacks of the Al2 O3 GGO (33, 20, 10, 8.5, and 4.5 nm)/ In0.2 Ga0.8 AsGaAs metal-oxide-semiconductor (MOS) capacitors remain amorphous after rapid thermal annealing up to 800-850 °C, accompanied with atomically sharp smooth oxide/semiconductor interfaces. Well behaved capacitance-voltage (C-V) curves of the MOS diodes have shown sharp transition from depletion to accumulation with small flatband voltage (1.1 V for Au metal gate and 0.1 V for Al), and weak frequency dispersion (1.5%-5.4%) between 10 and 500 kHz at accumulation capacitance. Low leakage current densities [3.1× 10-5 and 2.5× 10-9 A cm2 at V= Vfb +1 V for Al2 O3 (3 nm) GGO (4.5 and 8.5 nm)], a high dielectric constant around 14-16 of GGO for all tested thicknesses, and a low interfacial density of states (Dit) in the low 1011 cm-2 eV-1 have also been accomplished. © 2008 American Institute of Physics.
SDGs
Type
journal article