Charged Defect Quantification in Pt∕Al2O3∕In0.53Ga0.47As∕InP MOS Capacitors

Abstract

This work focuses on the separation and quantification of fixed bulk oxide charge, fixed charge at the dielectric-semiconductor interface and interface state charge components in the PtAl 2 O 3 In 0.53 Ga 0.47 As metal-oxide-semiconductor (MOS) system. The availability of atomic layer deposited Al 2 O 3 dielectrics over n- and p-type In 0.53 Ga 0.47 As with a range of well-controlled thickness values opens up an experimental route for the determination of the interface state density (D it ) independently of the total fixed oxide charge using capacitance-voltage measurements taken at 1 MHz and -50C. Low temperature forming gas annealing (350°C) significantly reduces the amount of fixed charge. The interface fixed charge is reduced from ∼ -8.5 × 10 12 cm -2 preanneal to ∼ -7.4 × 10 11 cm -2 postanneal and the bulk oxide charge is reduced from ∼1.4× 10 19 cm -3 preanneal to ∼5 × 10 18 cm -3 postanneal. The forming gas anneal also has a significant effect on the interface state charge, reducing its density from 1.3× 10 13 cm -2 preanneal to 4 ×10 12 cm -2 postanneal. © 2011 The Electrochemical Society.