Charged defect quantification in PtAl₂O₃In _0.53Ga_0.47AsInP MOS capacitors

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 PtAl₂O₃In _0.53Ga_0.47As metal-oxide-semiconductor (MOS) system. The availability of atomic layer deposited Al₂O₃ dielectrics over n- and p-type In_0.53Ga_0.47As 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 × 10¹² cm^-2 preanneal to ∼ -7.4 × 10¹¹ cm^-2 postanneal and the bulk oxide charge is reduced from ∼1.4× 10¹⁹ cm^-3 preanneal to ∼5 × 10¹⁸ cm^-3 postanneal. The forming gas anneal also has a significant effect on the interface state charge, reducing its density from 1.3× 10¹³cm^-2 preanneal to 4 ×10 ¹² cm^-2 postanneal.