Comprehensive study on the deep depletion capacitance-voltage behavior for metal-oxide-semiconductor capacitor with ultrathin oxides

Abstract

The deep depletion behaviors at the structure of Si/SiO2 with various equivalent oxide thicknesses (EOTs) are comprehensively studied by magnified capacitance versus gate voltage (C-V) curves of metal-oxide-semiconductor (P-substrate) capacitors in this work. According to the correlation between inversion tunneling current and deep depletion, it was found that the initiation voltage of deep depletion phenomenon increases with EOT (2.8–3.1 nm). After the constant voltage stress, the early occurrence of initiation voltage of deep depletion is observed after oxide breakdown. In addition, the uniform area ratio concept is proposed for the electrical characterization of deep depletion via local depletion capacitance model. It was novel for the evaluation of interfacial property between dielectric and Si substrate.