Three-dimensional device simulation of random telegraph noise spectroscopy with Coulomb energy variation of the trap in high-k gate oxide

Abstract

The random telegraph noise (RTN) time constants, capture (τc) and emission (τe) times, have been extensively used to identify the trap position in the gate oxide by comparing the measured τc-over-τe ratio with the Shockley–Read–Hall (SRH) statistics. However, various factors have been shown to affect the accuracy of the extracted trap depth from the SRH-type models, such as three-dimensional (3D) device electrostatics, atomistic doping, metal gate granularity, and Coulomb energy variation (CEV) of the trap. Focusing on CEV in this work, we assume the trap in gate oxide can be regarded as a floating island and then numerically studied the CEV of the trap with 3D drift-diffusion simulation. Analyzing the simulation data, the extracted trap depth without considering CEV in the SRH statistics are quantitatively compared with the data involved CEV.