New determination method of arbitrary energy distribution of traps in metal–oxide–semiconductor field effect transistor

We have developed a highly sensitive method, thermally stimulated voltage recovery (TSVR), to investigate traps responsible for the threshold voltage shift (ΔVth) in gate oxides of metal–oxide–semiconductor field effect transistors (MOSFETs). TSVR provides the contribution of traps with energy level Et to ΔVth just after trapping events [ΔVthi(Et)]. We applied TSVR to stressed MOSFETs with SiO2 gate oxides. The traps with several Et were observed and ΔVthi(Et) showed significant dependence on the gate length, reflecting the influence of fabrication processes on traps.

► We developed thermally stimulated voltage recovery method (TSVR).
► TSVR can detect traps in gate insulators of MOSFETs.
► TSVR can provide energy of traps and their contribution to a threshold voltage shift.
► We applied TSVR to MOSFETs and confirmed its validity.
► We elucidated significant dependence of traps on their gate length.