Yabin Sun

Experimental study of bias dependence of pulsed laser-induced single-event transient in SiGe HBT

Abstract This work presents a comprehensive investigation of single-event transient (SET) in SiGe HBT induced by pulsed laser irradiation at different bias conditions. The impacts of collector voltage VCC and base voltage VB on SET are compared and discussed. Experimental results show that SET in SiGe HBT highly depends on the applied bias conditions during irradiation. The underlying physical mechanisms are analyzed in detail. It is found that the variation of collector transient current approximately satisfies an ideal exponential discharge law. The additional discharge path plays a significant role in collector charge collection and discharge time constant once the transistors arrive at the reverse-active mode.

Analytical Low Frequency NBTI Compact Modeling with H2 Locking and Electron Fast Capture and Emission

Besides reaction-diffusion theory explaining the generation and passivation of interface trap (ΔNIT), hole trapping/de-trapping in preexisting gate insulator traps and transient charge occupancy in ΔNIT are also combined to describe the characteristic of NBTI degradation. However, it is found that H2 locking effect and Electron Fast Capture/Emission play key roles in the NBTI degradation. In this paper, an analytical low frequency AC NBTI compact model has been proposed to accurately predict the shift in threshold voltage. Two fitting parameters (α and FFAST) have been introduced to account for the H2 locking and fast electron capture and emission. The comparison between the proposed model and the experimental data has been carried out, and the results show that our proposed can catch the kinetics of NBTI degradation under low frequency AC stress conditions.

Analytical long-term NBTI recovery model with slowing diffusivity and locking effect of hydrogen considered

Abstract The NBTI degradation caused by hole trapping in gate insulator process-related preexisting traps (∆ VHT) and in generated bulk insulator traps (∆ VOT) can recover in several seconds (< 10 s), whereas the long-term recovery is dominated by interface trap generation (∆ VIT). In this paper, various explanations of NBTI recovery have been reviewed and a compact analytical long-term NBTI recovery model in which the slowing down diffusivity and locking effect of H2 are involved has been derived. The triangular diffusion profile of H2 is approximated and the fitting coefficient ξ of slowing down diffusivity is related to the stress and recovery time. Our proposed model has been validated by the previous theories and numerical calculation. Moreover, the investigation of NBTI recovery on a 40-nm CMOS process has been experimentally carried out and the results show that our compact NBTI recovery model can describe the long-term recovery well.

Analytical capacitance model for 14 nm FinFET considering dual-k spacer*

The conformal mapping of an electric field has been employed to develop an accurate parasitic capacitance model for nanoscale fin field-effect transistor (FinFET) device. Firstly, the structure of the dual-layer spacers and the gate parasitic capacitors are thoroughly analyzed. Then, the Cartesian coordinate is transferred into the elliptic coordinate and the equivalent fringe capacitance model can be built-up by some arithmetical operations. In order to validate our proposed model, the comparison of statistical analysis between the proposed calculation and the 3D-TCAD simulation has been carried out, and several different material combinations of the dual-k structure have been considered. The results show that the proposed analytical model can accurately calculate the fringe capacitance of the FinFET device with dual-k spacers.