We derive analytical models of the excess carrier density distribution and the HPM(high-power microwave) upset susceptibility with dependence of pulse-width,which are validated by the simulated results and experimental data.Mechanism analysis and model derivation verify that the excess carriers dominate the current amplification process of the latch-up.Our results reveal that the excess carrier density distribution in P-substrate behaves as pulse-width dependence.The HPM upset voltage threshold V_p decreases with the incremental pulsewidth,while there is an inflection point which is caused because the excess carrier accumulation in the P-substrate will be suppressed over time.For the first time,the physical essence of the HPM pulse-width upset effect is proposed to be the excess carrier accumulation effect.Validation concludes that the V_p model is capable of giving a reliable and accurate prediction to the HPM upset susceptibility of a CMOS inverter,which simultaneously considers technology information,ambient temperature,and layout parameters.From the model,the layout parameter L_B has been demonstrated to have a significant impact on the pulse-width upset effect:a CMOS inverter with minor L_b is more susceptible to HPM,which enables us to put forward hardening measures for inverters that are immune from the HPM upset. We derive analytical models of the excess carrier density distribution and the HPM (high-power microwave) upset susceptibility with dependence of pulse-width, which are validated by the simulated results and experimental data. Mechanism analysis and model derivation verify that the excess carriers dominate the current amplification process of the latch-up. Our results reveal that the excess carrier density distribution in P-substrate behaves as pulse-width dependence. HPM upset voltage threshold V_p decreases with the incremental pulsewidth, while there is an an inflection point which is caused because the excess carrier accumulation in the P-substrate will be canceled over time. For the first time, the physical essence of the HPM pulse-width upset effect is proposed to be the excess carrier accumulation effect. Value concludes that the V_p model is capable of giving a reliable and accurate prediction to the HPM upset susceptibility of a CMOS inverter, which simultaneously considers tech nology information, ambient temperature, and layout parameters. From the model, the layout parameter L_B has been demonstrated to have a significant impact on the pulse-width upset effect: a CMOS inverter with minor L_b is more susceptible to HPM, which enables us to put forward hardening measures for inverters that are immune from the HPM upset.