Affiliation:
1. Institute of Microelectronics
2. Sichuan University
Abstract
The reliability issue of threshold voltage (Vgs(th)) still exists in Silicon carbide (SiC) based metal-oxide-semiconductor-field-effect-transistors (MOSFETs). In this paper, the threshold voltage instability of 4H-SiC MOSFET is deeply studied through Silvaco TCAD simulation. This work mainly investigates the instability (shift) of the Vgs(th) affected by interface states (interface traps), near interface traps, and mobile ions. The results display that the effect of near interface traps on the Vgs(th) shift is greater than that of interface traps. The electron capture ability is related to the energy level of the traps. With the energy level increasing, the Vgs(th) shift increases firstly and then decreases. The peak energy level is related to the trap position and trap density. Furthermore, the effect of the mobile ions in the oxide layer on the Vgs(th) shift is limited. However, when moving to the SiC/SiO2 interface, they will greatly impact the Vgs(th) and affect the device performance seriously.
Publisher
Trans Tech Publications, Ltd.
Subject
Mechanical Engineering,Mechanics of Materials,General Materials Science
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