Reliability improvements in SOI-like MOSFET with ESD and self-heating effect
A new structure of N-type Silicon-on-insulator (SOI)-Like Bulk Silicon (N-SL-BS) metal–oxide–semiconductor field-effect transistor (MOSFET) is proposed to improve the reliability of SOI MOSFET mainly with regards to their self-heating effect and electro-static discharge (ESD) events based on two-dimensional numerical simulation. The new device employs p/n–/p + structure on Si, in which the n-layer is made of Si carbide (SiC), a wide bandgap material. The built-in electric field fully depletes the n-SiC layer and forms an SOI-like feature with a p + layer underneath. Simulations are first implemented in self-heating conditions, to investigate their drain current and temperature ramping. More importantly, ESD pulses assuming the human body model are applied to test their response and observe which device was first to fail using an I–V curve and hole current density distribution. Results show that the new device exhibits superior reliability when compared with a traditional SOI MOSFET. The avalanche breakdown voltage improves nearly 33% and the highest temperature of the global device is more than three times lower than that of an SOI MOSFET subjected to ESD pulses with a peak current of 7 mA.
