Improved single-event hardness of trench power MOSFET with a widened split gate

In this paper, a new 200V power MOSFET structure with a widened split gate trench to enhance single-event radiation hardness is proposed and studied by numerical simulation. The new MOSFET not only offers a great Rds(on)×Q _gd FOM, but also 55.3% wider radiation-hard Safe Operating Area (RHSOA) than the conventional trench MOSFET and split gate structure. The RHSOA advantage of the new device structure is due to the elimination of P-well region beneath the N+ source to almost completely suppress the influence of the parasitic NPN transistor, which is caused by the widened gate trench structure. In addition, this fabricating technology is compatible with the standard trench fabricating technology and the structure feature can be applied for all voltage ratings device with trench gate design. This new power MOSFET structure provides a great potential in space and aerospace power application.