Reliability assessment of integrated power transistors: Lateral DMOS versus vertical DMOS

The total safe operating area of both lateral and vertical integrated DMOS power transistors is evaluated. The electrical, hot carrier and thermal safe operating area of both devices types is investigated, and a comparison is made. It is found that the vertical DMOS exhibits a superior hot carrier and electrical safe operating area, mainly being due to the absence of a field oxide dot in the device drift region. The thermal safe operating area of LDMOS and VDMOS is identical.