Vertical transistor with flashover protection

Abstract

Technologies are generally described for increase of spacing between source and drain regions of a vertical high voltage transistor without a significant corresponding increase in the die size. In some examples, active silicon (at drain potential) may be removed at an edge of the die in the scribe grid so that the active silicon is approximately below a surface of the edge termination formed by a region of deep dielectric filled trenches. The recessed drain region at the edge of the die may increase a flashover distance without appreciably increasing the die size. Thus, a distance between the recessed drain region and the surface source region may be increased by a combination of vertical and lateral spacing resulting in a smaller overall die size and smaller parasitic capacitances when operated with substantially the same operating voltage.