Patent ID: 7812409

Claim:
A trenched semiconductor power device comprising a plurality of trenched gates surrounding a plurality of transistor cells formed in a semiconductor substrate, wherein: said trenched gates surrounding said transistor cells as closed cells constituting substantially square-shaped cells with rounded corners; each of said closed cells further includes a circular trench contact disposed substantially in a central portion of said closed cells, penetrating through a source region surrounding said trenched gates and extending into a body region encompassing said source region; said circular trench contact comprises a hole opened from a top surface of said semiconductor substrate and is filled with a contact metal plug wherein sidewalls of said hole are surrounded by and in contact said source and body regions and said circular trench contact is separate from said trenched gates with said source region and body region disposed between a gate oxide lining of said trenched gates and all circumferential points of the circular trench contact; and said contact metal plug connected to a source metal disposed on top of said circular trench contact.