Power MOSFET with metal filled deep sinker contact for CSP

摘要

A method of forming an IC including a power semiconductor device includes providing a substrate having an epi layer thereon with at least one transistor formed therein covered by a pre-metal dielectric (PMD) layer. Contact openings are etched from through the PMD into the epi layer to form a sinker trench extending to a first node of the device. A metal fill material is deposited to cover a sidewall and bottom of the sinker trench but not completely fill the sinker trench. A dielectric filler layer is deposited over the metal fill material to fill the sinker trench. An overburden region of the dielectric filler layer is removed stopping on a surface of the metal fill material in the overburden region to form a sinker contact. A patterned interconnect metal is formed providing a connection between the interconnect metal and metal fill material on the sidewall of the sinker trench.