Texas Instruments Corporation

Tianping Lv

Yunlong Liu

Ho Lin

Frank Alexander Baiocchi

Furen Lin

Lark Liu

Peter Lin

Hong Yang

Yufei Xiong

Sheng Zou

Qiuling Jia

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.

Power MOSFET with metal filled deep sinker contact for CSP

A planar gate power MOSFET includes a substrate having a semiconductor surface doped a first conductivity type, a plurality of transistor cells (cells) including a first cell and at least a second cell each having a gate stack over a body region. A trench has an aspect ratio of &#x3e;3 extending down from a top side of the semiconductor surface between the gate stacks providing a source contact (SCT) from a source doped a second conductivity type to the substrate. A field plate (FP) is over the gate stacks that provides a liner for the trench. The trench has a refractory metal or platinum-group metal (PGM) metal filler within. A drain doped the second conductivity type is in the semiconductor surface on a side of the gate stacks opposite the trench.

Power MOSFET with metal filled deep source contact

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Tianping Lv