HIGH SPEED POWER TRANSISTOR AND FABRICATION METHOD THEREOF

摘要

PURPOSE: A high speed power transistor and a fabrication method thereof are provided to reduce the resistance of a trench gate electrode and thus to increase an operation speed of the device by reducing a transfer delay time of an electrical signal by the reduction of the resistance. CONSTITUTION: A gate is formed by stacking a polysilicon and a metal in a trench. A lightly doped N-type silicon epi layer(2) is grown on a heavily doped N-type silicon substrate(1). After growing a thin oxide on the epi layer, an N-type impurity ion is implanted to form a body(3) and is annealed. A nitride film pattern is formed on the oxide and a heavily doped N-type impurity ion is implanted and a well(4) is formed by a high temperature annealing as growing the oxide on the revealed part. And a source junction(5) is formed by implanting a heavily doped P-type impurity ion. After removing the oxide and forming an insulation film(11), a trench is formed by dry-etching the insulation film and the source junction and the body and a part of the epi layer on the gate region. After forming a gate oxide(12) in the trench, a doped polysilicon(14) and a metal(15) are stacked. After etching a part of the polysilicon and the metal, an interlayer insulation film(13) is deposited. And, an electrode contacted to each of the source junction and the metal is formed by etching the interlayer insulation film selectively, and a drain is formed under the silicon substrate.