METHOD OF FORMING TRENCH TRANSISTOR AND PERTINENT TRENCH TRANSISTOR

摘要

PROBLEM TO BE SOLVED: To provide a method of forming a miniaturized trench gate MOS transistor.

SOLUTION: The method of forming a trench transistor includes steps of forming a trench 5 in a semiconductor substrate of a first conductivity type; forming a gate dielectric 20 in the trench 5; providing a first conductive filling material 30' in the trench 5 as gate electrode 30; forming a first source-and-drain region 4 by introducing impurities of a second conductive type into the surface of the substrate 1 alongside the trench 5; etching back the first conductive filling material 30' inside the trench 5 to set back to a given depth; introducing impurities of the second conductivity type into the surface of the substrate 1 in the interior of the trench 5 to form a second drain-and-source region 4'; forming insulating spacers 25, 25' on the first conductive filling material 30' inside the trench 5; and providing a second conductive filling material 30'' inside the trench 5 as an upper part of the gate electrode.

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