| 摘要 |
A recess gate of a semiconductor device and a method for forming the same are provided to increase a channel length of the recess gate by forming the recess gate on a dual bulb-type groove. A semiconductor substrate(200) is etched to form a first groove(H1). A spacer layer is formed on the whole surface of the substrate on which the first groove is formed, so that substrate parts at edges of both sides on a lower surface of the first groove are selectively exposed. The substrate parts at both edges on the lower surface of the first groove exposed by the spacer layer are etched to form a second groove(H2) at a side of the lower surface of the first groove. A third groove(H3) is symmetrically formed with respect to the second groove at another side on the lower surface of the first groove. The spacer layer is removed. A groove for a recess gate is comprised of the first, second, and third grooves. A gate dielectric(212) is formed on the substrate surface on which the groove for a recess gate is formed. A gate conductive layer(214) is formed on the gate dielectric to gap-fill the groove for a recess gate. The gate conductive layer and the gate dielectric are etched.
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