Patent ID: 8039347
Filing Date: 2011-10-18
Classification: H01L

Abstract:
1. A method for manufacturing a semiconductor device, comprising the steps of: etching a semiconductor substrate to form pillar structures in the semiconductor substrate; forming a first sacrificial layer over portions of the semiconductor substrate between the pillar structures so that upper portions of the pillar structures are exposed and lower portions of the pillar structures are covered; forming spacers over sidewalls of the upper portions of the pillar structures; removing the first sacrificial layer; forming a metal layer so that the metal layer surrounds the pillar structures which has the spacers; forming a second sacrificial layer on the metal layer to substantially fill the lower portions of between the pillar structures; etching primarily the metal layer to expose the spacers; removing the second sacrificial layer; and forming gates that substantially surround the portions of the pillar structures under the spacers by etching the etched metal layer.