Patent ID: 7745290

Claim:
A method of forming a semiconductor device, the method comprising: forming sacrificial bars on a semiconductor substrate; patterning the sacrificial bars to form sacrificial islands on the semiconductor substrate; forming a device isolation layer to fill a space between the sacrificial islands; selectively removing the sacrificial islands to expose the semiconductor substrate below the sacrificial islands; and anisotropically etching the exposed semiconductor substrate using the device isolation layer as an etch mask to form a recessed channel region; wherein before forming the sacrificial islands: forming a mask layer to fill a space between the sacrificial bars; and planarizing the mask layer to expose top surfaces of the sacrificial bars, wherein the mask layer comprises a material having an etch selectivity with respect to the sacrificial bars; and wherein forming the sacrificial islands comprises: patterning the mask layer and the sacrificial bars in a direction substantially perpendicular to a major axis of the sacrificial bars to form the sacrificial islands and mask patterns disposed therebetween; and etching the exposed surfaces of the sacrificial islands using the mask patterns as etch masks to partially expose the top surface of the semiconductor substrate between the mask patterns.