Patent ID: 7491603

Claim:
A method of forming a semiconductor device, the method comprising: forming pad layer patterns exposing a region of a semiconductor substrate; forming a channel-portion hole in the semiconductor substrate between the pad layer patterns and extending downward from a main surface of the semiconductor substrate, a lower portion and an upper portion of a sidewall of the channel-portion hole being covered with a channel-portion trench pad layer and a channel french spacer layer, respectively; performing an etching process on the channel trench spacer layer and the channel-portion trench pad layer to form a channel-portion trench pad and a channel trench spacer respectively on the lower portion and the upper portion of the sidewall of the channel-portion hole, thereby exposing the semiconductor substrate with a predetermined width along the sidewall of the channel-portion hole between the channel trench spacer and the channel-portion trench pad; performing an epitaxial process on the semiconductor substrate having the channel trench spacer and the channel-portion trench pad to form a channel-portion layer, the channel-portion layer being formed on the channel-portion trench pad to fill the lower portion of the channel-portion hole with a thickness about as much as the predetermined width of the exposed semiconductor substrate; removing the pad layer pattern and the channel trench spacer from the semiconductor substrate by using the channel-portion layer as an etching stop layer; and sequentially forming a word line insulating layer pattern and a word line pattern disposed on the channel-portion layer and the main surface of the semiconductor substrate to fill the channel-portion hole.