US Patent 8003540 Method for manufacturing semiconductor device

A method for manufacturing a semiconductor device includes forming an underlying layer over a semiconductor substrate; forming a hard mask layer over the underlying layer; forming first etch patterns over the hard mask layer; forming second etch patterns between the first photoresist patterns; etching the hard mask layer using the first and second etch patterns as an etch mask to form a hard mask pattern; and etching the underlying layer using at least the hard mask pattern. The first and second etch patterns are formed on the same layer.