A method for fabricating a fine pattern in a semiconductor device includes forming a first polymer layer and a second polymer layer over an etch target layer. The second polymer layer is patterned at a first substrate temperature. The first polymer layer is etched at a second substrate temperature using an etch gas that does not include oxygen (O2). The first polymer layer is etched using the patterned second polymer layer as an etch mask. The etch target layer is then etched using the etched first polymer layer and the etched second polymer layer as an etch mask.