Methods for fabricating semiconductor devices

A method for fabricating a semiconductor device, the method comprising:

• providing a substrate including an active region formed therein;
• forming a conductive layer on the substrate;
• forming a lower mask layer covering the conductive layer;
• forming a plurality of hardmask layers on the lower mask layer, the hardmask layers having island shapes spaced apart from each other in a first direction and in a second direction crossing the first direction;
• forming a plurality of upper mask patterns having island shapes spaced apart from each other in the first and second directions on the lower mask layer to expose portions of the lower mask layer, the exposed potions of the lower mask layer each having an island shape surrounded by the upper mask pattern and the hardmask layer;
• etching the exposed portions of the lower mask layer to expose portions of the conductive layer, the exposed portions of the conductive layer each having an island shape;
• and
• etching the exposed portions of the conductive layer to form a plurality of contact holes that expose portions of the active region, the exposed portions of the active region each having an island shape.

A method for fabricating a semiconductor device, the method comprising:

• forming a plurality of active regions having parallel line shapes extending in a zigzag fashion along a direction across a substrate;
• stacking a conductive layer and a lower mask layer on the substrate;
• forming a plurality of hardmask layers each having an island shape on the lower mask layer;
• forming a plurality of upper mask patterns on the lower mask layer, the plurality of upper mask patterns having island shapes arranged to expose portions of the lower mask layer;
• patterning the lower mask layer by an etching process using the hardmask layers as an etch mask to form a plurality of lower mask patterns each having an island shape;
• and
• patterning the conductive layer by an etching process using the lower mask patterns as an etch mask to form contact holes each exposing a portion of the active region.