A formation method of contact structure is provided to reduce the short failure between a contact and a conductive structure in a self-align contact etch process by laminating a first protective layer pattern and a second protective layer pattern, which has different an etching ratio from the first protective layer pattern, on the conductive structure. A formation method of contact structure includes the step of forming conductive structures including a conductive layer pattern(106) on a substrate and a first protective layer pattern formed on the conductive layer pattern or lateral side thereof; the step of forming an interlayer dielectric layer pattern(104) which fills the gap between the conductive structures; the step of forming a recess part by etching partially the upper side of the first protective layer pattern; the step of forming a second protective layer pattern(120) with a material which has higher etching ratio than the first protective layer pattern; the step of forming a contact plug which is electrically connected with the substrate by passing through the interlayer dielectric layer pattern between the first and second protective layer patterns. The conductive structure is a word line structure or a bit line structure.
