A method of forming a self-aligned contact and manufacturing method of a semiconductor device with a self-aligned contact

In a method for forming a self-aligned contact gates are formed on a semiconductor substrate in a striped pattern. are bit lines in a striped pattern which extends crosswise over the gates are formed. The bit lines are isolated from each other by a first intermediate insulating layer. Next, a second interlayer insulating layer between the bit lines is formed, and a photoresist layer pattern is formed on the second intermediate insulation layer. The photoresist layer pattern is used to form contact openings extending between the gates down to the line pads. The contact openings are to form conductive plugs that contact the line pads filled. The photoresist layer pattern is in the form of a series of strips, which extend parallel to the gates are formed. The photoresist strip place segments of the bit lines and the portions of the second interlayer insulating layer is exposed, which are arranged directly above the power layer pads, thereby providing a sufficient alignment margin is secured, and a large underlying surface to be etched to form the contact openings is exposed. For forming a semiconductor device, a third interlayer insulating layer, an etch stop layer, an oxide layer and a hard mask layer are formed on the conductive plugs. Next, a second ...