Patent ID: 6777341
Filing Date: 2004-08-17
Classification: H01L

Abstract:
A method forming self-aligned contacts, comprising the steps of:forming gate stacks in a series of parallel stripes on a semiconductor substrate; forming gate spacers on the sidewalls of the gate stacks; forming conductive film pads to serve as buried contact pads between the gate spacers; forming a first interlayer insulation layer over the conductive film pads and the gate stacks; forming bit line stacks, in a series of parallel stripes skewed relative to the gate stacks, on the first interlayer insulation layer; forming bit line spacers on the sidewalls of the bit line stacks; forming a second interlayer insulation layer on the first interlayer insulation layer in such a way that upper surfaces of the bit line stacks are exposed; forming a photoresist film pattern, on the second interlayer insulation layer, in the form of laterally spaced apart stripes of photoresist extending parallel to the gate stacks, the photoresist film pattern exposing segments of the bit line stacks and exposing portions of the second interlayer insulation layer located directly above respective ones of the conductive film pads, respectively; etching the second interlayer insulation layer and the first interlayer insulation layer using the photoresist film pattern, the bit line stacks and the bit line spacers as etching masks to form contact holes exposing the conductive film pads by; and filling the contact holes with a conductive material to form conductive plugs contacting the conductive film pads.