Methods of forming a contact structure in a semiconductor device

摘要

A method of forming a contact structure in a semiconductor device includes forming an interlayer insulating layer containing impurities on a semiconductor substrate. The interlayer insulating layer is patterned to form a pad contact hole. The pad contact hole is filled with a conductive pad. Thermal oxidation annealing is then carried out to form an oxide layer on a top surface of the conductive pad and at an interface between the conductive pad and the interlayer insulating layer.