An electrical contact structure and a method for forming the electrical contact structure are provided. The method includes forming a thin film material layer on a substrate, forming a first barrier layer on the thin film material layer and forming a metal layer on the first barrier layer. The method further includes patterning the metal layer to form a metal pattern, forming a spacer on a sidewall of the metal pattern and covering a portion of the first barrier layer. The method further includes etching the first barrier layer, wherein the portion of the first barrier layer located under the spacer is not completely etched. The method further includes removing the spacer and exposing the sidewall of the metal pattern to form an electrical contact structure on the thin film material layer, wherein the first barrier layer has a protrusion part exceeding the sidewall of the metal pattern.