A method for a thin film transistor array panel includes forming a gate line and a pixel electrode on a substrate, forming a gate insulating layer covering the gate line, forming a data line including a source electrode and a drain electrode on the gate insulating layer, forming an interlayer insulating layer covering the data line and the drain electrode on the gate insulating layer, forming a first opening in the interlayer insulating layer, forming an organic semiconductor in the first opening, forming a passivation layer on the organic semiconductor and the interlayer insulating layer, and forming a second opening in the interlayer insulating layer to expose the pixel electrode.