Patent ID: 8685803
Filing Date: 2014-04-01
Classification: G02F,H01L

Abstract:
1. A method for producing a semiconductor device, the semiconductor device comprising: a substrate; a thin film transistor formed on the substrate; and a terminal portion for electrically connecting the thin film transistor to external wiring; the thin film transistor including: the terminal portion including: within a first opening provided in the first insulating film and the second insulating film, the second connecting portion is in contact with the first connecting portion; within a second opening provided in the passivation film, the third connecting portion is in contact with the second connecting portion; and the second connecting portion covers end faces of the first insulating film and the second insulating film within the first opening, but does not cover an end face of the passivation film within the second opening, and a part of the second connecting portion is located between the second insulating film and the passivation film, the method comprising: (A) a step of forming a conductive film for a gate line on a substrate, and patterning the conductive film to form a gate line and a first connecting portion; (B) a step of forming a first insulating film on the gate line and the first connecting portion; (C) a step of forming on the first insulating film an oxide semiconductor layer to become an active layer of a thin film transistor; (D) a step of forming a second insulating film covering the oxide semiconductor layer and the first insulating film; (E) a step of etching the first and second insulating films to form in the second insulating film an opening for forming a source contact and an opening for forming a drain contact by using the oxide semiconductor layer as an etchstop, such that the oxide semiconductor layer is exposed through the openings, and form a first opening in the second insulating film and the first insulating film, such that a surface of the first connecting portion is exposed through the first opening; (F) a step of forming a conductive film for source/drain electrodes on the second insulating film, and patterning the conductive film to form a source line which is in contact with the oxide semiconductor layer within the opening for forming a source contact, a drain electrode which is in contact with the oxide semiconductor layer within the opening for forming a drain contact, and a second connecting portion which is in contact with the first connecting portion within the first opening; (G) a step of forming a passivation film on the source line, the drain electrode, and the second connecting portion; (H) a step of forming a second opening in the passivation film, such that the second connecting portion is exposed through the second opening; and (I) a step of forming a third connecting portion on the passivation film, the third connecting portion being in contact with the second connecting portion within the second opening.