Semiconductor device, liquid crystal display device equipped with semiconductor device, and process for production of semiconductor device

Abstract

Disclosed is an electrode film which is not peeled from an oxide semiconductor or an oxide thin film, and from which copper atoms are not diffused into the oxide semiconductor or the oxide thin film. In the electrode film, an electrode layer comprises a high-density barrier film (37) that is a Cu-Mg-Al thin film and a copper thin film (38), wherein an oxide semiconductor or an oxide thin film is contacted with the high-density barrier film (37). When the high-density barrier film (37) contains 0.5 to 5 at% inclusive of magnesium and 5 to 15 at% inclusive of aluminum relative to the total number (100 at%) of atoms of copper, magnesium and aluminum, the high-density barrier film (37) can have both adhesion properties and barrier properties. The electrode layer is suitable, because a source electrode layer (51) and a drain electrode layer (52) are contacted with the oxide semiconductor layer (34). A stopper layer (36) comprising an oxide may be provided on an under layer of the electrode layer.

Description

technical field [0001] The present invention relates to the field of wiring films used in minute semiconductor devices, and in particular to the technical field of electrode layers in contact with oxide semiconductors. Background technique [0002] In electrical products manufactured in recent years, such as flat panel displays (FPD, Flat Panel Display) and thin-film solar cells, it is necessary to arrange transistors uniformly on a wide substrate. Therefore, it is necessary to use a semiconductor layer ( Hydrogenated) amorphous silicon, etc. [0003] Amorphous silicon can be formed at low temperature and has no adverse effect on other materials, but has the disadvantage of low electron mobility. An oxide semiconductor that can be formed at low temperature and form a high-mobility thin film into a large-area substrate has attracted attention. [0004] On the other hand, in recent years, low-resistance copper films have been used on electrodes and wiring of transistors in se...

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Problems solved by technology

[0008] Copper thin film is difficult to dry etch, and wet etching is generally used, but the etchant for copper thin film is different from that of auxiliary film, so it is not possible to etch a wiring film with a double-layer structure of auxiliary film and copper thin film in one etching process

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