Liquid crystal display apparatus and manufacturing method thereof

Abstract

A liquid crystal apparatus includes a TFT array substrate which includes gate wirings having a gate electrode, source wirings having a source electrode, a thin film transistor having the gate electrode, a semiconductor layer, the source electrode, and a drain electrode, an interlayer insulating film provided above the thin film transistor and the gate and source wirings, a transparent pixel electrode having a first transparent conductive film connected to the drain electrode through a contact hole, and put into contact with a surface of a insulating substrate through a pixel opening provided in a gate insulating film and the interlayer insulating film, a reflective pixel electrode made of an Al-alloy connected to the drain electrode, and a second transparent conductive film formed on the reflective electrode. The second transparent conductive film has a same pattern shape as the reflective pixel electrode and a thickness thereof is at least 5 nm.

1 . A method of manufacturing a liquid crystal display apparatus, comprising:
 a first step of forming a first metal film on an insulating substrate and of forming a plurality of gate wirings including a gate electrode by performing patterning through a first photolithography step;   a second step of forming, after the first step, a first insulating film, a semiconductor layer, and an ohmic contact layer, and of patterning the semiconductor layer and the ohmic contact layer through a second photolithography step to be left at least on a part on which a thin film transistor is formed;   a third step of forming, after the second step, a second metal film, and of performing patterning through a third photolithography step to form a drain electrode and a plurality of source wirings including a source electrode;   a fourth step of forming, after the third step, an interlayer insulating film including a second insulating film and an organic film, of performing patterning through a fourth photolithography step to form a contact hole in the interlayer insulating film above the drain electrode, and of forming a pixel opening by partly opening the interlayer insulating film and the first insulating film to partially expose a surface of the insulating substrate;   a fifth step of forming, after the fourth step, a first transparent conductive film, and of performing patterning through a fifth photolithography step to form a transparent pixel electrode to be electrically connected to the drain electrode through the contact hole, and to be put into contact with a surface of the insulating substrate through the pixel opening; and   a sixth step of forming, after the fifth step, a third metal film and forming a second transparent conductive film on the third metal film, and of patterning the third metal film and the second transparent conductive film through a sixth photolithography step using a same mask pattern to form a reflective pixel electrode electrically connected to the drain electrode through the first transparent conductive film in the contact hole and to form a second transparent conductive film having a same pattern shape as that of the reflective pixel electrode,   wherein in the fifth step, the second transparent conductive film is formed so that a thickness of the second transparent conductive film is equal to or more than 5 nm, and   in the sixth photolithography step in the sixth step, the third metal film and the second transparent conductive film are collectively wet-etched by using a same etchant.   
   
   
       2 . The method of manufacturing a liquid crystal display apparatus according to  claim 1 ,
 wherein in the fifth step, the second transparent conductive film is formed to have a thickness that is equal to or more than 5 nm and is equal to or less than 15 nm.   
   
   
       3 . The method of manufacturing a liquid crystal display apparatus according to  claim 1 ,
 wherein the reflective pixel electrode is formed to have a thickness that is equal to or more than 50 nm and is equal to or less than 200 nm.   
   
   
       4 . The method of manufacturing a liquid crystal display apparatus according to  claim 2 ,
 wherein the reflective pixel electrode is formed to have a thickness that is equal to or more than 50 nm and is equal to or less than 200 nm.