Display device and method of manufacturing the same
A display device includes: a substrate; an active layer on the substrate; and a gate electrode on the active layer. The gate electrode includes a first metal layer, a second metal layer on the first metal layer, and a third metal layer on the second metal layer. The first metal layer includes aluminum, the second metal layer includes transparent conductive oxide, and the third metal layer includes a niobium-titanium alloy.
1 . A display device comprising:
a substrate;
an active layer on the substrate; and
a gate electrode on the active layer, the gate electrode comprising a first metal layer, a second metal layer on the first metal layer, and a third metal layer on the second metal layer,
wherein the first metal layer comprises aluminum, the second metal layer comprises transparent conductive oxide, and the third metal layer comprises a niobium-titanium alloy.
2 . The display device of claim 1 , wherein a content of titanium in the niobium-titanium alloy is 50 at % or less.
3 . The display device of claim 1 , wherein the first metal layer comprises an aluminum alloy.
4 . The display device of claim 3 , wherein a content of materials other than aluminum in the aluminum alloy is 0.1 at % or less.
5 . The display device of claim 1 , wherein the second metal layer comprises indium gallium zinc oxide.
6 . The display device of claim 1 , wherein the second metal layer comprises indium zinc oxide.
7 . The display device of claim 1 , wherein the first metal layer has a thickness in a range of 2500 Å to 3500 Å.
8 . The display device of claim 1 , wherein each of the second metal layer and the third metal layer has a thickness in a range of 200 Å to 300 Å.
9 . The display device of claim 1 , wherein the active layer comprises polycrystalline silicon.
10 . A display device comprising:
a substrate;
an active layer on the substrate, the active layer comprising polycrystalline silicon; and
a gate electrode on the active layer, the gate electrode comprising a first metal layer, a second metal layer on the first metal layer, and a third metal layer on the second metal layer,
wherein the first metal layer comprises aluminum, the second metal layer comprises a niobium-titanium alloy, and the third metal layer comprises a transparent conductive oxide.
11 . The display device of claim 10 , wherein a content of titanium in the niobium-titanium alloy is 50 at % or less.
12 . The display device of claim 10 , wherein the first metal layer comprises an aluminum alloy.
13 . The display device of claim 12 , wherein a content of materials other than aluminum in the aluminum alloy is 0.1 at % or less.
14 . The display device of claim 10 , wherein the third metal layer comprises indium gallium zinc oxide.
15 . The display device of claim 10 , wherein the third metal layer comprises indium zinc oxide.
16 . The display device of claim 10 , wherein the first metal layer has a thickness in a range of 2500 Å to 3500 Å, and
wherein each of the second metal layer and the third metal layer has a thickness in a range of 200 Å to 300 Å.
17 . A method of manufacturing a display device, the method comprising:
forming an active layer on a substrate;
forming a preliminary first metal layer on the active layer, the preliminary first metal layer comprising aluminum;
forming a preliminary second metal layer on the preliminary first metal layer, the preliminary second metal layer comprising a transparent conductive oxide;
forming a preliminary third metal layer on the preliminary second metal layer, the preliminary third metal layer comprising a niobium-titanium alloy; and
forming a gate electrode by patterning the preliminary first metal layer, the preliminary second metal layer, and the preliminary third metal layer.
18 . The method of claim 17 , further comprising:
forming an insulating layer on the gate electrode;
forming contact holes in the insulating layer to respectively expose at least a portion of the active layer and the gate electrode; and
concurrently cleaning the portion of the active layer and the gate electrode exposed by the contact holes.
19 . The method of claim 17 , wherein the forming the gate electrode comprises:
forming a third metal layer by dry etching the preliminary third metal layer;
forming a second metal layer overlapping the third metal layer by wet etching the preliminary second metal layer; and
forming a first metal layer overlapping the second metal layer by dry etching the preliminary first metal layer.
20 . The method of claim 17 , wherein a content of titanium in the niobium-titanium alloy is 50 at % or less.