Method of forming a lamination film pattern and improved lamination film pattern
View Patent ↗In a method of forming an electrically conductive lamination pattern, an insulating film is formed on a surface of a chromium-containing bottom layer, before an aluminum-containing top layer is formed over the insulating film, so that the insulating film separates the aluminum-containing top layer from the chromium-containing bottom layer. A first selective wet etching process is carried out for selectively etching the aluminum-containing top layer with a first etchant. A second selective wet etching process is carried out for selectively etching the chromium-containing bottom layer with a second etchant in the presence the insulating film which suppresses a hetero-metal-contact-potential-difference between the chromium-containing bottom layer and the aluminum-containing top layer during the second selective wet etching process.
1. An electrically conductive lamination pattern structure including:
a chromium-containing bottom layer;
an insulating film extending over a surface of said chromium-containing bottom layer; and
an aluminum-containing top layer extending over said insulating film, so that said insulating film separates said aluminum-containing top layer from said chromium-containing bottom layer,
wherein said aluminum-containing top layer is tapered in cross sectional elevation shape.
2. The structure as claimed in claim 1 , wherein edges of said chromium-containing bottom layer and said insulating film are aligned to or positioned inside of a tapered edge of said aluminum-containing top layer.
3. The structure as claimed in claim 1 , wherein said aluminum-containing top layer has a taper angle of at most approximately 60 degrees.
4. The structure as claimed in claim 1 , wherein said insulating film comprises an oxide film formed by an oxidation process to said surface of said chromium-containing bottom layer.
5. The structure as claimed in claim 1 , wherein said insulating film has a thickness in the range of 5 nanometers to 50 nanometers.
6. The structure as claimed in claim 1 , wherein said chromium-containing bottom layer comprises one of a chromium layer and a chromium alloy layer, and said aluminum-containing top layer comprises one of an aluminum layer or an aluminum alloy layer.
7. The structure as claimed in claim 1 , wherein said electrically conductive lamination pattern structure is formed over a substrate for a liquid crystal display panel.
8. The structure as claimed in claim 7 , wherein said substrate is a thin film transistor substrate for said liquid crystal display panel.