Liquid crystal display and fabricating method comprising a hydrophilic buffer layer having a thickness of 10Å to 50Å
View Patent ↗A liquid crystal display and a method of fabricating such a liquid crystal display wherein a buffer layer having a hydrophilic property is formed at normal (atmospheric) pressure on the exposed surface of a hydrophobic organic passivation layer. The buffer layer improves the adhesion between an exposed surface and a subsequently formed electrode layer. The buffer layer is beneficially formed from an oxide layer that is induced on the surface of the buffer layer using UV radiation having a wavelength of 100 to 200 nm. Such a buffer layer can eliminate vacuum fabrication and shorten the fabrication time of the liquid crystal display.
1. A method of fabricating a liquid crystal display having a thin film transistor with a gate electrode, a gate insulating film, an active layer, an ohmic contact layer, a source electrode, and a drain electrode on a transparent substrate, said method comprising:
forming an organic passivation layer over the transparent substrate and over the thin film transistor;
defining a contact hole through the organic passivation layer to expose the drain electrode;
irradiating the organic passivation layer with ultraviolet rays having a wavelength in a range between about 100 nm and about 200 nm to form a hydrophilic buffer layer having a thickness of 10 Å to 50 Å; and
forming a pixel electrode over the hydrophilic buffer layer and in the contact hole such that the pixel electrode contacts the drain electrode via the contact hole and such that the pixel electrode adheres to the hydrophilic buffer layer.
2. The method according to claim 1 , wherein the step of forming an organic passivation layer produces an organic passivation layer having a low dielectric constant.
3. The method according to claim 1 , wherein the step of irradiating the organic passivation layer occurs at normal processing pressure.
4. The method according to claim 1 , wherein the step of irradiating the organic passivation layer occurs at atmospheric pressure.
5. The method according to claim 1 , wherein the step of irradiating the organic passivation layer produces a buffer layer comprised of an oxide.
6. The method according to claim 1 , wherein the step of forming a pixel electrode produces a transparent pixel electrode.
7. A liquid crystal display, comprising:
a substrate;
a thin film transistor on said substrate, said thin film transistor including a gate electrode, a gate insulating film, an active layer, a source electrode, and a drain electrode;
an organic passivation layer over the thin film transistor;
a hydrophilic buffer layer having a thickness of 10 Å to 50 Å over said passivation layer, the buffer layer formed by irradiating the organic passivation layer with ultraviolet rays having a wavelength in a range between about 100 nm and about 200 nm; and
an electrode over said buffer layer.
8. A liquid crystal display according to claim 7 , wherein said buffer layer has a hydrophilic property.
9. A liquid crystal display according to claim 8 , further including a contact hole through said passivation layer and that exposes said drain electrode, wherein said electrode electrically contacts said drain electrode via the contact hole.
10. A liquid crystal display according to claim 9 , wherein said electrode is a pixel electrode.
11. A liquid crystal display according to claim 10 , wherein said pixel electrode is transparent.
12. A liquid crystal display according to claim 11 , wherein said pixel electrode is comprised of indium.
13. A liquid crystal display according to claim 7 , wherein said substrate is transparent.
14. A liquid crystal display according to claim 7 , wherein said organic passivation layer is comprised of β-staggered-divinyl-siloxane-benzocyclobutene.
15. A liquid crystal display according to claim 7 , wherein said organic passivation layer is comprised of an acrylic organic compound.
16. A liquid crystal display according to claim 7 , wherein said organic passivation layer is comprised of perfluorocyclobutane.
17. A liquid crystal display according to claim 7 , wherein said buffer layer is an oxide.
18. A liquid crystal display according to claim 7 , wherein said organic passivation layer is hydrophobic.