Thin film transistor and method of manufacturing thin film transistor

Abstract

A method of manufacturing a low-cost thin film transistor of minimized variations in performances, as well as the thin film transistor produced thereby. A thin film transistor manufacturing method including the steps of: forming a gate electrode on a substrate; forming a gate insulation layer on the gate electrode; forming a semiconductor layer by coating the gate insulation layer with a semiconductor material; forming a repellent layer having an electrode material-repellent characteristic on the semiconductor layer; applying light from the surface of the substrate where there is no gate electrode, thereby removing the semiconductor layer and the repellent layer by sublimation, except for the portion protected against light by the gate electrode; and dropping the fluid electrode material on the repellent layer remaining on the substrate so that the fluid electrode material is separated by the repellent layer, whereby the source electrode and the drain electrode are formed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1(1-a) to 1(9-b) are explanatory diagrams showing a method of manufacturing a thin film transistor of the present invention;

FIGS. 2( a) to 2(c) are explanatory diagrams showing an irradiation process in the Example 2;

FIGS. 3(1-a) to 3(6-b) are explanatory diagrams showing the method of manufacturing the TFT in the Example 3;

FIGS. 4( a) to 4(c) are explanatory diagrams showing an irradiation process in the Example 5;

FIGS. 5( a) to 5(e) are explanatory diagrams showing the method of manufacturing the TFT in the Example 6;

FIGS. 6( a) to 6(e) are explanatory diagrams showing the method of manufacturing the TFT in the Example 7; and

FIGS. 7( a) to 7(e) are explanatory diagrams showing the method of manufacturing the TFT in the Example 8.

Claims

1. A method of manufacturing a thin film transistor which includes at least a gate electrode, a semiconductor layer, a source electrode and a drain electrode on a transmissive substrate, the method comprising the steps of: forming the gate electrode on the substrate;forming a gate insulation layer on the gate electrode;forming the semiconductor layer on the gate insulation layer;forming a repellent layer on the semiconductor layer, the repellent layer being repellent to a fluid electrode material;a removing step for removing a part of the semiconductor layer and the repellent layer other than an area shaded from the light with the gate electrode, by irradiating light from an opposite surface to a surface on which the gate electrode is formed; andforming the source electrode and the drain electrode by dropping the fluid electrode material on the repellent layer and dividing the fluid electrode material by the repellent.

2. The method of manufacturing the thin film transistor of claim 1, wherein the semiconductor layer is formed by an inkjet method.

3. The method of manufacturing the thin film transistor of claim 1, wherein the repellent layer is formed by an inkjet method.

4. The method of manufacturing the thin film transistor of claim 1, wherein the repellent layer includes a self assembled monolayer.

5. The method of manufacturing the thin film transistor of claim 1, wherein in the removing step, removing a part of the repellent layer by irradiating light also from a surface of the substrate on which the repellent layer is formed, an amount of the light being enough to remove the repellent layer and not enough to remove the semiconductor layer.

6. The method of manufacturing the thin film transistor of claim 1, wherein the removing step comprising the steps of: a first irradiation step for irradiating light on an area of the substrate on which the source electrode is to be formed; anda second irradiation step for irradiating light on an area of the substrate on which the drain electrode is to be formed,wherein in the first irradiation step, the light is irradiated at an angle at which a traveling direction of the light is declined to the source electrode side with respect to a vertical direction to the substrate, and in the second irradiation step, a light irradiated at an angle at which a traveling direction of the light is declined to the drain electrode side with respect to a vertical direction to the substrate.

7. The method of manufacturing the thin film transistor of claim 1, wherein the removing step comprising the steps of: a first irradiation step of irradiating light on an area of the substrate on which the source electrode is to be formed; anda second irradiation step of irradiating light on an area of the substrate on which the drain electrode is to be formed,wherein in the first irradiation step, the light is irradiated at an angle at which a traveling direction of the light is declined to the drain electrode side with respect to a vertical direction to the substrate, and in the second irradiation step, a light irradiated at an angle at which a traveling direction of the light is declined to the source electrode side with respect to a vertical direction to the substrate.

8. The method of manufacturing the thin film transistor of claim 1, wherein the removing step comprising the steps of: a first irradiation step of irradiating light on a first side of the gate electrode, on which the source electrode or the train electrode is formed; anda second irradiation step of irradiating light on a second side of the gate electrode, on which the source electrode or the drain electrode is formed,wherein in the first irradiation step, the light is irradiated at an angle at which a traveling direction of the light is declined to the second side with respect to a vertical direction to the substrate, and in the second irradiation step, a light is irradiated at an angle at which a traveling direction of the light is declined to the first side with respect to a vertical direction to the substrate.

9. The method of manufacturing the thin film transistor of claim 1, wherein the removing step comprising the steps of: a first irradiation step of irradiating light on a first side of the gate electrode, on which the source electrode or the train electrode is formed; anda second irradiation step of irradiating light on a second side of the gate electrode, on which the source electrode or the drain electrode is formed,wherein in the first irradiation step, the light is irradiated at an angle at which a traveling direction of the light is declined to the first side with respect to a vertical direction to the substrate, and in the second irradiation step, a light is irradiated at an angle at which a traveling direction of the light is declined to the second side with respect to a vertical direction to the substrate.

10. The method of manufacturing the thin film transistor of claim 1, comprising the step of: forming an alignment layer on the gate insulation layer before forming the semiconductor layer and after forming the gate insulation layer.

11. A method of manufacturing a thin film transistor which includes at least a gate electrode, a semiconductor layer, a source electrode and a drain electrode on a transmissive substrate, the method comprising the steps of: forming the gate electrode on the substrate;forming a gate insulation layer on the gate electrode;forming the semiconductor layer on the gate insulation layer;forming a repellent layer on the semiconductor layer, the repellent layer being repellent to a fluid electrode material;removing the repellent layer and the semiconductor layer by irradiating light to form a repellent layer whose shape is the same as the gate electrode and to form a semiconductor layer whose shape is grater than the shape of the formed repellent layer; andforming the source electrode and the drain electrode.

12. A method of manufacturing a thin film transistor which includes at least a gate electrode, a semiconductor layer, a source electrode and a drain electrode on a transmissive substrate, the method comprising the steps of: forming the gate electrode on the substrate;forming a gate insulation layer on the gate electrode;forming the semiconductor layer on the gate insulation layer;forming a repellent layer on the semiconductor layer, the repellent layer being repellent to a fluid electrode material;removing a part of the repellent layer not shaded with the gate electrode and a part of the semiconductor layer not shaded with a photo mask pattern by irradiating light, which has an enough amount of light to remove the semiconductor layer, through the photo mask to cover the gate electrode, the photomask having the mask pattern which transmits light whose amount of light is enough to remove the repellent layer and not enough to remove the semiconductor layer when light strong enough to remove the semiconductor layer is irradiated to the photo mask; andforming the source electrode and the drain electrode.

13. A method of manufacturing a thin film transistor which includes at least a gate electrode, a semiconductor layer, a source electrode and a drain electrode on a transmissive substrate, the method comprising the steps of: forming the gate electrode on the substrate;forming a gate insulation layer on the gate electrode;forming the semiconductor layer on the gate insulation layer;forming a repellent layer on the semiconductor layer, the repellent layer being repellent to a fluid electrode material;irradiating light, which has an amount of light enough to remove the repellent layer and not enough to remove the semiconductor layer, from an opposite surface to a surface where the gate electrode is formed, and removing a part of the repellent layer not shaded with the gate electrode;irradiating light on the semiconductor layer through a photo mask and removing the semiconductor layer, the photo mask having a mask pattern to shade an area wider than the gate electrode and being disposed on a same side of the substrate as the semiconductor layer is formed; andforming the source electrode and the drain electrode.

14. A thin film transistor, comprising, a substrate;an gate electrode disposed on the substrate;a gate insulation layer disposed on the gate electrode;an alignment layer which is comprised of a self assembled monolayer and disposed on the insulation layer;a semiconductor layer disposed on the alignment layer;a repellent layer which is disposed on the semiconductor layer, and is comprised of a self assembled monolayer which is repellant to an electrode material for forming a source electrode and a drain electrode;a source electrode which is connected to the semiconductor layer; anda drain electrode which is connected to the semiconductor layer.