MANUFACTURING METHOD OF THIN FILM TRANSISTOR USING OXIDE SEMICONDUCTOR

• US 20100140612A1
• Filed: 05/28/2008
• Published: 06/10/2010
• Est. Priority Date: 05/31/2007
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Omura, Hideyuki, Hayashi, Ryo
• Granted Patent: US 8,193,045 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

A manufacturing method of a thin film transistor having at least a gate electrode, a gate insulation film, an oxide semiconductor layer, a first insulation film, a source electrode, a drain electrode, and a second insulation film on a substrate, including: forming the gate electrode on the substrate; forming the gate insulation film on the gate electrode; forming a semiconductor layer including amorphous oxide on the gate insulation film; patterning the gate insulation film; patterning the oxide semiconductor layer; reducing the oxide semiconductor layer in resistance by forming the first insulation film on the oxide semiconductor layer in the atmosphere not including an oxidized gas; patterning the first insulation film and forming a contact hole between the source electrode and the drain electrode and the oxide semiconductor layer; forming a source electrode layer and a drain electrode layer in the oxide semiconductor layer through the contact hole; forming the source electrode and the drain electrode through the contact hole and allowing the first insulation film to be exposed; patterning the exposed first insulation film and allowing a channel region of the oxide semiconductor layer to be exposed; and increasing the channel region in resistance by forming the second insulation film on the surface including the channel region of the oxide semiconductor layer in the atmosphere including an oxidized gas.

Claims

1. A manufacturing method of a thin film transistor having at least a gate electrode, a gate insulation film, an oxide semiconductor layer, a first insulation film, a source electrode, a drain electrode, and a second insulation film on a substrate, including:

forming the gate electrode on the substrate;

forming the gate insulation film on the gate electrode;

forming a semiconductor layer including amorphous oxide on the gate insulation film;

patterning the gate insulation film;

patterning the oxide semiconductor layer;

reducing the oxide semiconductor layer in resistance by forming the first insulation film on the oxide semiconductor layer in the atmosphere not including an oxidized gas;

patterning the first insulation film and forming contact holes between the source electrode and the drain electrode and the oxide semiconductor layer;

forming a source electrode layer and a drain electrode layer in the oxide semiconductor layer through the contact holes;

forming the source electrode and the drain electrode by patterning and allowing the first insulation film to be exposed;

patterning the exposed first insulation film and allowing a channel region of the oxide semiconductor layer to be exposed; and

increasing the channel region in resistance by forming the second insulation film on the surface including the channel region of the oxide semiconductor layer in the atmosphere including an oxidized gas.

5. The manufacturing method of the thin film transistor according to claim 1, wherein, as the atmosphere including the oxidized gas, an O₂/Ar mixed gas is used, and its mixed ratio is 10 volume % or more.

6. The manufacturing method of the thin film transistor according to claim 1, wherein the amorphous oxide is amorphous oxide including at least one of In, Zn, and Sn or amorphous oxide including In, Zn, and Ga.

7. The manufacturing method of the thin film transistor according to claim 1, wherein the first insulation film is an amorphous oxide insulator.

8. The manufacturing method of the thin film transistor according to claim 1, wherein the second insulation film is an amorphous oxide insulator, and contains desorption gas, observed as O₂⁺ and O⁺ by temperature programmed desorption analysis, of 3.8×

10¹⁹ pcs/cm³ or more.

9. A thin film transistor manufactured by the manufacturing method according to claim 1.

10. A display device, wherein the electrode of a display element is connected with a source or drain electrode of the thin film transistor according to claim 9.

11. The display device according to claim 10, wherein the display element is an electroluminescent element.

12. The display device according to claim 10, wherein the display element is a liquid crystal cell.

13. The display device according to claim 10, wherein a plurality of the display elements and the thin film transistors are two-dimensionally disposed on the substrate.

2. A manufacturing method of a thin film transistor having at least a gate electrode, a gate insulation film, an oxide semiconductor layer, a first insulation film, a source electrode, a drain electrode, and a second insulation film on a substrate, including:

forming the gate electrode on the substrate;

forming the gate insulation film on the gate electrode;

forming a semiconductor layer including amorphous oxide on the gate insulation film;

patterning the gate insulation film;

patterning the oxide semiconductor layer;

reducing the oxide semiconductor layer in resistance by forming the first insulation film on the oxide semiconductor layer in the atmosphere not including an oxidized gas;

patterning the first insulation film and allowing the channel region of the oxide semiconductor layer to be exposed;

increasing the channel region in resistance by forming the second insulation film on the channel region and the first insulation film in the atmosphere including an oxidized gas;

forming contact holes between the source electrode and the drain electrode and the region reduced in resistance of the oxide semiconductor layer below the first insulation film in the stacked first and second insulation films;

forming a source electrode layer and a drain electrode layer in the region reduced in resistance of the oxide semiconductor layer through the contact holes; and

patterning the source electrode and the drain electrode.

3. A manufacturing method of a thin film transistor having at least a gate electrode, an oxide semiconductor layer, a first insulation film, a source electrode, a drain electrode, and a second insulation film on a substrate, including:

forming a semiconductor layer including amorphous oxide on a substrate;

patterning the oxide semiconductor layer;

reducing the oxide semiconductor layer in resistance by forming the insulation film on the oxide semiconductor layer in the atmosphere not including an oxidized gas;

patterning the first insulation film and forming contact holes between a source electrode and a drain electrode and the oxide semiconductor layer;

forming a source electrode layer and a drain electrode layer in the oxide semiconductor layer through the contact holes;

forming the source electrode and the drain electrode by patterning and allowing the first insulation film to be exposed;

patterning the exposed first insulation film and allowing the channel region of the oxide semiconductor layer to be exposed;

increasing the channel region in resistance by forming the second insulation film on the surface including the channel region of the oxide semiconductor layer in the atmosphere including an oxidized gas; and

forming the gate electrode on the second insulation film.

4. A manufacturing method of a thin film transistor having at least a gate electrode, an oxide semiconductor layer, a first insulation film, a source electrode, a drain electrode, and a second insulation film on a substrate, including:

forming a semiconductor layer including amorphous oxide on a substrate;

patterning the oxide semiconductor layer;

reducing the oxide semiconductor layer in resistance by forming the first insulation film on the oxide semiconductor layer in the atmosphere not including an oxidized gas;

patterning the first insulation film and allowing the channel region of the oxide semiconductor layer to be exposed;

increasing the channel region in resistance by forming the second insulation film on the surface including the channel region of the oxide semiconductor layer in the atmosphere including an oxidized gas;

forming contact holes between the source electrode and the drain electrode and the region reduced in resistance of the oxide semiconductor layer below the first insulation film on the stacked first and second insulation films;

forming a source electrode layer and a drain electrode layer as well as a gate electrode layer in the oxide semiconductor layer through the contact holes; and

forming the source electrode, the drain electrode, and the gate electrode by patterning.