Transistor and display device

• US 9,954,007 B2
• Filed: 04/27/2017
• Issued: 04/24/2018
• Est. Priority Date: 09/04/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Sasaki, Toshinari, Sakata, Junichiro, Tsubuku, Masashi
• Primary Examiner(s): Pham, Thanh V
• Application Number:
  US15/498,940
• Publication Number:
  US 20170294457A1
• Time in Patent Office: 362 Days
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 27/1248 with a particular composition or shape of the interlayer dielectric specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 29/24 including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22 including organic materials H10K99/00
• CPC Class Codes: H01L 29/42356 Disposition, e.g. buried gate electrode H01L29/42324 and H01L29/4234 take precedence
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• CPC Class Codes: H01L 29/458 for thin film silicon, e.g. source or drain electrode
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/78606 with supplementary region or layer in the thin film or in the insulated bulk substrate supporting it for controlling or increasing the safety of the device H01L29/78642, H01L29/78645 take precedence
• 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
• CPC Class Codes: H01L 29/78693 the semiconducting oxide being amorphous
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/1216 the pixel elements being capacitors
• CPC Class Codes: H10K 59/123 Connection of the pixel electrodes to the thin film transistors [TFT]

Abstract

It is an object to manufacture a highly reliable display device using a thin film transistor having favorable electric characteristics and high reliability as a switching element. In a bottom gate thin film transistor including an amorphous oxide semiconductor, an oxide conductive layer having a crystal region is formed between an oxide semiconductor layer which has been dehydrated or dehydrogenated by heat treatment and each of a source electrode layer and a drain electrode layer which are formed using a metal material. Accordingly, contact resistance between the oxide semiconductor layer and each of the source electrode layer and the drain electrode layer can be reduced; thus, a thin film transistor having favorable electric characteristics and a highly reliable display device using the thin film transistor can be provided.

Claims

1. A display device comprising:

a first gate electrode;

a first gate insulating layer over the first gate electrode;

an oxide semiconductor layer over the first gate insulating layer and including a channel formation region;

a first insulating layer over the oxide semiconductor layer, wherein the first insulating layer overlaps with at least an end portion of the oxide semiconductor layer;

a source electrode and a drain electrode each over the first insulating layer and electrically connected to the oxide semiconductor layer;

a second insulating layer over and in contact with the oxide semiconductor layer;

a first color filter layer over the first insulating layer;

a third insulating layer over the first color filter layer; and

a light-emitting element over the first color filter layer with the third insulating layer interposed between the light-emitting element and the first color filter layer, wherein the light-emitting element comprises a first electrode, a second electrode, and an EL layer between the first electrode and the second electrode,

wherein the oxide semiconductor layer comprises indium, gallium, and zinc.

2. The display device according to claim 1, wherein the second insulating layer is positioned over the source electrode and the drain electrode.

3. The display device according to claim 1, comprising:

a first oxide conductive layer between the source electrode and the oxide semiconductor layer; and

a second oxide conductive layer between the drain electrode and the oxide semiconductor layer.

4. The display device according to claim 1, wherein the first color filter is positioned over the second insulating layer.

5. The display device according to claim 1, comprising a fourth insulating layer between the light-emitting element and the third insulating layer.

6. The display device according to claim 1, wherein the oxide semiconductor layer is amorphous.

7. The display device according to claim 1, wherein the third insulating layer comprises a light-transmitting resin.

8. The display device according to claim 1, wherein the third insulating layer is a protective insulating layer.

9. A display device comprising:

a first gate electrode;

a first gate insulating layer over the first gate electrode;

an oxide semiconductor layer over the first gate insulating layer and including a channel formation region;

a first insulating layer over the oxide semiconductor layer, wherein the first insulating layer overlaps with at least an end portion of the oxide semiconductor layer;

a source electrode and a drain electrode each over the first insulating layer and electrically connected to the oxide semiconductor layer;

a second insulating layer over and in contact with the oxide semiconductor layer;

a first conductive layer over the second insulating layer;

a first color filter layer over the first insulating layer;

a third insulating layer over the first color filter layer; and

a light-emitting element over the first color filter layer with the third insulating layer interposed between the light-emitting element and the first color filter layer, wherein the light-emitting element comprises a first electrode, a second electrode, and an EL layer between the first electrode and the second electrode,

wherein the oxide semiconductor layer comprises indium, gallium, and zinc.

10. The display device according to claim 9, wherein the second insulating layer is positioned over the source electrode and the drain electrode.

11. The display device according to claim 9, comprising:

a first oxide conductive layer between the source electrode and the oxide semiconductor layer; and

a second oxide conductive layer between the drain electrode and the oxide semiconductor layer.

12. The display device according to claim 9, wherein the first color filter is positioned over the second insulating layer.

13. The display device according to claim 9, comprising a fourth insulating layer between the light-emitting element and the third insulating layer.

14. The display device according to claim 9, wherein the oxide semiconductor layer is amorphous.

15. The display device according to claim 9, wherein the third insulating layer comprises a light-transmitting resin.

16. The display device according to claim 9, wherein the third insulating layer is a protective insulating layer.

17. The display device according to claim 9, wherein the first conductive layer is configured to be applied with a potential same as the first gate electrode.

18. The display device according to claim 9, wherein the first conductive layer is configured to be applied with a potential different from the first gate electrode.