SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

• US 20130187153A1
• Filed: 01/22/2013
• Published: 07/25/2013
• Est. Priority Date: 01/25/2012
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: YAMAZAKI, Shunpei, KOEZUKA, Junichi, OKAZAKI, Kenichi, IKEYAMA, Terumasa, TOCHIBAYASHI, Katsuaki
• Granted Patent: US 9,293,589 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 21/385 using diffusion into or out of a solid from or into a solid phase, e.g. a doped oxide layer
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• 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 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

A highly reliable semiconductor device including a transistor using an oxide semiconductor is provided. In a semiconductor device including a bottom-gate transistor including an oxide semiconductor layer, a first insulating layer is formed in contact with the oxide semiconductor layer, and an oxygen doping treatment is performed thereon, whereby the first insulating layer is made to contain oxygen in excess of the stoichiometric composition. The formation of the second insulating layer over the first insulating layer enables excess oxygen included in the first insulating layer to be supplied efficiently to the oxide semiconductor layer. Accordingly, the highly reliable semiconductor device with stable electric characteristics can be provided.

Claims

1. A method for manufacturing a semiconductor device, comprising the steps of:

forming a gate electrode;

forming a gate insulating layer over the gate electrode;

forming an oxide semiconductor layer over the gate insulating layer, the oxide semiconductor layer overlapping with the gate electrode;

forming a source electrode and a drain electrode over the oxide semiconductor layer;

forming a first insulating layer over the source electrode and the drain electrode, the first insulating layer being in contact with part of the oxide semiconductor layer;

performing an oxygen doping treatment over the first insulating layer; and

forming a second insulating layer over the first insulating layer,

wherein the second insulating layer is thicker than the first insulating layer.

2. The method for manufacturing a semiconductor device according to claim 1, wherein the thickness of the first insulating layer is more than 10 nm and less than 100 nm.

3. The method for manufacturing a semiconductor device according to claim 1, further comprising the step of removing impurities of the part of the oxide semiconductor layer after forming the source electrode and the drain electrode.

4. The method for manufacturing a semiconductor device according to claim 1, further comprising the step of forming a third insulating layer over the second insulating layer.

5. The method for manufacturing a semiconductor device according to claim 4, wherein the third insulating layer comprises aluminum oxide.

6. The method for manufacturing a semiconductor device according to claim 4, wherein the third insulating layer has a resistivity less than or equal to 1×

10¹⁹ Ω

·

m.

7. A method for manufacturing a semiconductor device, comprising the steps of:

forming a gate electrode;

forming a gate insulating layer over the gate electrode;

forming an oxide semiconductor layer over the gate insulating layer, the oxide semiconductor layer overlapping with the gate electrode;

forming a source electrode and a drain electrode over the oxide semiconductor layer;

forming a first insulating layer over the source electrode and the drain electrode, the first insulating layer being in contact with part of the oxide semiconductor layer;

performing an oxygen doping treatment over the first insulating layer; and

forming a second insulating layer over the first insulating layer,

wherein the second insulating layer is a metal oxide layer formed by forming a metal layer over the first insulating layer and performing an oxygen doping treatment thereon, and

wherein the second insulating layer is thicker than the first insulating layer.

8. The method for manufacturing a semiconductor device according to claim 7, wherein the thickness of the first insulating layer is more than 10 nm and less than 100 nm.

9. The method for manufacturing a semiconductor device according to claim 7, further comprising the step of removing impurities of the part of the oxide semiconductor layer after forming the source electrode and the drain electrode.

10. The method for manufacturing a semiconductor device according to claim 7, wherein the second insulating layer comprises aluminum oxide.

11. The method for manufacturing a semiconductor device according to claim 7, wherein the second insulating layer has a resistivity less than or equal to 1×

10¹⁹ Ω

·

m.

12. A semiconductor device comprising:

a gate electrode;

a gate insulating layer over the gate electrode;

an oxide semiconductor layer over the gate insulating layer, the oxide semiconductor layer overlapping with the gate electrode;

a source electrode and a drain electrode over the oxide semiconductor layer;

a first insulating layer over the source electrode and the drain electrode, the first insulating layer being in contact with part of the oxide semiconductor layer; and

a second insulating layer over the first insulating layer,

wherein an amount of oxygen in the first insulating layer is greater than an amount of oxygen in a stoichiometric composition, and

wherein the second insulating layer is thicker than the first insulating layer.

13. The semiconductor device according to claim 12, wherein the thickness of the first insulating layer is more than 10 nm and less than 100 nm.

14. The semiconductor device according to claim 12, wherein the thickness of the second insulating layer is more than 200 nm and less than 500 nm.

15. The semiconductor device according to claim 12, wherein the oxide semiconductor layer comprises crystals whose c-axis is aligned in a direction perpendicular to a surface of the oxide semiconductor layer.

16. The semiconductor device according to claim 12, wherein the oxide semiconductor layer comprises at least one material selected from the group consisting of indium and zinc.

17. The semiconductor device according to claim 16, wherein the oxide semiconductor layer further comprises at least one material selected from the group consisting of gallium, tin, hafnium, aluminum, and zirconium.

18. The semiconductor device according to claim 12, further comprising a third insulating layer comprising a metal oxide over the second insulating layer.

19. The semiconductor device according to claim 18, wherein the metal oxide is aluminum oxide.