SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME

• US 20130161610A1
• Filed: 12/20/2012
• Published: 06/27/2013
• Est. Priority Date: 12/27/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: YAMAZAKI, Shunpei
• Granted Patent: US 9,502,572 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02244 of a metallic layer
• CPC Class Codes: H01L 21/02614 Transformation of metal, e.g. oxidation, nitridation
• 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 27/14612 involving a transistor
• CPC Class Codes: H01L 27/14692 Thin film technologies, e.g. amorphous, poly, micro- or nanocrystalline silicon
• 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 29/7869 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 59/12 Active-matrix OLED [AMOLED] displays

Abstract

A highly reliable semiconductor device which includes a transistor including an oxide semiconductor is provided. In a semiconductor device including a bottom-gate transistor including an oxide semiconductor layer, a stacked layer of an insulating layer and a metal film is provided in contact with the oxide semiconductor layer. Oxygen doping treatment is performed in a manner such that oxygen is introduced into the insulating layer and the metal film from a position above the metal film. Thus, a region containing oxygen in excess of the stoichiometric composition is formed in the insulating layer, and the metal film is oxidized to form a metal oxide film. Further, resistivity of the metal oxide film is greater than or equal to 1×10¹⁰ Ωm and less than or equal to 1×10¹⁹ Ωm.

Claims

1. A semiconductor device comprising:

a gate electrode layer;

a gate insulating layer over the gate electrode layer;

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

a source electrode layer over the oxide semiconductor layer, the source electrode layer being electrically connected to the oxide semiconductor layer;

a drain electrode layer over the oxide semiconductor layer, the drain electrode layer being electrically connected to the oxide semiconductor layer;

an insulating layer over and in contact with the oxide semiconductor layer; and

a metal oxide film over and in contact with the insulating layer,

wherein the metal oxide film has a resistivity greater than or equal to 1×

10¹⁰ Ω

m and less than or equal to 1×

10¹⁹ Ω

m.

2. The semiconductor device according to claim 1,

wherein the insulating layer is formed over the source electrode layer and the drain electrode layer, and

wherein the insulating layer between the source electrode layer and the drain electrode layer is in contact with the oxide semiconductor layer.

3. The semiconductor device according to claim 1,

wherein the source electrode layer is formed over the insulating layer,

wherein the drain electrode layer is formed over the insulating layer,

wherein the insulating layer has a first opening and a second opening,

wherein the source electrode layer is in contact with the oxide semiconductor layer through the first opening, and

wherein the drain electrode layer is in contact with the oxide semiconductor layer through the second opening.

4. The semiconductor device according to claim 1, wherein the insulating layer comprises a region containing oxygen in excess of a stoichiometric composition.

5. The semiconductor device according to claim 1, wherein the metal oxide film is an aluminum oxide film.

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

forming a gate electrode layer;

forming a gate insulating layer over the gate electrode layer;

forming an oxide semiconductor layer to overlap with the gate electrode layer with the gate insulating layer interposed therebetween;

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

forming an insulating layer over the source electrode layer and the drain electrode layer;

forming a metal film over the insulating layer; and

adding oxygen to the metal film and the insulating layer so that a metal oxide film having a resistivity greater than or equal to 1×

10¹⁰ Ω

m and less than or equal to 1×

10¹⁹ Ω

m is formed over the insulating layer.

7. The method for manufacturing a semiconductor device according to claim 6, further comprising the step of performing a heat treatment on the insulating layer before forming the metal film so that water or hydrogen in the insulating layer is reduced.

8. The method for manufacturing a semiconductor device according to claim 6,

wherein the metal film is an aluminum film, and

wherein the metal oxide film is an aluminum oxide film.

9. The method for manufacturing a semiconductor device according to claim 6, further comprising the step of performing a heat treatment on the insulating layer after adding oxygen to the metal film and the insulating layer so that oxygen is supplied from the insulating layer to the oxide semiconductor layer.

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

forming a gate electrode layer;

forming a gate insulating layer over the gate electrode layer;

forming an oxide semiconductor layer to overlap with the gate electrode layer with the gate insulating layer interposed therebetween;

forming an insulating layer over and in contact with the oxide semiconductor layer;

forming a metal film over the insulating layer;

adding oxygen to the metal film and the insulating layer so that a metal oxide film having a resistivity greater than or equal to 1×

10¹⁰ Ω

m and less than or equal to 1×

10¹⁹ Ω

m is formed over the insulating layer;

forming a first opening and a second opening in the insulating layer; and

forming a source electrode layer in contact with the oxide semiconductor layer through the first opening and a drain electrode layer in contact with the oxide semiconductor layer through the second opening.

11. The method for manufacturing a semiconductor device according to claim 10, further comprising the step of performing a heat treatment on the insulating layer before forming the metal film so that water or hydrogen in the insulating layer is reduced.

12. The method for manufacturing a semiconductor device according to claim 10,

wherein the metal film is an aluminum film, and

wherein the metal oxide film is an aluminum oxide film.

13. The method for manufacturing a semiconductor device according to claim 10, further comprising the step of performing a heat treatment on the insulating layer after adding oxygen to the metal film and the insulating layer so that oxygen is supplied from the insulating layer to the oxide semiconductor layer.