SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF

• US 20110084263A1
• Filed: 09/30/2010
• Published: 04/14/2011
• Est. Priority Date: 10/09/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: ITO, Yoshiaki, YAMAZAKI, Shunpei, TAKAHASHI, Kei
• Granted Patent: US 9,006,728 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 27/1251 comprising TFTs having a different architecture, e.g. top- and bottom gate TFTs
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• CPC Class Codes: H01L 29/0611 for increasing or controlling the breakdown voltage of reverse biased devices H01L29/0661 takes precedence
• 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 29/41733 for thin film transistors with insulated gate
• CPC Class Codes: H01L 29/42384 for thin film field effect transistors, e.g. characterised by the thickness or the shape of the insulator or the dimensions, the shape or the lay-out of the conductor
• CPC Class Codes: H01L 29/66477 with an insulated gate, i.e. MISFET
• 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 29/78618 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 29/78642 Vertical transistors
• CPC Class Codes: H01L 29/78648 arranged on opposing sides of the channel
• 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: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

It is an object to provide a semiconductor device having a new productive semiconductor material and a new structure. The semiconductor device includes a first conductive layer over a substrate, a first insulating layer which covers the first conductive layer, an oxide semiconductor layer over the first insulating layer that overlaps with part of the first conductive layer and has a crystal region in a surface part, second and third conductive layers formed in contact with the oxide semiconductor layer, an insulating layer which covers the oxide semiconductor layer and the second and third conductive layers, and a fourth conductive layer over the insulating layer that overlaps with part of the oxide semiconductor layer.

Claims

1. A semiconductor device comprising:

a first conductive layer over a substrate;

a first insulating layer over the first conductive layer;

an oxide semiconductor layer over the first insulating layer and overlaps with the first conductive layer;

a second conductive layer and a third conductive layer formed in contact with the oxide semiconductor layer;

a second insulating layer over the oxide semiconductor layer, the second conductive layer and the third conductive layer;

a fourth conductive layer over the second insulating layer and overlaps with a part of the oxide semiconductor layer; and

wherein an upper surface of the oxide semiconductor layer has a crystal region.

2. The semiconductor device according to claim 1, wherein a region except the crystal region in the oxide semiconductor layer is amorphous.

3. The semiconductor device according to claim 1, wherein the crystal region in the oxide semiconductor layer contains a crystal of In₂Ga₂ZnO₇.

4. The semiconductor device according to any one of claims 1, wherein one of the second conductive layer and the third conductive layer is electrically connected to the oxide semiconductor layer on an upper surface or a lower surface of the oxide semiconductor layer.

5. The semiconductor device according to any one of claims 1, wherein the oxide semiconductor layer contains an In—

Ga—

Zn—

O-based oxide semiconductor material.

6. The semiconductor device according to any one of claims 1, wherein the second conductive layer, the third conductive layer, and the fourth conductive layer function as one of a source electrode and a drain electrode, the other of the source electrode and the drain electrode, and a gate electrode, respectively.

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

forming a first conductive layer over a substrate;

forming a first insulating layer covering the first conductive layer;

forming an oxide semiconductor layer which overlaps with the first conductive layer over the first insulating layer;

forming a crystal region in an upper surface of the oxide semiconductor layer by heat treatment of the oxide semiconductor layer;

forming a second conductive layer and a third conductive layer which are in contact with the oxide semiconductor layer;

forming an second insulating layer over the oxide semiconductor layer and the second and third conductive layers; and

forming a fourth conductive layer which overlaps with a part of the oxide semiconductor layer over the second insulating layer.

8. The method for manufacturing a semiconductor device, according to claim 7, wherein the crystal region is formed by heat treatment so that the temperature of the oxide semiconductor layer is 500°

C. or higher.

9. The method for manufacturing a semiconductor device, according to claim 7, wherein the oxide semiconductor layer is formed by sputtering with the use of an In—

Ga—

Zn—

O-based target.

10. A semiconductor device comprising:

a first conductive layer over a substrate;

a first insulating layer over the first conductive layer;

an oxide semiconductor layer over the first insulating layer and overlaps with the first conductive layer;

a second conductive layer and a third conductive layer formed in contact with the oxide semiconductor layer;

a second insulating layer over the oxide semiconductor layer, the second conductive layer and the third conductive layer;

a fourth conductive layer over the second insulating layer and overlaps with a part of the oxide semiconductor layer

wherein the oxide semiconductor layer includes a first region and a second region where the first region is closer to the first insulating layer than the second region and the second region is in contact with the second insulating layer, and

wherein the second region has a crystallinity and the first region has an amorphous structure.

11. The semiconductor device according to claim 10, wherein the second region in the oxide semiconductor layer contains a crystal of In₂Ga₂ZnO₇.

12. The semiconductor device according to any one of claims 10, wherein one of the second conductive layer and the third conductive layer is electrically connected to the oxide semiconductor layer on an upper surface or a lower surface of the oxide semiconductor layer.

13. The semiconductor device according to any one of claims 10, wherein the oxide semiconductor layer contains an In—

Ga—

Zn—

O-based oxide semiconductor material.

14. The semiconductor device according to any one of claims 10, wherein the second conductive layer, the third conductive layer, and the fourth conductive layer function as one of a source electrode and a drain electrode, the other of the source electrode and the drain electrode, and a gate electrode, respectively.