SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME

• US 20110053322A1
• Filed: 06/29/2010
• Published: 03/03/2011
• Est. Priority Date: 06/30/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: YAMAZAKI, Shunpei, SASAKI, Toshinari, SAKATA, Junichiro, OHARA, Hiroki
• Granted Patent: US 8,557,641 B2
• Time in Patent Office: Days
• US Class Current: 438/149
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02664 Aftertreatments planarisation in general H01L21/304
• 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 29/66765 Lateral single gate single channel transistors with inverted structure, i.e. the channel layer is formed after the gate
• 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 29/7869 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

An object is to provide a high reliable semiconductor device including a thin film transistor having stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (which is for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor film and reduce impurities such as moisture. Besides impurities such as moisture existing in the oxide semiconductor film, heat treatment causes reduction of impurities such as moisture existing in the gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor film and are in contact with the oxide semiconductor film.

Claims

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

forming an oxide semiconductor layer over an insulating layer;

performing dehydration or dehydrogenation on the oxide semiconductor layer;

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

forming an oxide insulating film which is in contact with a part of the oxide semiconductor layer and is over the insulating layer, the oxide semiconductor layer, the source electrode layer, and the drain electrode layer.

2. The manufacturing method of a semiconductor device according to claim 1, wherein the dehydration or dehydrogenation is a heat treatment performed under a nitrogen atmosphere or a rare gas atmosphere or under a reduced pressure.

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

forming an oxide semiconductor layer over an insulating layer;

heating the oxide semiconductor layer under an inert atmosphere to increase a carrier concentration;

forming a source electrode layer and a drain electrode layer over the oxide semiconductor layer whose carrier concentration is increased; and

forming an oxide insulating film which is in contact with a part of the heated oxide semiconductor layer and is over the insulating layer, the heated oxide semiconductor layer, the source electrode layer, and the drain electrode layer, so that a carrier concentration is reduced.

4. The method for manufacturing a semiconductor device according to claim 3, wherein the inert atmosphere is a nitrogen atmosphere or a rare gas atmosphere.

5. The method for manufacturing a semiconductor device according to claim 3, wherein the oxide semiconductor layer is heated under an inert atmosphere at a temperature equal to or higher than 400°

C.

6. The method for manufacturing a semiconductor device according to claim 3, wherein the oxide semiconductor layer is heated under an inert atmosphere at a temperature equal to higher than 400°

C., and then, slow cooling is performed to a temperature equal to or higher than room temperature and lower than 100°

C.

7. The method for manufacturing a semiconductor device according to claim 3, wherein a carrier concentration of the oxide semiconductor layer whose carrier concentration is increased is 1×

10¹⁸/cm³ or higher.

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

forming an oxide semiconductor layer over an insulating layer;

heating the oxide semiconductor layer under a reduced pressure to increase a carrier concentration;

forming a source electrode layer and a drain electrode layer over the oxide semiconductor layer whose carrier concentration is increased, and

forming an oxide insulating film which is contact with a part of the heated oxide semiconductor layer and is over the insulating layer, the heated oxide semiconductor layer, the source electrode layer, and the drain electrode layer, so that a carrier concentration is reduced.

9. The method for manufacturing a semiconductor device according to claim 8, wherein a carrier concentration of the oxide semiconductor layer whose carrier concentration is increased is 1×

10¹⁸/cm³ or higher.

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

forming an oxide semiconductor layer over an insulating layer;

heating the oxide semiconductor layer so as to at least partly dehydrate or dehydrogenate the oxide semiconductor layer to remove hydrogen in the oxide semiconductor layer;

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

forming an oxide insulating film which is in contact with a part of the heated oxide semiconductor layer and is over the insulating layer, the heated oxide semiconductor layer, the source electrode layer, and the drain electrode layer.