METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

• US 20110008931A1
• Filed: 07/08/2010
• Published: 01/13/2011
• Est. Priority Date: 07/10/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: HOSOBA, Miyuki, SASAKI, Toshinari, NODA, Kosei, OHARA, Hiroki, YAMAZAKI, Shunpei, SAKATA, Junichiro
• Granted Patent: US 8,900,916 B2
• Time in Patent Office: Days
• US Class Current: 438/104
• CPC Class Codes: H01L 21/477 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/38 - H01L21/449 and H01L21/461 - H01L21/475 take precedence
• 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 29/66969 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

Abstract

A highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics, and a manufacturing method thereof. In the manufacturing method of the semiconductor device which includes a thin film transistor where a semiconductor layer including a channel formation region is an oxide semiconductor layer, heat treatment which reduces impurities such as moisture to improve the purity of the oxide semiconductor layer and oxidize the oxide semiconductor layer (heat treatment for dehydration or dehydrogenation) is performed. Not only impurities such as moisture in the oxide semiconductor layer but also those existing in a gate insulating layer are reduced, and impurities such as moisture existing in interfaces between the oxide semiconductor layer and films provided over and under and in contact with the oxide semiconductor layer are reduced.

Claims

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

forming a gate electrode layer over a substrate having an insulating surface;

forming a gate insulating layer over the gate electrode layer;

forming an oxide semiconductor layer over the gate insulating layer;

heating the oxide semiconductor layer in an oxygen atmosphere;

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

forming an oxide insulating layer which is in contact with part of the oxide semiconductor layer, over the gate insulating layer, the oxide semiconductor layer, and the source and drain electrode layers; and

performing a heat treatment in an oxygen atmosphere or an inert gas atmosphere.

5. The method for manufacturing a semiconductor device according to any one of claims 1 to 4, wherein a temperature at which the oxide semiconductor layer is heated in the oxygen atmosphere is higher than or equal to 200°

C. and lower than a strain point of the substrate.

6. The method for manufacturing a semiconductor device according to any one of claims 1 to 4, wherein after the oxide semiconductor layer is heated in the oxygen atmosphere, the oxide semiconductor layer is held in the oxygen atmosphere.

7. The method for manufacturing a semiconductor device according to any one of claims 1 to 4, wherein after the oxide semiconductor layer is heated in the oxygen atmosphere, the oxide semiconductor layer is held in an inert gas atmosphere.

2. A method for manufacturing a semiconductor device, comprising:

forming a gate electrode layer over a substrate having an insulating surface;

forming a gate insulating layer over the gate electrode layer;

forming an oxide semiconductor layer over the gate insulating layer;

heating the oxide semiconductor layer in an oxygen atmosphere, so that the oxide semiconductor layer is dehydrated or dehydrogenated;

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

forming an oxide insulating layer which is in contact with part of the oxide semiconductor layer, over the gate insulating layer, the oxide semiconductor layer, and the source and drain electrode layers; and

performing a heat treatment in an oxygen atmosphere or an inert gas atmosphere.

3. A method for manufacturing a semiconductor device, comprising:

forming an oxide semiconductor layer over an insulating layer;

heating the oxide semiconductor layer in an oxygen atmosphere;

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

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

performing a heat treatment in an oxygen atmosphere or an inert gas atmosphere.

4. A method for manufacturing a semiconductor device, comprising:

forming an oxide semiconductor layer over an insulating layer;

heating the oxide semiconductor layer in an oxygen atmosphere, so that the oxide semiconductor layer is dehydrated or dehydrogenated;

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

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

performing a heat treatment in an oxygen atmosphere or an inert gas atmosphere.