Semiconductor device and method for manufacturing the same

• US 9,054,138 B2
• Filed: 09/15/2014
• Issued: 06/09/2015
• Est. Priority Date: 07/10/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Sakakura, Masayuki
• Primary Examiner(s): Le, Thao P
• Application Number:
  US14/486,187
• Publication Number:
  US 20150004745A1
• Time in Patent Office: 267 Days
• Field of Search: 438/116
• US Class Current: 1/1
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• 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 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/1248 with a particular composition or shape of the interlayer dielectric specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• 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 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/42 Transparent materials

Abstract

It is an object to manufacture and provide a highly reliable display device including a thin film transistor with a high aperture ratio which has stable electric characteristics. In a manufacturing method of a semiconductor device having a thin film transistor in which a semiconductor layer including a channel formation region is formed using an oxide semiconductor film, a heat treatment for reducing moisture and the like which are impurities and for improving the purity of the oxide semiconductor film (a heat treatment for dehydration or dehydrogenation) is performed. Further, an aperture ratio is improved by forming a gate electrode layer, a source electrode layer, and a drain electrode layer using conductive films having light transmitting properties.

Claims

1. A method of manufacturing a display panel comprising:

forming a first conductive film over a substrate;

selectively etching the first conductive film to form a gate electrode of a transistor in a pixel portion and a first conductive layer in a terminal portion;

forming a first insulating film over the gate electrode and the first conductive layer;

forming a first transparent conductive film over the first insulating film;

selectively etching the first transparent conductive film to form a first transparent conductive layer in the terminal portion, the first transparent conductive layer overlapping with the first conductive layer;

forming a second insulating film over the first transparent conductive layer;

forming a second transparent conductive film over the second insulating film;

selectively etching the second transparent conductive film to form a pixel electrode in the pixel portion and a second transparent conductive layer in the terminal portion,

wherein the pixel electrode is electrically connected to the transistor,

wherein the second transparent conductive layer is in contact with the first transparent conductive layer through an opening of the second insulating film, and

wherein the second transparent conductive layer is electrically connected to the first conductive layer through an opening of the first insulating film.

2. The method according to claim 1, wherein the first conductive film has a light transmitting property.

3. The method according to claim 1, wherein the transistor is a bottom gate thin film transistor.

4. The method according to claim 1, further comprising a step of forming a semiconductor layer over the first insulating film.

5. The method according to claim 1, further comprising a step of forming an oxide semiconductor layer over the first insulating film.

6. The method according to claim 1, wherein the second transparent conductive layer is in direct contact with the first conductive layer.

7. A method of manufacturing a display panel comprising:

forming a first conductive film over a substrate;

selectively etching the first conductive film to form a gate electrode of a transistor in a pixel portion and a first conductive layer in a terminal portion;

forming a first insulating film over the gate electrode and the first conductive layer;

forming a first transparent conductive film over the first insulating film;

selectively etching the first transparent conductive film to form a first transparent conductive layer in the terminal portion and a capacitor electrode in the pixel portion, the first transparent conductive layer overlapping with the first conductive layer;

forming a second insulating film over the first transparent conductive layer;

forming a second transparent conductive film over the second insulating film;

selectively etching the second transparent conductive film to form a pixel electrode in the pixel portion and a second transparent conductive layer in the terminal portion,

wherein the pixel electrode is electrically connected to the transistor,

wherein the second transparent conductive layer is in contact with the first transparent conductive layer through an opening of the second insulating film, and

wherein the second transparent conductive layer is electrically connected to the first conductive layer through an opening of the first insulating film.

8. The method according to claim 7, wherein the first conductive film has a light transmitting property.

9. The method according to claim 7, wherein the transistor is a bottom gate thin film transistor.

10. The method according to claim 7, further comprising a step of forming a semiconductor layer over the first insulating film.

11. The method according to claim 7, further comprising a step of forming an oxide semiconductor layer over the first insulating film.

12. The method according to claim 7, wherein the second transparent conductive layer is in direct contact with the first conductive layer.