Semiconductor device wherein each of a first oxide semiconductor layer and a second oxide semiconductor layer includes a portion that is in an oxygen-excess state and is in contact with an insulating layer

• US 8,885,115 B2
• Filed: 01/27/2014
• Issued: 11/11/2014
• Est. Priority Date: 08/07/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Sakata, Junichiro, Sakakura, Masayuki, Oikawa, Yoshiaki, Okazaki, Kenichi, Maruyama, Hotaka, Tsubuku, Masashi
• Primary Examiner(s): Lee, Paul
• Application Number:
  US14/164,713
• Publication Number:
  US 20140138681A1
• Time in Patent Office: 288 Days
• Field of Search: 349/42, 349/43, 349/140
• US Class Current: 349/43
• CPC Class Codes: G02F 1/13306 Circuit arrangements or driving methods for the control of single liquid crystal cells G02F1/132, G02F1/133382 take precedence
• CPC Class Codes: G02F 1/133302 Rigid substrates, e.g. inorganic substrates
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/133357 Planarisation layers
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/1337 Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
• CPC Class Codes: G02F 1/1339 Gaskets; Spacers; Sealing of cells
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence
• CPC Class Codes: G02F 1/134336 Matrix
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/136204 Arrangements to prevent high voltage or static electricity failures
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2201/123 pixel
• CPC Class Codes: G11C 19/28 using semiconductor elements G11C19/14, G11C19/36 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 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 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 27/127 with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/1288 : employing particular masking sequences or specially adapted masks, e.g. half-tone mask
• CPC Class Codes: H01L 29/247 : Amorphous materials
• 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 29/78648 : arranged on opposing sides of the channel
• 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 improve reliability of a semiconductor device. A semiconductor device including a driver circuit portion and a display portion (also referred to as a pixel portion) over the same substrate is provided. The driver circuit portion and the display portion include thin film transistors in which a semiconductor layer includes an oxide semiconductor; a first wiring; and a second wiring. The thin film transistors each include a source electrode layer and a drain electrode layer. In the thin film transistor in the driver circuit portion, the semiconductor layer is sandwiched between a gate electrode layer and a conductive layer. The first wiring and the second wiring are electrically connected to each other in an opening provided in a gate insulating film through an oxide conductive layer.

Claims

1. A semiconductor device comprising:

a driver circuit portion comprising a first transistor, the first transistor comprising a first oxide semiconductor layer and a conductive layer over the first oxide semiconductor layer; and

a pixel portion comprising a second transistor, the second transistor comprising a second oxide semiconductor layer,

wherein an insulating layer is over the first oxide semiconductor layer and the second oxide semiconductor layer,

wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer comprises a portion in contact with the insulating layer,

wherein the portion is in an oxygen-excess state, and

wherein the conductive layer overlaps the portion.

2. The semiconductor device according to claim 1,

wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer further comprises a source region and a drain region, and

wherein the portion is between the source region and the drain region.

3. The semiconductor device according to claim 2, wherein a carrier concentration of the portion is lower than a carrier concentration of the source region and the drain region.

4. The semiconductor device according to claim 2,

wherein each of the first transistor and the second transistor further comprises a source electrode layer and a drain electrode layer, and

wherein the source electrode layer is electrically connected to the source region, and

wherein the drain electrode layer is electrically connected to the drain region.

5. The semiconductor device according to claim 1,

wherein each of the first transistor and the second transistor further comprises a gate electrode layer, and

wherein the gate electrode layer and the portion overlap each other.

6. The semiconductor device according to claim 1, wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer contains indium, gallium, and zinc.

7. The semiconductor device according to claim 1, wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer contains indium, tin, and zinc.

8. The semiconductor device according to claim 1, wherein the first oxide semiconductor layer is the same material as the second oxide semiconductor layer.

9. An electronic appliance comprising the semiconductor device according to claim 1, wherein the electronic appliance is one selected from the group consisting of a television set, a monitor of computer, a camera, a digital photo frame, a cellular phone, a portable gate console, a portable information terminal, an audio reproducing device, and a large-sized game machine.

10. An electronic appliance comprising the semiconductor device according to claim 1, wherein the electronic appliance is a watch.

11. A semiconductor device comprising:

a driver circuit portion comprising a first transistor, the first transistor comprising a first oxide semiconductor layer and a conductive layer over the first oxide semiconductor layer; and

a pixel portion comprising a second transistor, the second transistor comprising a second oxide semiconductor layer,

wherein an insulating layer is over the first oxide semiconductor layer and the second oxide semiconductor layer,

wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer comprises a source region, a drain region, and a portion between the source region and the drain region,

wherein the portion is in contact with the insulating layer,

wherein the portion is in an oxygen-excess state, and

wherein the conductive layer overlaps the portion.

12. The semiconductor device according to claim 11, wherein a carrier concentration of the portion is lower than a carrier concentration of the source region and the drain region.

13. The semiconductor device according to claim 11,

wherein each of the first transistor and the second transistor further comprises a source electrode layer and a drain electrode layer, and

wherein the source electrode layer is electrically connected to the source region, and

wherein the drain electrode layer is electrically connected to the drain region.

14. The semiconductor device according to claim 11,

wherein each of the first transistor and the second transistor further comprises a gate electrode layer, and

wherein the gate electrode layer and the portion overlap each other.

15. The semiconductor device according to claim 11, wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer contains indium, gallium, and zinc.

16. The semiconductor device according to claim 11, wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer contains indium, tin, and zinc.

17. The semiconductor device according to claim 11, wherein the first oxide semiconductor layer is the same material as the second oxide semiconductor layer.

18. An electronic appliance comprising the semiconductor device according to claim 11, wherein the electronic appliance is one selected from the group consisting of a television set, a monitor of computer, a camera, a digital photo frame, a cellular phone, a portable gate console, a portable information terminal, an audio reproducing device, and a large-sized game machine.

19. An electronic appliance comprising the semiconductor device according to claim 11, wherein the electronic appliance is a watch.