Semiconductor device and method for manufacturing semiconductor device

• US 8,987,048 B2
• Filed: 03/31/2014
• Issued: 03/24/2015
• Est. Priority Date: 07/18/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Sakata, Junichiro, Miyake, Hiroyuki, Kuwabara, Hideaki
• Primary Examiner(s): ULLAH, ELIAS
• Application Number:
  US14/230,731
• Publication Number:
  US 20140209902A1
• Time in Patent Office: 358 Days
• Field of Search: 257/59, 257/71, 257/43, 257/E21.704, 257/E29.296, 257/E27.111, 438/158, 438/104
• US Class Current: 438/104
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• 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 27/1262 with a particular formation, treatment or coating of the substrate
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• CPC Class Codes: H01L 29/78606 with supplementary region or layer in the thin film or in the insulated bulk substrate supporting it for controlling or increasing the safety of the device H01L29/78642, H01L29/78645 take precedence
• 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

An object is to reduce the manufacturing cost of a semiconductor device. An object is to improve the aperture ratio of a semiconductor device. An object is to make a display portion of a semiconductor device display a higher-definition image. An object is to provide a semiconductor device which can be operated at high speed. The semiconductor device includes a driver circuit portion and a display portion over one substrate. The driver circuit portion includes: a driver circuit TFT in which source and drain electrodes are formed using a metal and a channel layer is formed using an oxide semiconductor; and a driver circuit wiring formed using a metal. The display portion includes: a pixel TFT in which source and drain electrodes are formed using an oxide conductor and a semiconductor layer is formed using an oxide semiconductor; and a display wiring formed using an oxide conductor.

Claims

1. A method for manufacturing a semiconductor device comprising a pixel portion and a driver circuit portion, comprising:

forming a first conductive layer in the pixel portion and the driver portion;

forming a first insulating layer over the first conductive layer in the pixel portion and the driver portion;

forming an oxide semiconductor layer over the first insulating layer in the pixel portion and the driver portion;

forming a second insulating layer over and in contact with a part of the oxide semiconductor layer in the pixel portion and the driver portion;

forming a second conductive layer and a third conductive layer over the second insulating layer and the oxide semiconductor layer in the pixel portion and the driver portion;

forming a fourth conductive layer electrically connected to one of the second conductive layer and the third conductive layer in the pixel portion; and

forming a fifth conductive layer overlapping the first conductive layer in the driver circuit portion,

wherein the fourth conductive layer and the fifth conductive layer are formed on a same surface.

2. The method for manufacturing a semiconductor device according to claim 1, wherein the first conductive layer comprises copper.

3. The method for manufacturing a semiconductor device according to claim 1, wherein the oxide semiconductor layer comprises indium, gallium, and zinc.

4. The method for manufacturing a semiconductor device according to claim 1, wherein each of the fourth conductive layer and the fifth conductive layer comprises zinc.

5. The method for manufacturing a semiconductor device according to claim 1, wherein each of the fourth conductive layer and the fifth conductive layer has a light-transmitting property.

6. The method for manufacturing a semiconductor device according to claim 1,

wherein the fourth conductive layer is formed over the second insulating layer in the pixel portion, and

wherein the fifth conductive layer is formed over the second insulating layer in the driver circuit portion.

7. The method for manufacturing a semiconductor device according to claim 1, wherein the second insulating layer comprises silicon oxynitride.

8. The method for manufacturing a semiconductor device according to claim 1, wherein the first conductive layer of the driver circuit portion and the fifth conductive layer are supplied with a same potential.

9. The method for manufacturing a semiconductor device according to claim 1, wherein the pixel portion further comprises a capacitor having a light-transmitting property.

10. The method for manufacturing a semiconductor device according to claim 1,

wherein the oxide semiconductor layer comprises a region in contact with the second insulating layer, and

wherein a carrier concentration of the region is less than 1×

10¹⁷/cm³.

11. A method for manufacturing a semiconductor device comprising a pixel portion and a driver circuit portion, comprising:

forming a first conductive layer in the pixel portion and the driver circuit portion;

forming a first insulating layer over the first conductive layer in the pixel portion and the driver circuit portion;

forming an oxide semiconductor layer over the first insulating layer in the pixel portion and the driver circuit portion;

forming a second insulating layer over and in contact with a part of the oxide semiconductor layer in the pixel portion and the driver circuit portion;

forming a second conductive layer and a third conductive layer over the second insulating layer and the oxide semiconductor layer in the pixel portion and the driver circuit portion;

forming a third insulating layer over the second conductive layer and the third conductive layer in the pixel portion and the driver circuit portion;

forming a fourth conductive layer electrically connected to one of the second conductive layer and the third conductive layer in the pixel portion; and

forming a fifth conductive layer overlapping the first conductive layer in the driver circuit portion,

wherein the fourth conductive layer and the fifth conductive layer are formed on a same surface.

12. The semiconductor device according to claim 11, wherein the first conductive layer comprises copper.

13. The semiconductor device according to claim 11, wherein the oxide semiconductor layer comprises indium, gallium, and zinc.

14. The semiconductor device according to claim 11, wherein each of the fourth conductive layer and the fifth conductive layer comprises zinc.

15. The method for manufacturing a semiconductor device according to claim 11, wherein each of the fourth conductive layer and the fifth conductive layer has a light-transmitting property.

16. The method for manufacturing a semiconductor device according to claim 11,

wherein the fourth conductive layer is formed over the second insulating layer in the pixel portion, and

wherein the fifth conductive layer is formed over the second insulating layer in the driver circuit portion.

17. The semiconductor device according to claim 11, wherein the second insulating layer comprises silicon oxynitride.

18. The semiconductor device according to claim 11, wherein the third insulating layer comprises silicon nitride.

19. The semiconductor device according to claim 11, wherein the first conductive layer of the driver circuit portion and the fifth conductive layer are supplied with a same potential.

20. The semiconductor device according to claim 11, wherein the pixel portion further comprises a capacitor having a light-transmitting property.

21. The semiconductor device according to claim 11,

wherein the oxide semiconductor layer comprises a region in contact with the second insulating layer, and

wherein a carrier concentration of the region is less than 1×

10¹⁷/cm³.