Semiconductor device and manufacturing method of the same

• US 9,041,202 B2
• Filed: 05/04/2009
• Issued: 05/26/2015
• Est. Priority Date: 05/16/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kimura, Hajime
• Primary Examiner(s): WOLDEGEORGIS, ERMIAS T
• Application Number:
  US12/434,948
• Publication Number:
  US 20090283762A1
• Time in Patent Office: 2,213 Days
• Field of Search: 257 49- 52, 257/59, 257/66, 257/72, 257/E27.111, 257/E29.147, 257/E29.151, 257/E29.295, 257/748
• US Class Current: 257/748
• 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 27/1288 employing particular masking sequences or specially adapted masks, e.g. half-tone mask
• CPC Class Codes: H01L 28/40 Capacitors
• CPC Class Codes: H01L 29/4966 the conductor material next to the insulator being a composite material, e.g. organic material, TiN, MoSi2 H01L29/4908, H01L29/4983 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
• 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 33/02 characterised by the semiconductor bodies
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/1216 the pixel elements being capacitors

Abstract

An object is to provide a semiconductor device with high aperture ratio or a manufacturing method thereof. Another object is to provide semiconductor device with low power consumption or a manufacturing method thereof. A light-transmitting conductive layer which functions as a gate electrode, a gate insulating film formed over the light-transmitting conductive layer, a semiconductor layer formed over the light-transmitting conductive layer which functions as the gate electrode with the gate insulating film interposed therebetween, and a light-transmitting conductive layer which is electrically connected to the semiconductor layer and functions as source and drain electrodes are included.

Claims

1. A semiconductor device comprising:

a first conductive film;

a second conductive film over the first conductive film;

a first insulating film over the first conductive film and the second conductive film;

a semiconductor film provided over the first insulating film;

a third conductive film over the semiconductor film;

a fourth conductive film over the third conductive film;

a second insulating film covering the semiconductor film, the third conductive film and the fourth conductive film;

a pixel electrode provided over the second insulating film and electrically connected to the semiconductor film;

a transistor using a first portion of the first conductive film as a gate electrode, a first portion of the third conductive film as a source electrode and a first portion of the first insulating film as a gate dielectric; and

a storage capacitor using a second portion of the third conductive film as an upper electrode, a second portion of the first conductive film as a lower electrode, and a second portion of the first insulating film as a dielectric,

wherein an entirety of the second conductive film overlaps with the first conductive film while the first portion of the first conductive film and the second portion of the first conductive film do not overlap with the second conductive film,

wherein an entirety of the fourth conductive film overlaps with the third conductive film while the first portion of the third conductive film and the second portion of the third conductive film do not overlap with the fourth conductive film,

wherein the semiconductor film does not overlap with the second conductive film, and

wherein the storage capacitor is transparent such that a light passes through the storage capacitor from one of the first insulating film and the second insulating film to the other of the first insulating film and the second insulating film.

2. The semiconductor device according to claim 1, wherein the first conductive film and the third conductive film have a light-transmitting property.

3. The semiconductor device according to claim 1, wherein the second conductive film and the fourth conductive film have a light-shielding property.

4. The semiconductor device according to claim 1, wherein the second conductive film and the fourth conductive film have higher conductivity than the first conductive film and the third conductive film.

5. The semiconductor device according to claim 1, wherein the second conductive film is formed of one or a plurality of elements selected from Al, Ti, Cu. Au, Ag, Mo, Ni, Ta, Zr, and Co.

6. The semiconductor device according to claim 1, wherein the fourth conductive film is formed of one or a plurality of elements selected from Al, Ti, Cu, Au, Ag, Mo, Ni, Ta, Zr, and Co.

7. The semiconductor device according to claim 1, wherein the semiconductor film is any one of materials selected from zinc oxide, titanium oxide, magnesium zinc oxide, cadmium zinc oxide, cadmium oxide, InGaO₃(ZnO)₅, and a-IGZO.

8. The semiconductor device according to claim 1,

wherein the fourth conductive film does not overlap with the semiconductor film.

9. A semiconductor device comprising:

a first conductive film;

a second conductive film over the first conductive film;

a first insulating film over the first conductive film and the second conductive film;

a semiconductor film provided over the first insulating film;

a third conductive film over the semiconductor film;

a fourth conductive film over the third conductive film;

a second insulating film covering the semiconductor film, the third conductive film and the fourth conductive film;

a pixel electrode provided over the second insulating film and electrically connected to the semiconductor film;

a transistor using a first portion of the first conductive film as a gate electrode, a first portion of the third conductive film as a source electrode and a first portion of the first insulating film as a gate dielectric;

a capacitor wiring; and

a storage capacitor using a second portion of the third conductive film as an upper electrode, a second portion of the first conductive film as a lower electrode, and a second portion of the first insulating film as a dielectric,

wherein an entirety of the second conductive film overlaps with the first conductive film while the first portion of the first conductive film and the second portion of the first conductive film do not overlap with the second conductive film,

wherein an entirety of the fourth conductive film overlaps with the third conductive film while the first portion of the third conductive film and the second portion of the third conductive film do not overlap with the fourth conductive film,

wherein the semiconductor film does not overlap with the second conductive film,

wherein the storage capacitor is transparent such that a light passes through the storage capacitor from one of first insulating film and the second insulating film to the other of the first insulating film and the second insulating film, and

wherein the capacitor wiring comprises a same material as the semiconductor film.

10. The semiconductor device according to claim 9, wherein the first conductive film and the third conductive film have a light-transmitting property.

11. The semiconductor device according to claim 9, wherein the second conductive film and the fourth conductive film have a light-shielding property.

12. The semiconductor device according to claim 9, wherein the second conductive film and the fourth conductive film have higher conductivity than the first conductive film and the third conductive film.

13. The semiconductor device according to claim 9, wherein the second conductive film is formed of one or a plurality of elements selected from Al, Ti, Cu, Au, Ag, Mo, Ni, Ta, Zr, and Co.

14. The semiconductor device according to claim 9, wherein the fourth conductive film is formed of one or a plurality of elements selected from Al, Ti, Cu, Au, Ag, Mo, Ni, Ta, Zr, and Co.

15. The semiconductor device according to claim 9, wherein the semiconductor film is any one of materials selected from zinc oxide, titanium oxide, magnesium zinc oxide, cadmium zinc oxide, cadmium oxide, InGaO₃(ZnO)₅, and a-IGZO.

16. The semiconductor device according to claim 9,

wherein the fourth conductive film does not overlap with the semiconductor film.

17. A semiconductor device comprising:

a first conductive film;

a second conductive film;

a first insulating film over the first conductive film and the second conductive film;

a semiconductor film provided over the first insulating film;

a third conductive film over the semiconductor film;

a fourth conductive film over the third conductive film;

a second insulating film covering the semiconductor film, the third conductive film and the fourth conductive film;

a pixel electrode provided over the second insulating film and electrically connected to the semiconductor film;

a transistor using a first portion of the first conductive film as a gate electrode, a first portion of the third conductive film as a source electrode and a first portion of the first insulating film as a gate dielectric; and

a storage capacitor using a second portion of the third conductive film as an upper electrode, a second portion of the first conductive film as a lower electrode, and a second portion of the first insulating film as a dielectric,

wherein an entirety of the second conductive film overlaps with the first conductive film while the first portion of the first conductive film and the second portion of the first conductive film do not overlap with the second conductive film,

wherein an entirety of the fourth conductive film overlaps with the third conductive film while the first portion of the third conductive film and the second portion of the third conductive film do not overlap with the fourth conductive film, and

wherein the storage capacitor is transparent such that a light passes through the storage capacitor from one of the first insulating film and the second insulating film to the other of the first insulating film and the second insulating film.

18. The semiconductor device according to claim 17, wherein the first conductive film and the third conductive film have a light-transmitting property.

19. The semiconductor device according to claim 17, wherein the second conductive film and the fourth conductive film have a light-shielding property.

20. The semiconductor device according to claim 17, wherein the second conductive film and the fourth conductive film have higher conductivity than the first conductive film and the third conductive film.

21. The semiconductor device according to claim 17, wherein the second conductive film is formed of one or a plurality of elements selected from Al, Ti, Cu, Au, Ag, Mo, Ni, Ta, Zr, and Co.

22. The semiconductor device according to claim 17, wherein the fourth conductive film is formed of one or a plurality of elements selected from Al, Ti, Cu, Au, Ag, Mo, Ni, Ta, Zr, and Co.

23. The semiconductor device according to claim 17, wherein the semiconductor film is any one of materials selected from zinc oxide, titanium oxide, magnesium zinc oxide, cadmium zinc oxide, cadmium oxide, InGaO₃(ZnO)₅, and a-IGZO.

24. The semiconductor device according to claim 17, wherein the fourth conductive film does not overlap with the semiconductor film.