Semiconductor device and manufacturing method thereof

• US 8,198,630 B2
• Filed: 05/27/2010
• Issued: 06/12/2012
• Est. Priority Date: 03/08/2000
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Kuwabara, Hideaki, Arai, Yasuyuki
• Primary Examiner(s): Hoang, Quoc
• Application Number:
  US12/789,382
• Publication Number:
  US 20100238393A1
• Time in Patent Office: 747 Days
• Field of Search: 257/57, 257/72, 257/300, 257/59, 257/E27.131, 257/E27.132
• US Class Current: 257/59
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/1339 Gaskets; Spacers; Sealing of cells
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/13452 Conductors connecting driver circuitry and terminals of panels
• CPC Class Codes: G02F 1/13458 Terminal pads
• CPC Class Codes: G02F 1/136204 Arrangements to prevent high voltage or static electricity failures
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/136231 for reducing the number of lithographic steps
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/136295 Materials; Compositions; Manufacture processes
• 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: G02F 2202/103 a-Si
• CPC Class Codes: G02F 2202/105 single crystal Si
• CPC Class Codes: G02F 2202/28 Adhesive materials or arrangements
• CPC Class Codes: H01L 21/67161 characterized by the layout of the process chambers
• CPC Class Codes: H01L 21/67167 surrounding a central transfer chamber
• CPC Class Codes: H01L 21/67207 comprising a chamber adapted to a particular process
• CPC Class Codes: H01L 21/67225 comprising at least one lithography chamber lithographic apparatuses G03F7/00
• CPC Class Codes: H01L 21/67236 : the substrates being processed being not semiconductor wafers, e.g. leadframes or chips
• CPC Class Codes: H01L 27/1218 : with a particular composition or structure of the substrate
• CPC Class Codes: H01L 27/1222 : with a particular composition, shape or crystalline structure of the active layer
• 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 27/1244 : for preventing breakage, peeling or short circuiting
• 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 29/66765 : Lateral single gate single channel transistors with inverted structure, i.e. the channel layer is formed after the gate
• CPC Class Codes: H01L 29/78669 : with inverted-type structure, e.g. with bottom gate

Abstract

A TFT is manufactured using at least five photomasks in a conventional liquid crystal display device, and therefore the manufacturing cost is high. By performing the formation of the pixel electrode, the source region and the drain region by using three photomasks in three photolithography steps, a liquid crystal display device prepared with a pixel TFT portion, having a reverse stagger type n-channel TFT, and a storage capacitor can be realized, FIG. 2.

Claims

1. A display device comprising:

a thin film transistor formed over a substrate;

a capacitor wiring line formed over the substrate;

a conductive layer formed over the substrate and electrically connected to a drain of the thin film transistor wherein a capacitor is formed between the capacitor wiring line and the conductive layer with at least a first insulating film interposed therebetween;

a second insulating film comprising a resin over the thin film transistor and the conductive layer wherein at least a portion of the second insulating film has a roughened upper surface;

a pixel electrode including a reflective conductive film over the second insulating film and electrically connected to the conductive layer through a hole in the second insulating film wherein at least a portion of the reflective conductive film has a rough surface due to the roughened upper surface of the second insulating film; and

a terminal portion electrically connected to a gate electrode of the thin film transistor, the terminal portion comprising;

a first conductive layer over the substrate, the first conductive layer comprising a same material as the gate electrode; and

a second conductive layer over and in electrical contact with the first conductive layer.

2. The display device according to claim 1 wherein the pixel electrode is in contact with the conductive layer through a second hole in the second insulating film.

3. The display device according to claim 1 wherein the thin film transistor is a bottom gate type transistor.

4. The display device according to claim 1 wherein the thin film transistor comprises a silicon film including a channel formation region.

5. The display device according to claim 1 further comprising a liquid crystal material adjacent to the pixel electrode.

6. The display device according to claim 1 wherein the conductive layer is electrically connected to the drain of the thin film transistor through the pixel electrode.

7. The display device according to claim 1 wherein the reflective conductive film directly contacts the conductive layer.

8. The display device according to claim 1, further comprising an IC chip over the substrate, the IC chip being in electrical contact with the terminal portion.

9. The display device according to claim 1, further comprising a flexible printed circuit in electrical contact with the terminal portion.

10. A display device comprising:

a gate electrode formed over a substrate;

a capacitor wiring line formed over the substrate;

a first insulating film formed over the gate electrode and the capacitor wiring line;

a first semiconductor layer including a channel formation region over the gate electrode with the first insulating film interposed therebetween;

a pair of second semiconductor layers containing an impurity element which impart n-type conductivity thereto, over the first semiconductor layer;

a first conductive layer formed on one of the pair of second semiconductor layers;

a second conductive layer formed over the capacitor wiring line with at least the first insulating film interposed therebetween to form a capacitor between the second conductive layer and the capacitor wiring line wherein the second conductive layer is electrically connected to the first conductive layer;

a second insulating film comprising a resin over the first conductive layer and the second conductive layer, wherein at least a portion of the second insulating film has a roughened upper surface;

a pixel electrode including a reflective conductive film over the second insulating film and electrically connected to the first conductive layer through a hole in the second insulating film wherein at least a portion of the reflective conductive film has a rough surface due to the roughened upper surface of the second insulating film; and

a terminal portion electrically connected to the gate electrode, the terminal portion comprising;

a third conductive layer over the substrate, the third conductive layer comprising a same material as the gate electrode; and

a fourth conductive layer over and in electrical contact with the third conductive layer.

11. The display device according to claim 10 wherein the pixel electrode is in contact with the first conductive layer through a second hole in the second insulating film.

12. The display device according to claim 10 wherein the first semiconductor layer comprises silicon.

13. The display device according to claim 10 further comprising a liquid crystal material adjacent to the pixel electrode.

14. The display device according to claim 10 wherein the second conductive layer is electrically connected to the first conductive layer through the pixel electrode.

15. The display device according to claim 10 wherein the reflective conductive film directly contacts the second conductive layer.

16. The display device according to claim 10, further comprising an IC chip over the substrate, the IC chip being in electrical contact with the terminal portion.

17. The display device according to claim 10, further comprising a flexible printed circuit in electrical contact with the terminal portion.

18. A display device comprising:

a gate electrode formed over a substrate;

a capacitor wiring line formed over the substrate;

a first insulating film formed over the gate electrode and the capacitor wiring line;

a first semiconductor layer including a channel formation region over the gate electrode with the first insulating film interposed therebetween;

a pair of second semiconductor layers containing an impurity element which impart n-type conductivity thereto, over the first semiconductor layer;

a first conductive layer formed on one of the pair of second semiconductor layers;

a second conductive layer formed over the capacitor wiring line with at least the first insulating film interposed therebetween to form a capacitor between the second conductive layer and the capacitor wiring line wherein the second conductive layer is electrically connected to the first conductive layer;

a second insulating film comprising a resin over the first conductive layer and the second conductive layer, wherein at least a portion of the second insulating film has a roughened upper surface; and

a pixel electrode including a reflective conductive film over the second insulating film and electrically connected to the first conductive layer through a hole in the second insulating film wherein at least a portion of the reflective conductive film has a rough surface due to the roughened upper surface of the second insulating film; and

a terminal portion electrically connected to the gate electrode, the terminal portion comprising;

a third conductive layer over the substrate, the third conductive layer comprising a same material as the gate electrode; and

a fourth conductive layer over and in electrical contact with the third conductive layer,

wherein the third conductive layer, the gate electrode and the capacitor wiring line are formed by patterning a first conductive film, and

wherein the second conductive layer and the first conductive layer are formed by patterning a second conductive film.

19. The display device according to claim 18 wherein the pixel electrode is in contact with the first conductive layer through a second hole in the second insulating film.

20. The display device according to claim 18 wherein the first semiconductor layer comprises silicon.

21. The display device according to claim 18 further comprising a liquid crystal material adjacent to the pixel electrode.

22. The display device according to claim 18 wherein the second conductive layer is electrically connected to the first conductive layer through the pixel electrode.

23. The display device according to claim 18 wherein the reflective conductive film directly contacts the second conductive layer.

24. The display device according to claim 18, further comprising an IC chip over the substrate, the IC chip being in electrical contact with the terminal portion.

25. The display device according to claim 18, further comprising a flexible printed circuit in electrical contact with the terminal portion.

26. The display device according to claim 18, wherein the first conductive film is a single layer.

27. The display device according to claim 18, wherein the second conductive film is a single layer.