Semiconductor device and manufacturing method thereof

• US 9,368,514 B2
• Filed: 06/12/2015
• Issued: 06/14/2016
• 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 DINH
• Application Number:
  US14/737,672
• Publication Number:
  US 20150357352A1
• Time in Patent Office: 368 Days
• Field of Search: 257/57, 257/59, 257/72, 257/300
• US Class Current: 1/1
• 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

[Problem]

A TFT is manufactured using at least five photomasks in a conventional liquid crystal display device, and therefore the manufacturing cost is high.

[Solving Means]

By performing the formation of the pixel electrode 127, the source region 123 and the drain region 124 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.

Claims

1. A display device comprising:

a thin film transistor over a substrate, the thin film transistor comprising a gate electrode over the substrate, a gate insulating film over the gate electrode;

a capacitor wiring line over the substrate, wherein the capacitor wiring line comprises a same material as the gate electrode;

a first insulating film over the capacitor wiring line;

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

a second insulating film comprising a resin over the thin film transistor and the first 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 configured to be connected with a flexible printed circuit, the terminal portion comprising;

a second conductive layer over the substrate, the second conductive layer comprising a same material as the gate electrode of the thin film transistor; and

a third conductive layer over and in electrical contact with the second conductive layer, wherein the third conductive layer extends beyond a side edge of the second conductive layer.

2. The display device according to claim 1, wherein the thin film transistor is a bottom gate type transistor in which a channel formation region is formed over the gate electrode.

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

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 first 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 first conductive layer.

8. A display device comprising:

a thin film transistor over a substrate, the thin film transistor comprising a gate electrode over the substrate, a gate insulating film over the gate electrode;

a capacitor wiring line over the substrate, wherein the capacitor wiring line comprises a same material as the gate electrode;

a first insulating film over the capacitor wiring line;

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

a second insulating film comprising a resin over the thin film transistor and the first 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 configured to be connected with a flexible printed circuit, the terminal portion comprising;

a second conductive layer over the substrate, the second conductive layer comprising a same material as the gate electrode of the thin film transistor; and

a third conductive layer over and in electrical contact with the second conductive layer, wherein the third conductive layer extends beyond a side edge of the second conductive layer,

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

9. The display device according to claim 8, wherein the thin film transistor is a bottom gate type transistor in which a channel formation region is formed over the gate electrode.

10. The display device according to claim 8, wherein the pixel electrode is in contact with the first conductive layer through a second hole in the second insulating film.

11. The display device according to claim 8, wherein the thin film transistor comprises a silicon film including a channel formation region.

12. The display device according to claim 8, further comprising a liquid crystal material adjacent to the pixel electrode.

13. The display device according to claim 8, wherein the first conductive layer is electrically connected to the drain of the thin film transistor through the pixel electrode.

14. The display device according to claim 8, wherein the reflective conductive film directly contacts the first conductive layer.

15. A display device comprising:

a thin film transistor over a substrate, the thin film transistor comprising a gate electrode over the substrate, a gate insulating film over the gate electrode;

a gate wiring over the substrate, wherein the gate electrode is electrically connected to the gate wiring;

a capacitor wiring line over the substrate, wherein the capacitor wiring line extends in parallel with the gate wiring and overlaps with the gate wiring;

a first insulating film over the capacitor wiring line;

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

a second insulating film comprising a resin over the thin film transistor and the first 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 configured to be connected with a flexible printed circuit, the terminal portion comprising;

a second conductive layer over the substrate, the second conductive layer comprising a same material as the gate electrode of the thin film transistor; and

a third conductive layer over and in electrical contact with the second conductive layer, wherein the third conductive layer extends beyond a side edge of the second conductive layer.

16. The display device according to claim 15, wherein the thin film transistor is a bottom gate type transistor in which a channel formation region is formed over the gate electrode.

17. The display device according to claim 15, wherein the pixel electrode is in contact with the first conductive layer through a second hole in the second insulating film.

18. The display device according to claim 15, wherein the thin film transistor comprises a silicon film including a channel formation region.

19. The display device according to claim 15, further comprising a liquid crystal material adjacent to the pixel electrode.

20. The display device according to claim 15, wherein the first conductive layer is electrically connected to the drain of the thin film transistor through the pixel electrode.