Liquid crystal display device

• US 8,441,425 B2
• Filed: 11/24/2009
• Issued: 05/14/2013
• Est. Priority Date: 11/28/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Ishitani, Tetsuji, Kubota, Daisuke
• Primary Examiner(s): Edun, Muhammad N
• Application Number:
  US12/624,863
• Publication Number:
  US 20100134397A1
• Time in Patent Office: 1,267 Days
• Field of Search: None
• US Class Current: 345/92
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/136209 Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element
• CPC Class Codes: G02F 1/136222 Colour filters incorporated in the active matrix substrate
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes 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 27/1248 with a particular composition or shape of the interlayer dielectric specially adapted to the circuit arrangement
• 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 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

To provide a liquid crystal display device suitable for a thin film transistor which uses an oxide semiconductor. In a liquid crystal display device which includes a thin film transistor including an oxide semiconductor layer, a film having a function of attenuating the intensity of transmitting visible light is used as an interlayer film which covers at least the oxide semiconductor layer. As the film having a function of attenuating the intensity of transmitting visible light, a coloring layer can be used and a light-transmitting chromatic color resin layer is preferably used. An interlayer film which includes a light-transmitting chromatic color resin layer and a light-blocking layer may be formed in order that the light-blocking layer is used as a film having a function of attenuating the intensity of transmitting visible light.

Claims

1. A liquid crystal display device comprising:

a thin film transistor in which an oxide semiconductor layer overlapping with a gate electrode layer serves as a channel formation region;

a pixel electrode layer electrically connected to the thin film transistor;

an interlayer film between the thin film transistor and the pixel electrode layer; and

a liquid crystal layer over the thin film transistor, the pixel electrode layer, and the interlayer film,

wherein the interlayer film is a light-transmitting chromatic color resin layer which has a light transmittance lower than the oxide semiconductor layer,

wherein the light-transmitting chromatic color resin layer overlaps with the pixel electrode layer and covers the oxide semiconductor layer, and

wherein the liquid crystal layer includes a liquid crystal material exhibiting a blue phase.

2. The liquid crystal display device according to claim 1,

wherein the light-transmitting chromatic color resin layer has a plurality of colors, and

wherein each pixel includes the light-transmitting chromatic color resin layer having one color of the plurality of colors.

3. The liquid crystal display device according to claim 1,

wherein a light-blocking layer is over the thin film transistor with the liquid crystal layer interposed therebetween.

4. The liquid crystal display device according to claim 1,

wherein a common electrode layer is included between the interlayer film and the liquid crystal layer.

5. The liquid crystal display device according to claim 1,

wherein a common electrode layer is included below the interlayer film.

6. The liquid crystal display device according to claim 1,

wherein a common electrode layer is included between the interlayer film and the liquid crystal layer, and

wherein the pixel electrode layer and the common electrode layer have an opening pattern.

7. The liquid crystal display device according to claim 1,

wherein a common electrode layer is included between the interlayer film and the liquid crystal layer, and

wherein the pixel electrode layer and the common electrode layer have a comb-shape.

8. The liquid crystal display device according to claim 1,

wherein the oxide semiconductor layer includes at least one of indium, gallium, and zinc.

9. The liquid crystal display device according to claim 1,

wherein the liquid crystal layer includes a chiral agent.

10. The liquid crystal display device according to claim 1,

wherein the liquid crystal layer includes a photocurable resin and a photopolymerization initiator.

11. A liquid crystal display device comprising:

a thin film transistor in which an oxide semiconductor layer overlapping with a gate electrode layer serves as a channel formation region;

a pixel electrode layer electrically connected to the thin film transistor;

an interlayer film between the thin film transistor and the pixel electrode layer; and

a liquid crystal layer over the thin film transistor, the pixel electrode layer, and the interlayer film,

wherein the interlayer film includes a light-blocking layer and a light-transmitting chromatic color resin layer which has a light transmittance lower than the oxide semiconductor layer,

wherein the light-blocking layer covers the oxide semiconductor layer,

wherein the light-transmitting chromatic color resin layer overlaps with the pixel electrode layer, and

wherein the liquid crystal layer includes a liquid crystal material exhibiting a blue phase.

12. The liquid crystal display device according to claim 11,

wherein the light-blocking layer is a black resin.

13. The liquid crystal display device according to claim 11,

wherein the light-transmitting chromatic color resin layer has a plurality of colors, and

wherein each pixel includes the light-transmitting chromatic color resin layer having one color of the plurality of colors.

14. The liquid crystal display device according to claim 11,

wherein a light-blocking layer is over the thin film transistor with the liquid crystal layer interposed therebetween.

15. The liquid crystal display device according to claim 11,

wherein a common electrode layer is included between the interlayer film and the liquid crystal layer.

16. The liquid crystal display device according to claim 11,

wherein a common electrode layer is included below the interlayer film.

17. The liquid crystal display device according to claim 11,

wherein a common electrode layer is included between the interlayer film and the liquid crystal layer, and

wherein the pixel electrode layer and the common electrode layer have an opening pattern.

18. The liquid crystal display device according to claim 11,

wherein a common electrode layer is included between the interlayer film and the liquid crystal layer, and

wherein the pixel electrode layer and the common electrode layer have a comb-shape.

19. The liquid crystal display device according to claim 11,

wherein the oxide semiconductor layer includes at least one of indium, gallium, and zinc.

20. The liquid crystal display device according to claim 11,

wherein the liquid crystal layer includes a chiral agent.

21. The liquid crystal display device according to claim 11,

wherein the liquid crystal layer includes a photocurable resin and a photopolymerization initiator.