Liquid crystal display device and electronic device

• US 7,872,722 B2
• Filed: 10/24/2007
• Issued: 01/18/2011
• Est. Priority Date: 10/31/2006
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kimura, Hajime
• Primary Examiner(s): Nelms; David
• Assistant Examiner(s): Duong; Tai
• Application Number:
  US11/923,128
• Publication Number:
  US 20080136990A1
• Time in Patent Office: 1,182 Days
• Field of Search: 349/42, 349/43, 349/113, 349/114, 349/141, 349/187, 257/59, 257/72, 345/92, 438/30
• US Class Current: 349/141
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/1337 Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: G02F 1/136231 for reducing the number of lithographic steps
• CPC Class Codes: G02F 1/136277 formed on a semiconductor substrate, e.g. of silicon
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G09G 2300/0876 Supplementary capacities in pixels having special driving circuits and electrodes instead of being connected to common electrode or ground; Use of additional capacitively coupled compensation electrodes
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/024 Scrolling of light from the illumination source over the display in combination with the scanning of the display screen
• CPC Class Codes: G09G 2310/027 Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
• CPC Class Codes: G09G 2310/0275 Details of drivers for data electrodes, other than drivers for liquid crystal, plasma or OLED displays, not related to handling digital grey scale data or to communication of data to the pixels by means of a current
• CPC Class Codes: G09G 2310/0297 Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2320/106 Determination of movement vectors or equivalent parameters within the image
• CPC Class Codes: G09G 2340/0435 : Change or adaptation of the frame rate of the video stream
• CPC Class Codes: G09G 2340/16 : Determination of a pixel data signal depending on the signal applied in the previous frame
• CPC Class Codes: G09G 2352/00 : Parallel handling of streams of display data
• CPC Class Codes: G09G 3/20 : for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/342 : using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
• CPC Class Codes: G09G 3/3659 : the addressing of the pixel involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependant on signal of two data electrodes
• CPC Class Codes: G09G 3/3685 : Details of drivers for data electrodes
• 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 27/1218 : with a particular composition or structure of the substrate
• CPC Class Codes: H04N 9/3102 : using two-dimensional electronic spatial light modulators micromechanical modulators as such G02B26/0833; liquid crystal modulators as such G02F1/13

Abstract

To provide a semiconductor device, a liquid crystal display device, and an electronic device which have a wide viewing angle and in which the number of manufacturing steps, the number of masks, and manufacturing cost are reduced compared with a conventional one. The liquid crystal display device includes a first electrode formed over an entire surface of one side of a substrate; a first insulating film formed over the first electrode; a thin film transistor formed over the first insulating film; a second insulating film formed over the thin film transistor; a second electrode formed over the second insulating film and having a plurality of openings; and a liquid crystal over the second electrode. The liquid crystal is controlled by an electric field between the first electrode and the second electrode.

Claims

1. A liquid crystal display device comprising:

a first electrode formed over an entire surface of one side of a substrate;

a first insulating film formed over the first electrode;

a thin film transistor formed over the first insulating film;

a second insulating film formed over the thin film transistor, wherein the second insulating film has an opening;

a third insulating film formed over the second insulating film and in the opening of the second insulating film;

a second electrode formed over the third insulating film, wherein the second electrode has a plurality of openings over the opening of the second insulating film and is electrically connected to the thin film transistor; and

a liquid crystal over the second electrode,

wherein the liquid crystal is controlled by an electric field between the first electrode and the second electrode.

2. The liquid crystal display device according to claim 1, wherein the first electrode and the second electrode are light-transmitting conductive films.

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

wherein one of the first electrode and the second electrode is a light-transmitting conductive film;

and

the other of the first electrode and the second electrode is a reflective conductive film.

4. An electronic device provided with the liquid crystal display device according to claim 1.

5. A liquid crystal display device comprising:

a first electrode formed over an entire surface of one side of a substrate;

a first insulating film formed over the first electrode;

a thin film transistor formed over the first insulating film;

the thin film transistor comprising;

a semiconductor film formed over the first electrode;

a gate insulating film formed over the semiconductor film;

a gate electrode formed over the gate insulating film;

a second insulating film formed over the gate electrode, wherein the second insulating film has an opening;

a third insulating film formed over the second insulating film and in the opening of the second insulating film;

a second electrode formed over the third insulating film, wherein the second electrode has a plurality of openings over the opening of the second insulating film and is electrically connected to the thin film transistor; and

a liquid crystal over the second electrode,

wherein the liquid crystal is controlled by an electric field between the first electrode and the second electrode.

6. The liquid crystal display device according to claim 5, wherein the first electrode and the second electrode are light-transmitting conductive films.

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

wherein one of the first electrode and the second electrode is a light-transmitting conductive film;

and

the other of the first electrode and the second electrode is a reflective conductive film.

8. An electronic device provided with the liquid crystal display device according to claim 5.

9. A liquid crystal display device comprising:

a first electrode formed over an entire surface of one side of a substrate;

a first insulating film formed over the first electrode;

a thin film transistor formed over the first insulating film;

the thin film transistor comprising;

a gate electrode formed over the first electrode;

a gate insulating film formed over the gate electrode;

a semiconductor film formed over the gate insulating film;

a second insulating film formed over the semiconductor film, wherein the second insulating film has an opening;

a third insulating film formed over the second insulating film and in the opening of the second insulating film;

a second electrode formed over the third insulating film, wherein the second electrode has a plurality of openings over the opening of the second insulating film and is electrically connected to the thin film transistor; and

a liquid crystal over the second electrode,

wherein the liquid crystal is controlled by an electric field between the first electrode and the second electrode.

10. The liquid crystal display device according to claim 9, wherein the first electrode and the second electrode are light-transmitting conductive films.

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

wherein one of the first electrode and the second electrode is a light-transmitting conductive film;

and

the other of the first electrode and the second electrode is a reflective conductive film.

12. An electronic device provided with the liquid crystal display device according to claim 9.

13. A liquid crystal display device comprising:

a first electrode formed over an entire surface of one side of a substrate;

a first insulating film formed over the first electrode;

a thin film transistor formed over the first insulating film, the thin film transistor comprising a semiconductor film;

a second insulating film formed over the thin film transistor;

a second electrode formed over the second insulating film, wherein the second electrode has a plurality of openings and is directly connected to the semiconductor film; and

a liquid crystal over the second electrode,

wherein the liquid crystal is controlled by an electric field between the first electrode and the second electrode.

14. The liquid crystal display device according to claim 13, wherein the first electrode and the second electrode are light-transmitting conductive films.

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

wherein one of the first electrode and the second electrode is a light-transmitting conductive film;

and

the other of the first electrode and the second electrode is a reflective conductive film.

16. An electronic device provided with the liquid crystal display device according to claim 13.

17. The liquid crystal display device according to claim 13, wherein the thin film transistor is a top-gate thin film transistor.

18. A method for manufacturing a liquid crystal display device, comprising the steps of:

forming a first electrode over a first substrate;

forming a first insulating film over the first electrode without patterning the first electrode;

forming a thin film transistor over the first insulating film;

forming a second insulating film over the thin film transistor, wherein the second insulating film has an opening;

forming a third insulating film over the second insulating film and in the opening of the second insulating film;

forming a second electrode electrically connected to the thin film transistor over the third insulating film, wherein the second electrode has a plurality of openings over the opening of the second insulating film; and

attaching a second substrate to the first substrate with a liquid crystal therebetween.

19. The method according to claim 18, wherein the first electrode and the second electrode are light-transmitting conductive films.

20. The method according to claim 18,

wherein one of the first electrode and the second electrode is a light-transmitting conductive film;

and

the other of the first electrode and the second electrode is a reflective conductive film.

21. The method according to claim 18, wherein the liquid crystal display device is provided for an electronic device.

22. A liquid crystal display device comprising:

a first electrode formed over an entire surface of one side of a substrate;

a first insulating film formed over the first electrode;

a thin film transistor formed over the first insulating film;

a second insulating film formed over the thin film transistor;

a second electrode formed over the second insulating film, wherein the second electrode has a plurality of openings and is electrically connected to the thin film transistor; and

a liquid crystal over the second electrode,

wherein the liquid crystal is controlled by an electric field between the first electrode and the second electrode, and

wherein a distance between the first electrode and the second electrode in a first region is smaller than that in a second region.

23. The liquid crystal display device according to claim 22, wherein the first electrode and the second electrode are light-transmitting conductive films.

24. The liquid crystal display device according to claim 22,

wherein one of the first electrode and the second electrode is a light-transmitting conductive film;

and

the other of the first electrode and the second electrode is a reflective conductive film.

25. An electronic device provided with the liquid crystal display device according to claim 22.

26. The liquid crystal display device according to claim 22, wherein the thin film transistor is located in the second region.

27. The liquid crystal display device according to claim 22, wherein the second insulating film has an opening in the first region.