Semiconductor device and manufacturing method thereof

• US 8,237,167 B2
• Filed: 01/25/2012
• Issued: 08/07/2012
• Est. Priority Date: 12/25/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Primary Examiner(s): Smith, Zandra
• Assistant Examiner(s): DUONG, KHANH B
• Application Number:
  US13/357,958
• Publication Number:
  US 20120119214A1
• Time in Patent Office: 195 Days
• Field of Search: None
• US Class Current: 257/59
• 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 27/1225 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 27/1248 with a particular composition or shape of the interlayer dielectric specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/1288 employing particular masking sequences or specially adapted masks, e.g. half-tone mask
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• 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

An object is to reduce a capacitance value of parasitic capacitance without decreasing driving capability of a transistor in a semiconductor device such as an active matrix display device. Further, another object is to provide a semiconductor device in which the capacitance value of the parasitic capacitance was reduced, at low cost. An insulating layer other than a gate insulating layer is provided between a wiring which is formed of the same material layer as a gate electrode of the transistor and a wiring which is formed of the same material layer as a source electrode or a drain electrode.

Claims

1. A display device comprising:

a first wiring including a gate electrode;

a resist mask over a portion of the first wiring;

a semiconductor layer over the gate electrode;

a second wiring including a source electrode; and

a pixel electrode,

wherein the source electrode is electrically connected to the semiconductor layer,

wherein the pixel electrode is electrically connected to the semiconductor layer, and

wherein the second wiring crosses over the first wiring with the resist mask interposed therebetween.

2. The display device according to claim 1, wherein the semiconductor layer includes an oxide semiconductor material.

3. The display device according to claim 1, wherein the first wiring is wider than the second wiring.

4. The display device according to claim 1, wherein the display device is incorporated in one selected from the group consisting of an e-book reader, a television set, a digital photo frame, an amusement machine, and a cellular phone.

5. A display device comprising:

a first wiring including a gate electrode;

a resist mask over a portion of the first wiring;

a gate insulating layer over the first wiring and the resist mask;

a semiconductor layer over the gate insulating layer;

a second wiring including a source electrode; and

a pixel electrode,

wherein the source electrode is electrically connected to the semiconductor layer,

wherein the pixel electrode is electrically connected to the semiconductor layer, and

wherein the second wiring crosses over the first wiring with the resist mask and the gate insulating layer interposed therebetween.

6. The display device according to claim 5, wherein the semiconductor layer includes an oxide semiconductor material.

7. The display device according to claim 5, wherein the first wiring is wider than the second wiring.

8. The display device according to claim 5, wherein the display device is incorporated in one selected from the group consisting of an e-book reader, a television set, a digital photo frame, an amusement machine, and a cellular phone.

9. A display device comprising:

a first wiring including a gate electrode;

a resist mask over a portion of the first wiring;

a gate insulating layer over the first wiring and the resist mask;

a semiconductor layer over the gate insulating layer;

a second wiring including a source electrode;

a transparent conductive layer over a portion of the second wiring; and

a pixel electrode,

wherein the source electrode is electrically connected to the semiconductor layer,

wherein the pixel electrode is electrically connected to the semiconductor layer, and

wherein the second wiring and the transparent conductive layer cross over the first wiring with the resist mask and the gate insulating layer interposed therebetween.

10. The display device according to claim 9, wherein the pixel electrode is made of a same material as the transparent conductive layer.

11. The display device according to claim 9, wherein the semiconductor layer includes an oxide semiconductor material.

12. The display device according to claim 9, wherein the first wiring is wider than the second wiring.

13. The display device according to claim 9, wherein the display device is incorporated in one selected from the group consisting of an e-book reader, a television set, a digital photo frame, an amusement machine, and a cellular phone.