Display device and method for manufacturing the same

• US 8,658,448 B2
• Filed: 12/01/2011
• Issued: 02/25/2014
• Est. Priority Date: 12/10/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kuwabara, Hideaki
• Primary Examiner(s): Malsawma, Lex
• Application Number:
  US13/308,607
• Publication Number:
  US 20120146035A1
• Time in Patent Office: 817 Days
• Field of Search: 438/34
• US Class Current: 438/34
• 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 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 29/41733 for thin film transistors with insulated gate
• CPC Class Codes: H01L 29/42384 for thin film field effect transistors, e.g. characterised by the thickness or the shape of the insulator or the dimensions, the shape or the lay-out of the conductor
• CPC Class Codes: H01L 29/78606 with supplementary region or layer in the thin film or in the insulated bulk substrate supporting it for controlling or increasing the safety of the device H01L29/78642, H01L29/78645 take precedence

Abstract

A conductive layer to be a gate electrode, an insulating layer to be a gate insulating layer, a semiconductor layer, and an insulating layer to be a channel protective layer, which are each included in a transistor, are successively formed without exposure to the air. A gate electrode (including another electrode or a wiring which is formed in the same layer) and an island-like semiconductor layer are formed through one photolithography step. A display device is manufactured through four photolithography steps including the photolithography step, a photolithography step of forming a contact hole, a photolithography step of forming a source electrode and a drain electrode (including another electrode or a wiring which is formed in the same layer), and a photolithography step of forming a pixel electrode (including another electrode or a wiring which are formed in the same layer).

Claims

1. A method for manufacturing a display device comprising the steps of:

forming a conductive layer, a first insulating layer, a semiconductor layer, and a second insulating layer;

forming a gate electrode and an island-like semiconductor layer by selective removal of the conductive layer, the first insulating layer, the semiconductor layer, and the second insulating layer through a first photolithography step;

exposing a portion of the island-like semiconductor layer by selective removal of a portion of the second insulating layer through a second photolithography step;

forming a source electrode and a drain electrode through a third photolithography step; and

forming a pixel electrode through a fourth photolithography step.

2. The method for manufacturing the display device, according to claim 1, wherein the conductive layer, the first insulating layer, the semiconductor layer, and the second insulating layer are formed without exposure to the air.

3. The method for manufacturing the display device, according to claim 1, wherein an oxide semiconductor is used for the semiconductor layer.

4. The method for manufacturing the display device, according to claim 1, wherein the gate electrode, the source electrode, or the drain electrode comprises a material containing copper.

5. The method for manufacturing the display device, according to claim 1, wherein a maximum process temperature after the gate electrode, the source electrode, or the drain electrode is formed is lower than or equal to 450°

C.

6. A method for manufacturing a display device comprising the steps of:

forming a conductive layer, a first insulating layer, a semiconductor layer, and a second insulating layer;

forming a gate electrode, a capacitor wiring, and an island-like semiconductor layer by selective removal of the conductive layer, the first insulating layer, the semiconductor layer, and the second insulating layer through a first photolithography step;

forming a third insulating layer covering the gate electrode, the capacitor wiring, and the island-like semiconductor layer;

exposing a portion of the island-like semiconductor layer by selective removal of a portion of the second insulating layer and the third insulating layer through a second photolithography step;

forming a source electrode and a drain electrode through a third photolithography step; and

forming a pixel electrode through a fourth photolithography step,

wherein a portion of the drain electrode overlaps with the third insulating layer and the capacitor wiring.

7. The method for manufacturing the display device, according to claim 6, wherein the conductive layer, the first insulating layer, the semiconductor layer, and the second insulating layer are formed without exposure to the air.

8. The method for manufacturing the display device, according to claim 6, wherein an oxide semiconductor is used for the semiconductor layer.

9. The method for manufacturing the display device, according to claim 6, wherein the gate electrode, the source electrode, or the drain electrode comprises a material containing copper.

10. The method for manufacturing the display device, according to claim 6, wherein a maximum process temperature after the gate electrode, the source electrode, or the drain electrode is formed is lower than or equal to 450°

C.