Manufacturing method of thin film transistor substrate

• US 20050121673A1
• Filed: 01/11/2005
• Published: 06/09/2005
• Est. Priority Date: 05/10/2002
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Shiba, Takeo, Itoga, Toshihiko, Satou, Takeshi
• Granted Patent: US 7,323,716 B2
• Time in Patent Office: Days
• US Class Current: 257/66
• CPC Class Codes: H01L 27/1237 with a different composition, shape, layout or thickness of the gate insulator in different devices
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• 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 29/78621 with LDD structure or an extension or an offset region or characterised by the doping profile
• CPC Class Codes: H01L 29/78627 with a significant overlap between the lightly doped drain and the gate electrode, e.g. GOLDD
• CPC Class Codes: H01L 29/78645 with multiple gate

Abstract

This invention provides a manufacturing method for fabricating on the same substrate both high voltage thin film transistors suitable for driving liquid crystal and low voltage drive high performance thin film transistors. In addition, this invention provides a thin film transistor substrate where the area occupied by a storage capacitor in each pixel is reduced to raise the aperture ratio of the display unit. One aspect of this invention provides a manufacturing method characterized in that the impurity regions of both high voltage thin film transistors and high performance thin film transistors which differ in the thickness of gate insulation are formed by implanting a dopant through the same two-layered film. Another aspect of this invention reduces the area occupied by the drive circuit in the display unit by utilizing an extension of one layer of the insulation film included in each thin film transistor.

Claims

1-17. -17. (canceled)

18. A thin film transistor substrate comprising:

on an insulating substrate,

plural first wiring lines and plural second wiring lines which intersect each other,

plural pixels formed beside each point of intersection of said first and second wiring lines,

capacitors to retain a signal,

pixel switching devices,

at least part of a driver circuit to drive a device, wherein

said pixel switching devices comprise a first transistor including a gate insulation film containing a multi-layer of a first insulating film and a second insulating film,

said driver circuit comprises a second transistor including the first insulating film as a gate insulation film, and

said capacitor is arranged to retain a signal formed with the second insulation film extended from the gate insulation film.

19. A thin film transistor substrate according to claim 18, wherein said insulating substrate is a transparent insulating substrate.