US 2013/0075723 A1 · Semiconductor Device, Display Device, And Electronic Appliance

Abstract

In a channel protected thin film transistor in which a channel formation region is formed using an oxide semiconductor, an oxide semiconductor layer which is dehydrated or dehydrogenated by a heat treatment is used as an active layer, a crystal region including nanocrystals is included in a superficial portion in the channel formation region, and the rest portion is amorphous or is formed of a mixture of amorphousness/non-crystals and microcrystals, where an amorphous region is dotted with microcrystals. By using an oxide semiconductor layer having such a structure, a change to an n-type caused by entry of moisture or elimination of oxygen to or from the superficial portion and generation of a parasitic channel can be prevented and a contact resistance with a source and drain electrodes can be reduced.

Claims1

Dependent claims

A semiconductor device comprising:

a gate electrode layer;
a gate insulating layer over the gate electrode layer;
an oxide semiconductor layer over the gate insulating layer;
a first oxide insulating layer in contact with part of the oxide semiconductor layer;
and
a source electrode layer and a drain electrode layer in contact with part of the oxide semiconductor layer,
wherein a region of the oxide semiconductor layer located directly underneath a gap between the source electrode and the first oxide insulating layer, and a region of the oxide semiconductor layer located directly underneath a gap between the drain electrode and the first oxide insulating layer, each has a thickness less than a region overlapping with the source electrode layer, a region overlapping with the first oxide insulating layer, and a region overlapping with the drain electrode layer.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application

13/671,638Filed 8 Nov 2012

Priority

JP 2009-2344138 Oct 2009

Published

28 Mar 2013

Term ends

Not estimatedThe source records don’t support an estimate.

Classification8 codes

H10D 30/6755
Characterised by the active materials: oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate
H10D 30/6704
Thin-film transistors [TFT]: having supplementary regions or layers in the thin films or in the insulated bulk substrates for controlling…
H10D 30/6757
Thin-film transistors [TFT]: characterised by the structure of the channel, e.g. transverse or longitudinal shape or doping profile
H10D 62/405
Crystalline structures: orientations of crystalline planes

Semiconductor Device, Display Device, And Electronic Appliance

Life of this patent

Semiconductor Device, Display Device, And Electronic Appliance

Life of this patent

Abstract

Claims1