Semiconductor device

Patent metadata

Field	Value
Publication number	US-9614095-B2
Application number	US-201213568451-A
Country	US
Kind code	B2
Filing date	Aug 7, 2012
Priority date	Aug 18, 2011
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

An oxide semiconductor transistor comprising an oxide semiconductor layer with high conductivity is provided. A semiconductor device including an oxide semiconductor layer comprising an oxide containing indium, gallium, and zinc (IGZO) and a particle of indium oxide; a gate electrode overlapping with a channel formation region in the oxide semiconductor layer with a gate insulating film interposed therebetween; and a source electrode and a drain electrode overlapping with a source region and a drain region in the oxide semiconductor layer. The semiconductor device may be a top-gate oxide semiconductor transistor or a bottom-gate oxide semiconductor transistor. The oxide semiconductor layer may be formed over or below the source electrode and the drain electrode.

First claim

What is claimed is:

1. A semiconductor device comprising:
a gate electrode;
a gate insulating film covering the gate electrode;
an oxide semiconductor layer comprising an oxide containing indium, gallium, and zinc and including a particle of indium oxide represented by In 2 O 3 , wherein the oxide semiconductor layer overlaps with the gate electrode with the gate insulating film interposed therebetween; and
a source electrode and a drain electrode over a source region and a drain region in the oxide semiconductor layer,
wherein the particle has a wedge shape.

2. The semiconductor device according to claim 1 , wherein the oxide semiconductor layer is included in a channel-etch transistor.

3. The semiconductor device according to claim 1 , further comprising a substrate and a base insulating film below the gate electrode.

4. The semiconductor device according to claim 1 , wherein a tip of the wedge shape is in a direction apart from a top surface of the oxide semiconductor layer.

5. A semiconductor device comprising:
a gate electrode over a substrate;
an oxide semiconductor layer including a channel formation region, a source region, and a drain region, the channel formation region being adjacent to the gate electrode with a gate insulating film interposed therebetween; and
a source electrode and a drain electrode being in contact with the source region and the drain region,
wherein the oxide semiconductor layer comprises an oxide containing indium, gallium, and zinc and includes a particle of indium oxide represented by In 2 O 3 ,
wherein the oxide semiconductor layer includes:
a first portion containing indium, gallium, zinc and oxygen; and
a second portion,

wherein a density of indium in the second portion is lower than a density of indium in the first portion,
wherein a density of oxygen in the second portion is lower than a density of oxygen in the first portion,
wherein the second portion has higher conductivity than other portions of the oxide semiconductor layer, and
wherein the particle has a wedge shape.

6. The semiconductor device according to claim 5 , further comprising a base insulating film on the substrate.

7. The semiconductor device according to claim 5 , wherein the oxide semiconductor layer covers the gate electrode.

8. The semiconductor device according to claim 5 , wherein the source electrode and the drain electrode are provided on the source region and the drain region, respectively.

9. The semiconductor device according to claim 5 , wherein a tip of the wedge shape is in a direction apart from a top surface of the oxide semiconductor layer.

10. A semiconductor device comprising:
a gate electrode over a substrate;
an oxide semiconductor layer including a channel formation region, a source region, and a drain region, the channel formation region being adjacent to the gate electrode with a gate insulating film interposed therebetween; and
a source electrode and a drain electrode being in electrical contact with the source region and the drain region,
wherein the oxide semiconductor layer comprises an oxide containing indium, gallium, and zinc and includes a particle of indium oxide,
wherein the oxide semiconductor layer includes:
a first portion containing indium, gallium, zinc and oxygen; and
a second portion,

wherein a density of indium in the second portion is lower than a density of indium in the first portion,
wherein a density of oxygen in the second portion is lower than a density of oxygen in the first portion,
wherein the second portion has higher conductivity than other portions of the oxide semiconductor layer, and
wherein the particle has a wedge shape.

11. The semiconductor device according to claim 10 , further comprising a base insulating film on the substrate.

12. The semiconductor device according to claim 10 , wherein the oxide semiconductor layer covers the gate electrode.

13. The semiconductor device according to claim 10 , wherein the source electrode and the drain electrode are provided on the source region and the drain region, respectively.

14. The semiconductor device according to claim 10 , wherein the indium oxide is represented by In 2 O 3 .

15. The semiconductor device according to claim 10 , wherein a tip of the wedge shape is in a direction apart from a top surface of the oxide semiconductor layer.

Assignees

• Okazaki Kenichi
• Watanabe Masahiro
• Mashiyama Mitsuo
• Semiconductor Energy Lab

Inventors

• Okazaki Kenichi
• Watanabe Masahiro
• Mashiyama Mitsuo

Classifications

• H10D30/6755 Primary

  Oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate · CPC title

• H01L29/7869 Primary

  Electricity · mapped topic

• H10P14/3434

  being oxide semiconductor materials (Group IIB-VIA semiconductor materials H10P14/3424) · CPC title