Semiconductor device and manufacturing method thereof
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorShunpei Yamazaki
Life of this patent
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Abstract
A semiconductor device capable of high speed operation is provided. Further, a semiconductor device in which change in electric characteristics due to a short channel effect is hardly caused is provided. An oxide semiconductor having crystallinity is used for a semiconductor layer of a transistor. A channel formation region, a source region, and a drain region are formed in the semiconductor layer. The source region and the drain region are formed by self-aligned process in which one or more elements selected from Group 15 elements are added to the semiconductor layer with the use of a gate electrode as a mask. The source region and the drain region can have a wurtzite crystal structure.
Claims24
A semiconductor device comprising:
- an oxide semiconductor layer including a channel formation region, a source region and a drain region,
- wherein:
- the oxide semiconductor layer contains zinc, indium and gallium;
- the channel formation region includes a crystal;
- the crystal is c-axis-oriented in a direction substantially perpendicular to a surface of the oxide semiconductor layer;
- the crystal comprises atoms arranged to have a triangular or hexagonal shape in an a-b plane;
- each of the source region and the drain region includes at least one element selected from Group 15 elements;
- each of the source region and the drain region comprises a wurtzite crystal structure, and
- a crystal structure of each of the source region and the drain region is different from a crystal structure of the channel formation region.
A semiconductor device comprising:
- an oxide semiconductor layer including a channel formation region, a source region and a drain region;
- a source electrode electrically connected to the source region;
- and
- a drain electrode electrically connected to the drain region,
- wherein:
- the channel formation region includes a crystal;
- the crystal is c-axis-oriented in a direction substantially perpendicular to a surface of the oxide semiconductor layer;
- the crystal comprises atoms arranged to have a triangular or hexagonal shape in an a-b plane;
- each of the source electrode and the drain electrode is a metal electrode;
- an energy gap of the channel formation region is larger than an energy gap of each of the source region and the drain region;
- the energy gap of the channel formation region is 2.5 eV or more, and
- a crystal structure of each of the source region and the drain region is different from a crystal structure of the channel formation region.
A semiconductor device comprising:
- an oxide semiconductor layer including a channel formation region, a source region and a drain region,
- wherein:
- the oxide semiconductor layer contains zinc, indium and gallium;
- the channel formation region includes a crystal;
- the crystal is c-axis-oriented in a direction substantially perpendicular to a surface of the oxide semiconductor layer;
- the crystal comprises atoms arranged to have a triangular or hexagonal shape in an a-b plane;
- each of the source region and the drain region includes at least one element selected from Group 15 elements;
- each of the source region and the drain region comprises a wurtzite crystal structure;
- an energy gap of the channel formation region is larger than an energy gap of each of the source region and the drain region;
- the energy gap of the channel formation region is 2.5 eV or more, and
- a crystal structure of each of the source region and the drain region is different from a crystal structure of the channel formation region.
A semiconductor device comprising:
- an oxide semiconductor layer including a channel formation region, a source region and a drain region,
- wherein:
- the oxide semiconductor layer contains zinc, indium and gallium;
- the channel formation region includes a crystal;
- each of the source region and the drain region includes at least one element selected from Group 15 elements;
- each of the source region and the drain region comprises a wurtzite crystal structure, and
- a crystal structure of each of the source region and the drain region is different from a crystal structure of the channel formation region.
Dependencies are inferred from the claim text.