Semiconductor device and method for manufacturing same
AssigneeKabushiki Kaisha Toshiba
InventorsWataru Saito, Ichiro Omura
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Abstract
The present semiconductor device comprises pillar layers formed on a semiconductor substrate, the pillar layers comprising a first semiconductor pillar layer of a first conductivity type and a second semiconductor pillar layer of a second conductivity type which both have a strip cross section and are alternately formed on the semiconductor surface. A semiconductor base layer of the second conductivity type is selectively formed on one of the first semiconductor pillar layer and second semiconductor pillar layer. The semiconductor base layer has a flat impurity profile.
Claims18
A semiconductor device comprising:
- a semiconductor substrate of a first conductivity type;
- pillar layers formed on the semiconductor substrate, the pillar layers comprising a first semiconductor pillar layer of a first conductivity type and a second semiconductor pillar layer of a second conductivity type which both have a strip cross section and are alternately formed in a first direction along a surface of the semiconductor substrate;
- a first main electrode electrically connected to the first semiconductor substrate;
- a semiconductor base layer of the second conductivity type selectively formed on a surface of one of the first semiconductor pillar layer and second semiconductor pillar layer;
- a semiconductor diffusion layer of the first conductivity type selectively diffused into a surface of the semiconductor base layer;
- a second main electrode formed in contact with the semiconductor base layer and semiconductor diffusion layer;
- and
- a control electrode formed via an insulating film on a region over the semiconductor diffusion layer and first semiconductor pillar layer to form a channel between the semiconductor diffusion layer and first semiconductor pillar layer,
- the semiconductor base layer having an impurity profile which is flat at least in the first direction.
A method for manufacturing a semiconductor device comprising pillar layers formed on a first semiconductor layer of a first conductivity type, the pillar layers comprising a first semiconductor pillar layer of the first conductivity type and a second semiconductor pillar layer of a second conductivity type which are alternately formed in a first direction along a surface of the first semiconductor layer,
- the method comprising:
- growing an epitaxial layer for the pillar layers on the semiconductor substrate of the first conductivity type;
- forming a semiconductor base layer of the second conductivity type on the epitaxial layer over a whole area of a device region by diffusion;
- forming a trench which penetrates the semiconductor layer and reaches at least near a bottom of the epitaxial layer;
- depositing in the trench a semiconductor layer of an opposite conductivity type to the epitaxial layer to form the pillar layer;
- and
- forming a diffusion region, an insulating film, and an electrode in the semiconductor base layer divided by the trench to form the semiconductor device.
Dependencies are inferred from the claim text.