Semiconductor device and manufacturing method thereof
AssigneeMitsubishi Electric Corporation
InventorsKenichi Ootsuka, Tetsuya Takami, Tadaharu Minato
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Abstract
In a MOSFET using SiC a p-type channel is formed by epitaxial growth, so that the depletion layer produced in the p-type region right under the channel is reduced, even when the device is formed in a self-aligned manner. Thus, a high breakdown voltage is obtained. Also, since the device is formed in a self-aligned manner, the device size can be reduced so that an increased number of devices can be fabricated in a certain area and the on-state resistance can be reduced.
Claims9
A semiconductor device comprising:
- a semiconductor substrate having a first conductivity type;
- a drift layer having the first conductivity type and located on a main surface of said semiconductor substrate;
- a base region having a second conductivity type and located in a predetermined portion of a surface portion of said drift layer, said base region having a predetermined depth;
- a source region having the first conductivity type and located in a predetermined portion of a surface portion of said base region, said source region having a depth shallower than that of said base region;
- a channel region having the second conductivity type and located on a surface of said source region and said drift layer to connect said source region and said drift layer;
- an insulating film located on a surface of said channel region;
- a gate electrode located on a surface of said insulating film;
- a source electrode located on a surface of said base region and said source region;
- and
- a drain electrode formed on a lower surface of said semiconductor substrate.
A method of manufacturing a semiconductor device comprising:
- forming a drift layer of a first conductivity type on a main surface of a semiconductor substrate of the first conductivity type;
- forming a base region of a second conductivity type in a predetermined portion of a surface portion of said drift layer, said base region having a predetermined depth;
- forming a source region of the first conductivity type in a predetermined portion of a surface portion of said base region, said source region having a depth shallower than that of said base region;
- and
- forming a channel region of the second conductivity type by epitaxial growth on a surface of said source region and said drift layer.
A method of manufacturing a semiconductor device comprising:
- forming a drift layer of a first conductivity type on a main surface of a semiconductor substrate of the first conductivity type;
- forming a layer of a second conductivity type over an entire surface of said drift layer;
- forming a base region of the second conductivity type in a predetermined portion of a surface portion of said layer of the second conductivity type, said base region having a predetermined depth;
- forming a source region of the first conductivity type in a predetermined portion of a surface portion of said base region, said source region having a depth shallower than that of said base region;
- forming a depletion region in a predetermined portion of the surface portion of said layer of the second conductivity type, said depletion region having an increased impurity concentration;
- forming, in a predetermined portion of the surface portion of said layer of the second conductivity type, a region having a higher impurity concentration than said base region in order to make contact with a source electrode;
- and
- forming a channel region of the second conductivity type by epitaxial growth on a surface of said source region and said depletion region.
Dependencies are inferred from the claim text.