Semiconductor device
A semiconductor device according to the present invention includes a semiconductor layer of SiC of a first conductivity type, a plurality of body regions of a second conductivity type formed in the surface portion of the semiconductor layer with each body region forming a unit cell, a source region of the first conductivity type formed in the inner portion of the body region, a gate electrode facing the body region across a gate insulating film, a drain region of the first conductivity type and a collector region of the second conductivity type formed in the rear surface portion of the semiconductor layer such that the drain region and the collector region adjoin each other, and a drift region between the body region and the drain region, wherein the collector region is formed such that the collector region covers a region including at least two unit cells in the x-axis direction along the surface of the semiconductor layer.
1. A semiconductor device comprising:
a semiconductor layer of SiC of a first conductivity type;
a body region of a second conductivity type formed in the surface portion of the semiconductor layer;
a source region of the first conductivity type formed in the inner portion of the body region;
a gate electrode facing the body region across a gate insulating film;
a drain region of the first conductivity type and a collector region of the second conductivity type formed in the rear surface portion of the semiconductor layer, the drain region and the collector region adjoining each other; and
a drift region between the body region and the drain region; wherein
the upper end of the collector region is positioned closer to the surface of the semiconductor layer than the upper end of the drain region in the y-axis direction along the thickness direction of the semiconductor layer.
2. A semiconductor device according to claim 1 , wherein
the rear surface of a semiconductor layer extends across the interface between the drain region and the collector region to make both surfaces flush with each other.
3. A semiconductor device according to claim 1 , further comprising:
a field stop region formed to extend over the drain region and the collector region in the x-axis direction along the surface of the semiconductor layer, the field stop region being disposed between the drift region, and the drain region and the collector region.
4. A semiconductor device according to claim 1 , wherein
the semiconductor device includes a planar-gate structure where the gate electrode is disposed on the semiconductor layer.
5. A semiconductor device according to claim 1 , wherein
the semiconductor device includes a trench-gate structure where the gate electrode is embedded in a trench formed in the semiconductor layer.
6. A semiconductor device according to claim 1 , wherein
an x-axis width Wc of the collector region along the surface of the semiconductor layer is made narrower than the width of the body region.
7. A semiconductor device according to claim 1 , wherein
an x-axis width Wc of the collector region along the surface of the semiconductor layer is made wider than the width of the body region.
8. A semiconductor device according to claim 1 , wherein
a y-axis thickness Dp from the upper end of the drain region to the upper end of the collector region in the y-axis direction is 0 μm through 10 μm.
9. A semiconductor device according to claim 1 , further comprising:
a field stop region formed along the upper end and the lateral part of the collector region, and the upper end of the drain region.
10. A semiconductor device according to claim 3 , wherein the field stop region contains an n-type impurity.
11. A semiconductor device according to claim 1 , wherein a y-axis thickness Td of the drift region in the y-axis direction along the thickness direction of the semiconductor layer is 10 μm to 100 μm.