Semiconductor device and manufacturing method thereof
A semiconductor device includes: a layer of a first conductivity type; a well of a second conductivity type on the layer of the first conductivity type in an active region; and a flat RESURF layer of the second conductivity type on the layer of the first conductivity type on an outer circumference of the well as a termination structure. The RESURF layer includes a low concentration layer arranged at an inner end on the well side and an outer end on the outer circumferential side, and a high concentration layer arranged between the inner end and the outer end and having a higher impurity concentration than the low concentration layer.
1. A semiconductor device comprising:
a substrate including a layer of a first conductivity type;
a well of a second conductivity type on the layer of the first conductivity type in an active region in a center region of the substrate; and
a flat RESURF layer of the second conductivity type on the layer of the first conductivity type on an outer circumference of the well as a termination structure, wherein
the RESURF layer includes a low concentration layer arranged at an inner end on the well side and an outer end on the outer circumferential side, and a high concentration layer arranged between the inner end and the outer end and having a higher impurity concentration than the low concentration layer, and
the RESURF layer surrounds the active region.
2. The semiconductor device according to claim 1 , further comprising a plurality of field plates on the RESURF layer via an insulating film.
3. The semiconductor device according to claim 1 , wherein the RESURF layer includes a plurality of diffusion layers.
4. A semiconductor device comprising:
a layer of a first conductivity type;
a well of a second conductivity type on the layer of the first conductivity type in an active region; and
a flat RESURF layer of the second conductivity type on the layer of the first conductivity type on an outer circumference of the well as a termination structure, wherein
the RESURF layer includes a low concentration layer arranged at an inner end on the well side and an outer end on the outer circumferential side, and a high concentration layer arranged between the inner end and the outer end and having a higher impurity concentration than the low concentration layer,
the RESURF layer includes a plurality of diffusion layers, and
the diffusion layer making up the high concentration layer is wider than the diffusion layer making up the low concentration layer.
5. A semiconductor device comprising:
a layer of a first conductivity type;
a well of a second conductivity type on the layer of the first conductivity type in an active region; and
a flat RESURF layer of the second conductivity type on the layer of the first conductivity type on an outer circumference of the well as a termination structure, wherein
the RESURF layer includes a low concentration layer arranged at an inner end on the well side and an outer end on the outer circumferential side, and a high concentration layer arranged between the inner end and the outer end and having a higher impurity concentration than the low concentration layer,
the RESURF layer includes a plurality of diffusion layers, and
an interval of the diffusion layers making up the high concentration layer is narrower than an interval of the diffusion layers making up the low concentration layer.