1. A semiconductor device comprising:
a semiconductor layer of a first conductivity type;
a first semiconductor pillar layer of the first conductivity type provided on a major surface of the semiconductor layer;
a second semiconductor pillar layer of a second conductivity type provided on the major surface of the semiconductor layer and adjoining the first semiconductor pillar layer;
a third semiconductor pillar layer of the first conductivity type provided on the major surface of the semiconductor layer and adjoining the second semiconductor pillar layer;
a forth semiconductor pillar layer of the second conductivity type provided on the major surface of the semiconductor layer and adjoining the third semiconductor pillar layer;
a fifth semiconductor pillar layer of the first conductivity type provided on the major surface of the semiconductor layer and adjoining the forth semiconductor pillar layer;
a first semiconductor base layer of the second conductivity type provided on the second semiconductor pillar layer;
a second semiconductor base layer of the second conductivity type provided on the forth semiconductor pillar layer;
a first semiconductor region of the first conductivity type selectively provided on a surface of the first semiconductor base layer;
a second semiconductor region of the first conductivity type selectively provided on a surface of the second semiconductor base layer;
a gate insulating film provided on the first semiconductor base layer between the first semiconductor region and the first semiconductor pillar layer and between the first semiconductor region and the third semiconductor pillar layer, and provided on the second semiconductor base layer between the second semiconductor region and the third semiconductor pillar layer and between the second semiconductor region and the fifth semiconductor pillar layer; and
a gate electrode provided on the gate insulating film,
each width of the first through fifth semiconductor pillar layers seen in a perpendicular direction to interfaces of p-n junctions formed among the first through fifth semiconductor pillar layers respectively being 10 microns or less.
2. The semiconductor device according to claim 1, wherein each of the first through fifth semiconductor pillar layers are formed in a substantially stripe fashion extending in a parallel direction to the major surface of the semiconductor layer.
3. The semiconductor device according to claim 1, wherein each interface of p-n junctions formed among the first through fifth semiconductor pillar layers are substantially perpendicular to the major surface of the semiconductor layer.
4. The semiconductor device according to claim 1, further comprising a semiconductor intermediate layer of the first conductivity type whose concentration of impurities is lower than the first, third, and fifth semiconductor pillar layers, provided on the major surface of the semiconductor layer in a surrounding of the first through fifth semiconductor pillar layers.
5. The semiconductor device according to claim 4, wherein the semiconductor intermediate layer is also provided on an outer edge of the major surface of the semiconductor layer.
6. The semiconductor device according to claim 1, wherein the first through fifth semiconductor pillar layers have been formed by epitaxial growth.
7. A semiconductor device comprising:
a semiconductor layer of a first conductivity type;
a first semiconductor pillar layer of the first conductivity type provided on a major surface of the semiconductor layer;
a second semiconductor pillar layer of a second conductivity type provided on the major surface of the semiconductor layer, adjoining and surrounding the first semiconductor pillar layer;
a third semiconductor pillar layer of the first conductivity type provided on the major surface of the semiconductor layer, adjoining and surrounding the second semiconductor pillar layer;
a semiconductor base layer of the second conductivity type provided on the second semiconductor pillar layer;
a semiconductor region of the first conductivity type selectively provided on a surface of the semiconductor base layer;
a gate insulating film provided on the semiconductor base layer between the semiconductor region and the first semiconductor pillar layer and between the semiconductor region and the third semiconductor pillar layer; and
a gate electrode provided on the gate insulating film,
each width of the first through third semiconductor pillar layers seen in a perpendicular direction to a interfaces of p-n junctions formed among the first through third semiconductor pillar layers respectively being 10 microns or less.
8. The semiconductor device according to claim 7, wherein each of the second and third semiconductor pillar layers is formed in a concentric circle fashion centering on the first semiconductor pillar layer.
9. The semiconductor device according to claim 7, wherein each of the second and third semiconductor pillar layers is formed in a concentric loop fashion centering on the first semiconductor pillar layer.
10. The semiconductor device according to claim 7, wherein each interface of p-n junctions formed among the first through third semiconductor pillar layers is substantially perpendicular to the major surface of the semiconductor layer.
11. The semiconductor device according to claim 7, further comprising a semiconductor intermediate layer of the first conductivity type whose concentration of impurities is lower than the first and third semiconductor pillar layers, provided on the major surface of the semiconductor layer in a surrounding of the third semiconductor pillar layer.
12. The semiconductor device according to claim 11, wherein the semiconductor intermediate layer is also provided on an outer edge of the major surface of the semiconductor layer.
13. The semiconductor device according to claim 7, wherein the first through third semiconductor pillar layers have been formed by epitaxial growth.
14. A manufacturing method of a semiconductor device comprising:
forming a trench in a first semiconductor layer of a first conductivity type;
introducing impurities of the first conductivity type into side walls of the trench;
growing a second semiconductor layer of a second conductivity type epitaxially on the side walls and on the bottom of the trench;
introducing the impurities of the first conductivity type into the second semiconductor layer on the bottom of the trench;
growing epitaxially a third semiconductor layer of the first conductivity type on the side walls and on the bottom of the trench covered by the second semiconductor layer;
forming a base layer of the second conductivity type in an upper part of the second semiconductor layer;
forming a region of the first conductivity type on a surface of the base layer selectively;
forming a gate insulating film on the base layer; and
forming a gate electrode on the gate insulating film.
15. The manufacturing method of a semiconductor device according to claim 14, wherein the introducing the impurities of the first conductivity type into the side walls of the trench includes ion implanting the impurity of the first conductivity type with a slant angle to the side walls of the trench.
16. The manufacturing method of a semiconductor device according to claim 14, wherein the introducing the impurities of the first conductivity type into the second semiconductor layer includes ion implanting the impurity of the first conductivity type in a direction substantially perpendicular to the bottom of the trench.
17. A manufacturing method of a semiconductor device comprising:
forming a trench in a first semiconductor layer of a first conductivity type;
forming an epitaxially grown second semiconductor layer of the first conductivity type on a side wall of the trench;
forming an epitaxially grown third semiconductor layer of a second conductivity type on the second semiconductor layer formed on the side wall of the trench;
forming an epitaxially grown fourth semiconductor layer of the first conductivity type on the third semiconductor layer formed on the side wall of the trench;
forming a base layer of the second conductivity type in an upper part of the third semiconductor layer;
forming a region of the first conductivity type on a surface of the base layer selectively;
forming a gate insulating film on the base layer; and
forming a gate electrode on the gate insulating film.
18. The manufacturing method of a semiconductor device according to claim 17, wherein the forming an epitaxially grown second semiconductor layer includes epitaxially growing the second semiconductor layer on the side wall and the bottom of the trench, and removing part of the second semiconductor layer grown on the bottom of the trench.
19. The manufacturing method of a semiconductor device according to claim 17, wherein the forming an epitaxially grown third semiconductor layer includes epitaxially growing the third semiconductor layer on the side wall and the bottom of the trench, and removing part of the third semiconductor layer grown on the bottom of the trench.
20. The manufacturing method of a semiconductor device according to claim 17, further comprising removing the second through fourth semiconductor layers formed outside the trench, before forming the base layer.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A fabric dewatering apparatus for use after a fabric cleaning apparatus in a paper machine comprising:
at least one endless wicking substrate disposed for rotation about a dryer roll;
the endless wicking substrate and the fabric brought into surface contact as the fabric traverses at least a portion of the dryer roll’s circumference; and
a wicking substrate dewatering apparatus disposed along the wicking substrate’s travel path after the dryer roll.
2. The fabric dewatering apparatus of claim 1 wherein the endless wicking substrate is a felt.
3. The fabric dewatering apparatus of claim 2 wherein the wicking substrate dewatering apparatus comprises a felt pressure roll nipped with a felt vacuum roll, and the felt is disposed in the pressure roll nip between the felt pressure roll and the felt vacuum roll.
4. The fabric dewatering apparatus of claim l wherein the endless wicking substrate is a capillary membrane.
5. The fabric dewatering apparatus of claim 1 comprising an air knife located adjacent to the fabric.
6. The fabric dewatering apparatus of claim 5 wherein the air knife is disposed after the fabric dewatering apparatus relative to the fabric’s travel path.
7. The fabric dewatering apparatus of claim 1 comprising a fabric pressure roll nipped with the drying roll, and the fabric is disposed in a fabric nip between the fabric pressure roll and the dryer roll.
8. The fabric dewatering apparatus of claim 1 wherein the fabric wraps the dryer roll and the wrap angle is between about 10 degrees to about 270 degrees.
9. The fabric dewatering apparatus of claim 1 wherein the paper machine comprises a through air dryer and a dryer fabric wrapping a portion of the through air dryer, and the fabric dewatering apparatus dewaters the dryer fabric after being cleaned by at least one cleaning shower disposed after the through air dryer relative to the dryer fabric’s travel path.
10. The fabric dewatering apparatus of claim 9 wherein the dryer fabric also wraps at least a portion of a pressure roll nipped against a Yankee dryer; and the at least one cleaning shower and the fabric dewatering apparatus are disposed after the pressure roll relative to the dryer fabric’s travel path.
11. The fabric dewatering apparatus of claim 1 wherein greater than about 15 gsm of the showering water is removed from the fabric.
12. The fabric dewatering apparatus of claim 1 wherein at least 15 percent of the showering water is removed from the fabric.
13. The apparatus of claim 1 wherein the felt contacts the surface of the drying roll.
14. The apparatus of claim 1 wherein the fabric contacts the surface of the drying roll.
15. A fabric dewatering apparatus for use after a fabric cleaning apparatus in a paper machine comprising:
an endless first wicking substrate wrapped about a first dryer roll;
an endless second wicking substrate wrapped about a second dryer roll, said second dryer roll forming a nip with the first dryer roll such that the first and second wicking substrates are positioned within the nip;
a fabric disposed in the nip between the two wicking substrates; and
a wicking substrate dewatering apparatus disposed along the wicking substrates’travel path after the dryer rolls.
16. The fabric dewatering apparatus of claim 15 wherein both endless wicking substrates comprise felts, and the both felts are dewatered by a felt pressure roll nipped with a felt vacuum roll.
17. The fabric dewatering apparatus of claim 15 wherein the fabric traverses an S-wrap about the two nipped dryer rolls.
18. The fabric dewatering apparatus of claim 15 wherein the endless wicking substrates are capillary membranes.
19. The fabric dewatering apparatus of claim 15 comprising an air knife located adjacent to the fabric.
20. The fabric dewatering apparatus of claim 19 wherein the air knife is disposed after the fabric dewatering apparatus relative to the fabric’s travel path.
21. The fabric dewatering apparatus of claim 15 wherein the paper machine comprises a through air dryer and a dryer fabric wrapping a portion of the through air dryer, and the fabric dewatering apparatus dewaters the dryer fabric after being cleaned by at least one cleaning shower disposed after the through air dryer relative to the dryer fabric’s travel path.
22. The fabric dewatering apparatus of claim 21 wherein the dryer fabric also wraps at least a portion of a pressure roll nipped against a Yankee dryer; and the at least one cleaning shower and the fabric dewatering apparatus are disposed after the pressure roll relative to the dryer fabric’s travel path.
23. The fabric dewatering apparatus of claim 15 wherein greater than about 15 gsm of the showering water is removed from the fabric.
24. The fabric dewatering apparatus of claim 15 wherein at least 15 percent of the showering water is removed from the fabric.