Deep diode bilateral semiconductor switch

Claim 2

In a bilateral semiconductor switch comprising a lamellar body of single crystal semiconductor material having two opposed major surfaces and embodying at least five regions of alternate and opposite type conductivity, a P-N junction formed by the contiguous surfaces of each pair of regions of opposite type conductivity, at least two regions of opposite type conductivity having coextensive surfaces comprising one of the two opposed major surfaces and the P-N junction formed therebetween having at least one end portion terminating in the major surface and another portion thereof disposed substantially parallel to the two major opposed surfaces, at least two other regions of opposite type conductivity having coextensive surfaces comprising the other of the major surfaces and the P-N junction formed therebetween having at least one end portion terminating in the other of the major surfaces and another portion thereof disposed substantially parallel to the two major opposed surfaces, a first electrical contact affixed to one major surface and in ohmic electrical contact with the at least two regions of opposite type conductivity and the end portion of the P-N junction exposed therein and a second electrical contact affixed to the other major surface and in ohmic electrical contact with the other at least two regions of opposite type conductivity and the end portion of the junction exposed therein, the improvement consisting of: the body has a preferred crystallographic structure; a side surface of the body has a preferred planar crystal orientation which is one selected from the group consisting of (100), (110) and (111); at least one of the regions consists of recrystallized semiconductor material of the body formed in situ by the thermal migration of a melt of a metal-rich semiconductor material of the body by thermal gradient zone melting at a predetermined elevated temperature along a thermal gradient substantially parallel with a first preferred crystal axis of the material of the body and the region and has a predetermined level of concentration of the metal of the melt as determined by the solid solubility limit of that metal in that semiconductor material at that predetermined elevated temperature of migration and the metal is distributed substantially uniformly throughout the entire region; the metal including at least one dopant impurity material to impart a predetermined type conductivity and a predetermined level of resistivity to the at least one region; the at least one region is oriented substantially parallel with a second preferred crystal axis, and the at least one region of recrystallized semiconductor material having a substantially constant level of resistivity throughout the region.

Claim 3

The semiconductor device of claim 1 wherein the semiconductor material is one selected from the group consisting of silicon, silicon carbide, gallium arsenide and germanium.

Claim 4

The semiconductor device of claim 2 wherein the semiconductor material is silicon, and the dopant metal is aluminum.

Claim 5

The semiconductor device of claim 1 including at least one additional pair of abutting regions of opposite type conductivity and a P-N junction formed therebetween disposed between the first and second regions and the fourth and fifth regions of opposite type conductivity to provide a device having at least seven integral abutting regions of alternate and opposite type conductivity.

Claim 6

The bilateral semiconductor switch of claim 1 wherein the first, third and fifth regions are of a first type conductivity, the material of the second and fourth regions each region is formed in situ by thermal gradient zone melting and consists of recrystallized semiconductor material of the body and the dopant material therein imparts a second type conductivity thereto.

Claim 7

The semiconductor device of claim 5 wherein the semiconductor material is one selected from the group consisting of silicon, silicon carbide, gallium arsenide and germanium.

Claim 8

The semiconductor device of claim 6 wherein the semiconductor material is silicon, and the dopant impurity material is aluminum.

Claim 9

The semiconductor device of claim 5 including at least one additional pair of abutting regions of opposite type conductivity and a P-N junction formed therebetween disposed between the third region and the fourth and fifth regions of opposite type conductivity and in abutting contact therewith to provide a device having at least seven integral abutting regions of alternate and opposite type conductivity.

Claim 10

The bilateral semiconductor switch of claim 5 wherein the first region is oriented with respect to the second region so as to encompass a portion thereof that embodies that portion of the second region having the surface coextensive with the surface of the first region to comprise a major surface of the body, and including a sixth region of first type conductivity disposed in the fourth region and spaced from the fifth region, the sixth region having a surface coextensive with the surfaces of the fourth and fifth regions comprising the other of the major surfaces; a P-N junction formed by the contiguous abutting surfaces of the material of the fourth and sixth regions of opposite type conductivity, the junction having at least one end portion terminating in the other of the major surfaces and another portion substantially parallel to the two opposed major surfaces, and a third electrical contact affixed to the other of the major surfaces spaced from the second electrical contact, and in an ohmic electrical contact with the fourth and sixth regions and the end portion of the P-N junction exposed thereat.

Claim 11

The semiconductor device of claim 9 wherein the semiconductor material is one selected from the group consisting of silicon, silicon carbide, gallium arsenide and germanium.

Claim 12

The semiconductor device of claim 10 wherein the semiconductor material is silicon, and the dopant impurity material is aluminum.

Claim 13

The semiconductor device of claim 9 including at least one additional pair of abutting regions of opposite type conductivity and a P-N junction formed therebetween disposed between the third region and the fourth and fifth regions of opposite type conductivity and in an abutting contact relationship therewith to provide a device having at least seven integral abutting regions of alternate and opposite type conductivity.

Claim 14

The bilateral semiconductor switch of claim 1 wherein the preferred planar orientation of the side surface is (100), the first preferred crystal axis is <100>, and the second preferred axis is one selected from the group consisting of <011> and <011>.

Claim 15

The bilateral semiconductor switch of claim 1 wherein the preferred planar orientation of the side surface is (110), the first preferred crystal axis is <110>, and the second preferred crystal axis is <110>.

Claim 16

The bilateral semiconductor switch of claim 1 wherein the preferred planar orientation of the side surface is (111), and the first preferred crystal axis is <111>.

Claim 17

The bilateral semiconductor switch of claim 15 wherein the second preferred crystal axis is one selected from the group consisting of <112>, <211>, <121>, <011>, <101> and <110>.

Claim 18

A bilateral semiconductor switch comprising a body of single crystal semiconductor material having a first type conductivity, a predetermined level of resistivity and two major opposed surfaces, at least one of which has a preferred planar crystal orientation which is one selected from the group consisting of (100), (110) and (111); a first column-like region disposed in the body substantially perpendicular to the surface of preferred planar crystal orientation and extending between and terminating in the two opposed major surfaces and the first region consisting of recrystallized semiconductor material of the body formed in situ in the body by the migration of a melt of metal-rich semiconductor material of the body by thermal gradient zone melting at a predetermined elevated temperature along a thermal gradient substantially parallel with a first preferred crystal axis of the region and has a predetermined level of concentration of the metal of the melt as determined by the solid solubility limit of that metal in that semiconductor material at that predetermined elevated temperature of migration and the metal is distributed substantially uniformly throughout the entire region, the metal including at least one dopant impurity material to impart a predetermined level of resistivity and a predetermined type conductivity to the region so formed; four concentric abutting regions of alternate first and second type conductivity and a selected level of resistivity, each having a rectangular-like planar configuration encompassing, and in abutting contact relationship with each other and the first region, each of the four regions extending substantially perpendicular to the surface of preferred planar orientation between, and terminating in, the two major opposed surfaces and having a vertical axis aligned substantially parallel with a first preferred crystal axis, each rectangular region consisting of two pair of planar regions, aligned substantially parallel with each other, each planar region of one pair being substantially perpendicular to, and integral with a planar region of the other pair, each region of one pair being aligned substantially parallel with a second preferred crystal axis the material of the body, and each region of the other pair being aligned substantially parallel with a third preferred axis of the material of the body; the second and fourth regions having a first type conductivity; the third and fifth regions having a second type conductivity; a P-N junction formed by the contiguous surfaces of each pair of abutting regions of opposite type conductivity and at least one end portion is exposed in the major surface of preferred planar orientation; a first ohmic electrical contact affixed simultaneously to a selected surface area of the first and second region and the exposed end portion of the P-N junction formed therebetween, and a second ohmic electrical contact affixed simultaneously to a selected surface area of the fourth and fifth regions and the exposed end portion of the P-N junction formed therebetween.

Claim 19

A bilateral semiconductor switch comprising a body of single crystal semiconductor material having a first type conductivity, a predetermined level of resistivity and two major opposed surfaces, at least one of which has a preferred planar crystal orientation which is one selected from the group consisting of (100), (110) and (111); a first column-like region disposed in the body substantially perpendicular to the surface of preferred planar crystal orientation and extending between and terminating in the two opposed major surfaces and the first region consisting of recrystallized semiconductor material of the body formed in situ in the body by the migration of a melt of metal-rich semiconductor material of the body by thermal gradient zone melting at a predetermined elevated temperature along a thermal gradient substantially parallel with a first preferred crystal axis of the region and has a predetermined level of concentration of the metal of the melt as determined by the solid solubility limit of that metal in that semiconductor material at that predetermined elevated temperature of migration and the metal is distributed substantially uniformly throughout the entire region, the metal including at least one dopant impurity material to impart a predetermined level of resistivity and a predetermined type conductivity to the region so formed; four concentric abutting regions of alternate first and second type conductivity and a selected level of resistivity, each having a rectangular-like planar configuration encompassing, and in abutting contact relationship with each other and the first region, each of the four regions extending substantially perpendicular to the surface of preferred planar orientation between, and terminating in, the two major opposed surfaces and having a vertical axis aligned substantially parallel with a first preferred crystal axis, each rectangular region consisting of two pair of planar regions, aligned substantially parallel with each other, each planar region of one pair being substantially perpendicular to, and integral with a planar region of the other pair, each region of one pair being aligned substantially parallel with a second preferred crystal axis the material of the body, and each region of the other pair being aligned substantially parallel with a third preferred axis of the material of the body; the second and fourth regions having a first type conductivity; the third and fifth regions having a second type conductivity; a P-N junction formed by the contiguous surfaces of each pair of abutting regions of opposite type conductivity and at least one end portion is exposed in the major surface of preferred planar orientation; a first ohmic electrical contact affixed simultaneously to a selected surface area of the first and second region and the exposed end portion of the P-N junction formed therebetween, and a second ohmic electrical contact affixed simultaneously to a selected surface area of the fourth and fifth regions and the exposed end portion of the P-N junction formed therebetween.

Claim 20

The bilateral semiconductor device of claim 17 wherein the material of each of the at least the third and fifth regions consists of recrystallized semiconductor material of the body having solid solubility of a dopant impurity material therein to impart the predetermined second type conductivity and predetermined level of resistivity thereto, the third and fifth regions each being formed in situ by thermal gradient zone melting in a manner similar to that of the first region.

Claim 21

The semiconductor device of claim 18 wherein semiconductor material is one selected from the group consisting of silicon, silicon carbide, gallium arsenide and germanium.

Claim 22

The semiconductor device of claim 19 wherein the semiconductor material is silicon, and the dopant impurity material is aluminum.

Claim 23

The bilateral semiconductor switch of claim 18 wherein the preferred planar orientation of the major surface is (100).

Claim 24

The semiconductor device of claim 21 wherein the semiconductor material is one selected from the group consisting of silicon, silicon carbide, gallium arsenide and germanium.

Claim 25

The semiconductor device of claim 22 wherein the semiconductor material is silicon, and the dopant impurity material is aluminum.

Claim 26

The bilateral semiconductor switch of claim 21 wherein the first preferred crystal axis is <100>, the second preferred crystal axis is <011>, and the third preferred crystal axis is <011>.

Claim 27

The bilateral semiconductor switch of claim 18 wherein the preferred planar crystal orientation is (111), and the first preferred crystal axis is <111>.

Claim 28

The bilateral semiconductor switch of claim 25 wherein the second preferred crystal axis is one selected from the group consisting of <011>, <101>, <110>, <112>, <211> and <121>, and the third preferred crystal axis is any crystal axis perpendicular to both the first and the second preferred crystal axes.