US4006040A — Semiconductor device manufacture

Claim 1

Independent Claim 309 words

An improved method for migrating a melt of metal-rich semiconductor material through a solid body of the semiconductor material including the process steps of: a. selecting a body of single crystal semiconductor material having two major opposed surfaces comprising the top and bottom surfaces thereof, a predetermined type conductivity, a predetermined level of resistivity, a preferred diamond cubic crystal structure, a preferred planar crystal orientation for at least one of the major surfaces, a vertical axis substantially perpendicular to the opposed major surfaces, and a first preferred crystal axis substantially parallel with the vertical axis and substantially perpendicular to the opposed major surfaces; b. vapor depositing a layer of metal on the major surface having a preferred planar crystal orientation, the layer having a preferred width and a preferred thickness and so oriented as to form at least one metal wire having a longitudinal axis substantially aligned parallel with a second preferred crystal axis of the crystal structure of the material of the body; c. heating the body and the layer of metal to an elevated temperature for a predetermined period of time sufficient to sinter at least a portion of the layer of metal to a portion of the semiconductor material of the major surface of the body; d. heating the sintered body and the metal wire to a predetermined elevated temperature sufficient to form a melt of metal-rich semiconductor material on the surface of the body; e. establishing a temperature gradient substantially parallel to the vertical axis of the body and the first axis of the crystal structure; and f. migrating the melt of metal-rich semiconductor material through the solid body, substantially aligned with the first axis of the crystal structure, to a predetermined depth beneath that major surface to form a planar region of recrystallized material of the body having solid solubility of the metal therein.

Claim 2

Dependent Claim 309 words

An improved method for migrating a melt of metal-rich semiconductor material through a solid body of the semiconductor material including the process steps of: a. selecting a body of single crystal semiconductor material having two major opposed surfaces comprising the top and bottom surfaces thereof, a predetermined type conductivity, a predetermined level of resistivity, a preferred diamond cubic crystal structure, a preferred planar crystal orientation for at least one of the major surfaces, a vertical axis substantially perpendicular to the opposed major surfaces, and a first preferred crystal axis substantially parallel with the vertical axis and substantially perpendicular to the opposed major surfaces; b. vapor depositing a layer of metal on the major surface having a preferred planar crystal orientation, the layer having a preferred width and a preferred thickness and so oriented as to form at least one metal wire having a longitudinal axis substantially aligned parallel with a second preferred crystal axis of the crystal structure of the material of the body; c. heating the body and the layer of metal to an elevated temperature for a predetermined period of time sufficient to sinter at least a portion of the layer of metal to a portion of the semiconductor material of the major surface of the body; d. heating the sintered body and the metal wire to a predetermined elevated temperature sufficient to form a melt of metal-rich semiconductor material on the surface of the body; e. establishing a temperature gradient substantially parallel to the vertical axis of the body and the first axis of the crystal structure; and f. migrating the melt of metal-rich semiconductor material through the solid body, substantially aligned with the first axis of the crystal structure, to a predetermined depth beneath that major surface to form a planar region of recrystallized material of the body having solid solubility of the metal therein.

Claim 3

Dependent Claim 48 words

The method of claim 1 including the additional process step prior to depositing the layer of metal on the surface of the body of forming a mask on the major surface having a preferred planar crystal orientation to define a preferred geometrical configuration for the layer of metal.

Claim 4

Dependent Claim 23 words

The method of claim 2 wherein the preferred planar crystal orientation is one selected from the group consisting of (111), (100) and (110).

Claim 5

Dependent Claim 27 words

The method of claim 3 wherein the semiconductor material of the body is one selected from the group consisting of silicon, silicon carbide, germanium and gallium arsenide.

Claim 6

Dependent Claim 22 words

The method of claim 4 wherein the semiconductor material is silicon having N-type conductivity, and the metal of the wire is aluminum.

Claim 7

Dependent Claim 33 words

The method of claim 4 wherein the temperature gradient is from 50° C to 200° C per centimeter, and the migration is practiced at a temperature of from 700° C to 1350° C.

Claim 8

Dependent Claim 45 words

The method of claim 4 wherein the preferred planar crystal orientation is (100), the first preferred crystal axis is < 100 >, and the second preferred crystal axis is at least one selected from the group consisting of < 011 > and < 011 >.

Claim 9

Dependent Claim 23 words

The method of claim 4 wherein the preferred planar crystal orientation is (111), and the first preferred crystal axis is < 111 >.

Claim 10

Dependent Claim 43 words

The method of claim 3 including the additional process step after forming the mask and prior to depositing the layer of metal of: etching selectively the major surface of the body to form at least one trough-like depression therein of a predetermined depth.

Claim 11

Dependent Claim 27 words

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

Claim 12

Dependent Claim 22 words

The method of claim 10 wherein the semiconductor material is silicon having N-type conductivity, and the metal of the wire is aluminum.

Claim 13

Dependent Claim 33 words

The method of claim 10 wherein the temperature gradient is from 50° C to 200° C per centimeter, and the migration is practiced at a temperature of from 700° C to 1350° C.

Claim 14

Dependent Claim 45 words

The method of claim 10 wherein the preferred planar crystal orientation is (100), the first preferred crystal axis is < 100 >, and the second preferred crystal axis is at least one selected from the group consisting of < 011 > and < 011 >.

Claim 15

Dependent Claim 23 words

The method of claim 10 wherein the preferred planar crystal orientation is (111), and the first preferred crystal axis is < 111 >.

Claim 16

Dependent Claim 36 words

The method of claim 10 wherein the major surface has a preferred planar crystal orientation of (110); the first preferred crystal axis is < 110 >, and the second preferred crystal axis is < 110 >.

Claim 17

Dependent Claim 43 words

The method of claim 9 wherein the preferred planar crystal orientation is (111), and the geometrical configuration of the mask defines at least three lines, each line being oriented substantially parallel with a crystal axis which is substantially parallel with the (111) plane.

Claim 18

Dependent Claim 27 words

The method of claim 16 wherein the semiconductor material of the body is one selected from the group consisting of silicon, silicon carbide, germanium and gallium arsenide.

Claim 19

Dependent Claim 22 words

The method of claim 17 wherein the semiconductor material is silicon having N-type conductivity, and the metal of the wire is aluminum.

Claim 20

Dependent Claim 12 words

The method of claim 16 wherein the geometrical configuration defines a hexagon.

Claim 21

Dependent Claim 92 words

The method of claim 19 including the additional process step of forming a planar region having two opposed major surfaces in the body and so oriented that the two opposed major surfaces are substantially parallel to the two major opposed surfaces of the body, one of the opposed major surfaces of the planar region being contiguous and coextensive with one of the major opposed surfaces of the body, and each melt is migrated a predetermined distance through the body to at least intersect the other major opposed surface of the planar region.

Claim 22

Dependent Claim 58 words

The method of claim 20 wherein each of the planar regions is of a second and opposite type conductivity than that of the body, and the intersecting planar regions divide the body into a plurality of regions of semiconductor material of the same type conductivity as that of the body and each is electrically isolated from one another.

Claim 23

Dependent Claim 30 words

The method of claim 21 wherein the semiconductor material is silicon of N-type conductivity, the planar regions are each of P-type conductivity, and the metal of the layer is aluminum.

Claim 24

Dependent Claim 48 words

The method of claim 3 wherein the preferred geometrical configuration defines at least two intersecting lines, one line being oriented substantially parallel with the first preferred crystal axis, and the second line being oriented substantially parallel with a third preferred crystal axis of the material of the body.

Claim 25

Dependent Claim 27 words

The method of claim 23 wherein the semiconductor material of the body is one selected from the group consisting of silicon, silicon carbide, germanium and gallium arsenide.

Claim 26

Dependent Claim 22 words

The method of claim 24 wherein the semiconductor material is silicon having N-type conductivity, and the metal of the wire is aluminum.

Claim 27

Dependent Claim 33 words

The method of claim 24 wherein the temperature gradient is from 50° C to 200° C per centimeter, and the migration is practiced at a temperature of from 700° C to 1350° C.

Claim 28

Dependent Claim 42 words

The method of claim 24 wherein the preferred planar crystal orientation is (100), the first preferred crystal axis is < 100 >, and the second preferred crystal axis is < 011 >, and the third preferred crystal axis is < 011 >.

Claim 29

Dependent Claim 54 words

The method of claim 24 wherein the preferred planar crystal orientation is (111), the first preferred crystal axis is < 111 >, the second preferred crystal axis is any crystal axis substantially parallel with the (111) plane, and the third preferred crystal axis is any remaining crystal axis substantially parallel with the (111) plane.

Claim 30

Dependent Claim 63 words

The method of claim 24 wherein the preferred planar crystal orientation is (111), the first preferred crystal axis is < 111 >, the second preferred crystal axis is one selected from the group consisting of < 011 >, < 101 > and < 110 >, and the third preferred crystal axis is any of the remaining axes substantially parallel with the (111) plane.

Claim 31

Dependent Claim 62 words

The method of claim 24 wherein the preferred crystal orientation is (111), the first preferred crystal axis is < 111 >, the second preferred crystal axis is one selected from the group consisting of < 112 >, < 211 > and < 121 >, and the third preferred crystal axis is any of the remaining axes substantially parallel with the (111) plane.

Claim 32

Dependent Claim 92 words

The method of claim 1 including the additional process step of forming a planar region having two opposed major surfaces in the body and so oriented that the two opposed major surfaces are substantially parallel to the two major opposed surfaces of the body; one of the opposed major surfaces of the planar region being contiguous and coextensive with one of the major opposed surfaces of the body, and each melt is migrated a predetermined distance through the body to at least intersect the other major opposed surface of the planar region.

Claim 33

Dependent Claim 58 words

The method of claim 31 wherein each of the planar regions is of a second and opposite type conductivity than that of the body, and the intersecting planar regions divide the body into a plurality of regions of semiconductor material of the same type conductivity as that of the body and each is electrically isolated from one another.

Claim 34

Dependent Claim 30 words

The method of claim 32 wherein the semiconductor material is silicon of N-type conductivity, the planar regions are each of P-type conductivity, and the metal of the layer is aluminum.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1980-02-01	1980-08-02	1981-02-01	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1984-02-01	1984-08-02	1985-02-01	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1988-02-01	1988-08-02	1989-02-01	$7700.00	Window Closed / Lapsed

Semiconductor device manufacture

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