Composite jfet-bipolar structure

Claim 2

A semiconductor device, comprising: (a) a semiconductor body portion of first type conductivity and having a major surface; (b) an annular first region of second type conductivity opposite said first type conductivity and extending from said major surface into said body portion; (c) a second region of said second type conductivity located within a region of said body portion circumscribed by said annular first region and extending to said major surface; (d) an annular third region of said second type conductivity extending between said first and second regions and extending from said major surface into said body portion a shallower distance than either of said first and second regions; (e) a zone of said first type conductivity within said second region and extending to said major surface; (f) means separated from said first and second regions, surrounding said second region and forming a semiconductor junction with a surface portion of said annular third region; and (g) contact means conductively connected separately to said body portion, said annular first region, said zone, and said semiconductor junction-forming means.

Claim 3

The invention according to claim 1, wherein the semiconductor junction of (f) is located closer to said annular first region than to said second region.

Claim 4

The invention according to claim 1 and further including a buried region in a lowermost part of said body portion spaced from said first and second regions and of higher conductivity relative thereto, said buried region having a lateral extent which at least substantially encompasses the distance between said second region and the contact means to said body portion.

Claim 5

The invention according to claim 1 wherein the contact means conductively connected to said body portion comprises a surface zone in said body portion of higher conductivity relative thereto, and a metal portion forming ohmic contact with said surface zone.

Claim 6

The invention according to claim 1 and further including means for applying operating potentials to said contact means whereby said annular first region operates as a source of a JFET, said body portion operates as a collector of a bipolar transistor and a bottom gate of said JFET, said zone operates as an emitter of said bipolar transistor, and said semiconductor junction-forming means operates as a top gate of said JFET.

Claim 7

A semiconductor device, comprising: (a) a semiconductor body portion of first type conductivity and having a major surface; (b) spaced apart source and drain regions of second type conductivity formed in said body portion and extending from said major surface a given depth within said body portion, an outer one of said regions surrounding an inner one of said regions; (c) a channel region of said second type conductivity extending the entire distance between said source and drain regions and extending from said major surface into said body portion a smaller distance than said given depth; (d) means forming an emitter zone of said first type conductivity within one of said source and drain regions, said one region constituting a base zone; (e) means spaced from said source, drain, and channel regions and forming a collector contact with a portion of the major surface of said semiconductor body portion; and (f) means spaced between said source and drain regions, surrounding the inner one of said regions and forming a semiconductor junction with a surface portion of said channel region so as to constitute a first gate region of a JFET including said source, drain, and channel regions as component parts thereof, with the means in (e) constituting a contact to another gate region of said JFET separate from said first gate region.

Claim 8

A semiconductor device, comprising: (a) a semiconductor body portion of first type conductivity and having a major surface; (b) spaced apart source and drain regions of second type conductivity formed in said body portion and extending from said major surface a given depth within said body portion, an outer one of said regions surrounding an inner one of said regions; (c) a channel region of said second type conductivity extending the entire distance between said source and drain regions and extending from said major surface into said body portion a smaller distance than said given depth; (d) means forming an emitter zone of said first type conductivity within one of said source and drain regions, said one region constituting a base zone; (e) means spaced from said source, drain, and channel regions and forming a collector contact with a portion of the major surface of said semiconductor body portion; and (f) means spaced between said source and drain regions, surrounding the inner one of said regions and forming a semiconductor junction with a surface portion of said channel region so as to constitute a first gate region of a JFET including said source, drain, and channel regions as component parts thereof, with the means in (e) constituting a contact to another gate region of said JFET separate from said first gate region.

Claim 9

The invention according to claim 6, wherein said semiconductor body portion has N type conductivity.

Claim 10

The invention according to claim 6 and further including isolation means surrounding said device.

Claim 11

The invention according to claim 6 wherein said source and drain regions and said emitter zone are formed by diffusion.

Claim 12

The invention according to claim 6 wherein said channel region and said gate region are formed by ion implantation.

Claim 13

The invention according to claim 1 wherein the means in (f) comprises a semiconductor region of first type conductivity forming a semiconductor junction with said annular third region.

Claim 14

The invention according to claim 1 wherein the means in (f) comprises a metal region forming a Schottky barrier junction with said annular third region.

Claim 15

The invention according to claim 6 wherein the means in (f) comprises a semiconductor region of first type conductivity forming a semiconductor junction with said channel region.

Claim 16

The invention according to claim 6 wherein the means in (f) comprises a metal region forming a Schottky barrier junction with said channel region.