Schottky or PN diode with composite sidewall

Claim 2

A diode disposed on an integrated circuit structure comprising: (a) a first electrically conductive region of doped semiconductor material of a first conductivity type; (b) a second electrically conductive region contacting said first region, said first and second regions exhibiting a diode barrier characteristic about the interface of said first and second regions, said second region including an upper surface and a peripheral boundary adjoining said upper surface; (c) a first insulative layer disposed over said first region and including an opening positioned about said second region, said insulative layer including a side surface portion along the periphery of the opening and a portion overlying portions of said first region, said side portion substantially aligned with the peripheral boundary of said second region; (d) an electrical contact to the upper surface of said second region; and (e) a sidewall insulative layer, physically distinct from said first insulative layer, preventing formation of a diode interface between said electrical contact and said first conductive region, said sidewall layer overlying and contacting the surface of said second region remote from said first electrically conductive region, said sidewall layer also abutting the side surface portion of said first insulative layer.

Claim 3

A diode formed on an integrated circuit structure comprising: (a) a first electrically conductive region formed of doped semiconductor material of a first conductivity type; (b) a second electrically conductive region contacting said first region, said first and second regions exhibiting a diode barrier characteristic about the interface of said first and second regions, said second region including an upper surface and a peripheral boundary adjoining the upper surface; (c) a first insulative layer formed over said first region and including an opening positioned about said second region, said insulative layer including a side surface portion along the periphery of the opening and a portion overlying portions of said first region, said side portion substantially aligned with the peripheral boundary of said second region; (d) an electrical contact to the upper surface of said second region; and (e) a sidewall insulative layer, distinct from said first insulative layer, for preventing formation of a diode interface between said electrical contact and said first conductive region, said sidewall layer overlying and contacting the surface of said second region remote from said first electrically conductive region, said sidewall layer also abutting the side surface portion of said first insulative layer; wherein said second conductive region is a metal-containing Schottky barrier layer including a lower surface physically contacting the exposed portion of said semiconductor layer; and said electrical contact provides an anode connection.

Claim 4

A diode formed on an integrated circuit structure comprising: (a) a first electrically conductive region formed of doped semiconductor material of a first conductivity type; (b) a second electrically conductive region contacting said first region, said first and second regions exhibiting a diode barrier characteristic about the interface of said first and second regions, said second region including an upper surface and a peripheral boundary adjoining the upper surface; (c) a first insulative layer formed over said first region and including an opening positioned about said second region, said insulative layer including a side surface portion along the periphery of the opening and a portion overlying portions of said first region, said side portion substantially aligned with the peripheral boundary of said second region; (d) an electrical contact to the upper surface of said second region; and (e) a sidewall insulative layer, distinct from said first insulative layer, for preventing formation of a diode interface between said electrical contact and said first conductive region, said sidewall layer overlying and contacting the surface of said second region remote from said first electrically conductive region, said sidewall layer also abutting the side surface portion of said first insulative layer; wherein said second conductive region is a metal-containing Schottky barrier layer including a lower surface physically contacting the exposed portion of said semiconductor layer; and said electrical contact provides an anode connection.

Claim 5

The diode of claim 2 further comprising a cathode contact extending through a second opening in said first insulative layer to said first region.

Claim 6

The diode of claim 2 wherein said first insulative layer comprises chiefly silicon dioxide.

Claim 7

The diode of claim 2 wherein said sidewall insulative layer comprises chiefly silicon dioxide.

Claim 8

The diode of claim 2 wherein said sidewall insulative layer comprises chiefly silicon nitride.

Claim 9

The diode of claim 3 wherein said anode and cathode electrical contacts each comprise titanium tungsten.

Claim 10

The diode of claim 2 further comprising an aluminum conductor formed in electrical contact with said anode electrical contact.

Claim 11

The diode of claim 2 wherein said Schottky barrier layer is a silicide self-aligned to the opening in said first insulative layer.

Claim 12

The diode of claim 2 wherein the surface area of that portion of the lower surface of said Schottky barrier layer which physically contacts said first region is no greater than the surface area of said first conductive region opened through said first insulative layer.

Claim 13

The diode of claim 2 wherein the metal containing layer comprises platinum silicide.

Claim 14

The diode of claim 2 wherein the Schottky barrier layer is formed entirely within the opening in said first insulative layer.

Claim 15

The diode of claim 3 wherein said first region is of n-type conductivity.

Claim 16

The diode of claim 3 wherein said first insulative layer is a thermal silicon oxide and said sidewall insulative layer is a deposited silicon oxide.

Claim 17

The diode of claim 3 wherein said second conductive region comprises semiconductor material of a second conductivity type positioned between said first region and the opening in said first insulative layer.

Claim 18

The diode of claim 12 wherein said first region comprises a net n-dopant concentration.

Claim 19

The diode of claim 3 wherein said second conductive region comprises semiconductive material of a second conductivity type.

Claim 20

The diode of claim 17 wherein said second conductive region is characterized by ion implantation aligned with the opening in said first insulative layer.

Claim 21

The diode of claim 17 wherein said first insulative layer comprises chiefly silicon dioxide.

Claim 22

The diode of claim 18 wherein said sidewall insulative layer is deposited silicon dioxide.

Claim 23

The diode of claim 1 wherein said first insulative layer and said sidewall insulative layer are of the same chemical composition.

Claim 24

The diode of claim 21 wherein said first insulative layer and said sidewall insulative layer comprise silicon dioxide.

Claim 25

The diode of claim 1 wherein said first and second conductive regions are on a single semiconductor layer and characterized by opposite net dopant concentrations.

Claim 26

The diode of claim 1 wherein said first and second regions form a p-n junction diode, said first region self-aligned to the opening in said first insulative layer.

Claim 27

The diode of claim 17 wherein said second conductive region has a thickness of 3000 Angstroms or less.

Claim 28

A diode comprising: a heavily doped semiconductor layer of a first conductivity type; a semiconductor layer of the first conductivity type, lightly doped relative to said heavily doped layer, disposed over said heavily doped layer; a first insulative layer disposed over said lightly doped layer and having first and second openings to said lightly doped layer; a cathode semiconductor contact region formed in said lightly doped layer and aligned with said second opening; a silicide layer self-aligned with each said opening and contacting said lightly doped layer; and a sidewall insulative layer distinct from said first insulative layer, overlying said silicide layer in each said opening and aligned with peripheral portions of said first insulative layer along each said opening.

Claim 29

A diode comprising: a heavily doped semiconductor layer of a first conductivity type; a semiconductor layer of the first conductivity type, lightly doped relative to said heavily doped layer, disposed over said heavily doped layer; a first insulative layer disposed over said lightly doped layer and having first and second openings to said lightly doped layer; a cathode semiconductor contact region formed in said lightly doped layer and aligned with said second opening; a silicide layer self-aligned with each said opening and contacting said lightly doped layer; and a sidewall insulative layer distinct from said first insulative layer, overlying said silicide layer in each said opening and aligned with peripheral portions of said first insulative layer along each said opening.

Claim 30

The diode of claim 26 wherein the first insulative layer is a thermal oxide and the sidewall layer is a deposited oxide.

Claim 31

A p-n junction diode comprising: a heavily doped semiconductor layer of a first conductivity type; a semiconductor layer of the first conductivity type, lightly doped relative to said heavily doped layer, disposed over said heavily doped layer; a first insulative layer disposed over said lightly doped layer and having first and second openings to said lightly doped layer; a cathode semiconductor contact region disposed in said lightly doped layer and aligned with said second opening; a region of a second conductivity type disposed in said lightly doped layer and in self-alignment about said first opening; and a sidewall insulative layer physically distinct from said first insulative layer, overlying both the region of said second conductivity type and said first insulative layer along each said opening, said sidewall layer self-aligned with said first opening.

Claim 32

A p-n junction diode comprising: a heavily doped semiconductor layer of a first conductivity type; a semiconductor layer of the first conductivity type, lightly doped relative to said heavily doped layer, disposed over said heavily doped layer; a first insulative layer disposed over said lightly doped layer and having first and second openings to said lightly doped layer; a cathode semiconductor contact region disposed in said lightly doped layer and aligned with said second opening; a region of a second conductivity type disposed in said lightly doped layer and in self-alignment about said first opening; and a sidewall insulative layer physically distinct from said first insulative layer, overlying both the region of said second conductivity type and said first insulative layer along each said opening, said sidewall layer self-aligned with said first opening.

Claim 33

The diode of claim 19 wherein said sidewall insulative layer comprises silicon nitride.