Silicon nitride on silicon oxide coatings for semiconductor devices

Claim 1

A METHOD OF MAKING A SEMICONDUCTOR DEVICE COMPRISING THE STEPS OF: A. PREPARING A SEMICONDUCTOR SUBSTRATE COMPRISING A PRINCIPAL SURFACE HAVING A PREDETERMINED PORTION THEREOF COVERED WITH A FIRST INSULATING FILM CONSISTING MAINLY OF SILICON OXIDE, B. COVERING AT LAST A PORTION OF THE EXPOSED SURFACE OF SAID FIRST FILM AND AT LAST A PORTION OF SAID PRINCIPAL SURFACE NOT COVERED WITH THE FIRST FILM WITH A SECOND INSULATING FILM CONSISTING MAINLY OF SILICON NITRIDE, C. COMPLETELY COVERING SAID FIRST AND SECOND FILMS, EXCEPT FOR A PORTION OF SAID SECOND FILM DIRECTLY CONTACTING THE SURFACE OF SAID SEMICONDUCTOR SUBSTRATE AT A LOCATION SPACED FROM THE PORTION OF SAID SURFACE COVERED WITH SAID FIRST INSULATING FILM, WITH A CORROSION RESISTIVE MASK, D. EXPOSING THE COMBINATION THUS COMPOSED TO AN ETCHANT TO PARTIALLY ETCH AWAY THE PORTION OF SAID SECOND INSULATING FILM NOT COVERED WITH SAID CORROSION RESISTIVE MASK, AND E. INTRODUCING ACONDUCTIVITY TYPE IMPURITY INTO SAID SUBSTRATE USING SAID FIRST INSULATING FILM AS A SELECTIVE MASK.

Claim 2

A METHOD OF MAKING A SEMICONDUCTOR DEVICE COMPRISING THE STEPS OF: A. PREPARING A SEMICONDUCTOR SUBSTRATE COMPRISING A PRINCIPAL SURFACE HAVING A PREDETERMINED PORTION THEREOF COVERED WITH A FIRST INSULATING FILM CONSISTING MAINLY OF SILICON OXIDE, B. COVERING AT LAST A PORTION OF THE EXPOSED SURFACE OF SAID FIRST FILM AND AT LAST A PORTION OF SAID PRINCIPAL SURFACE NOT COVERED WITH THE FIRST FILM WITH A SECOND INSULATING FILM CONSISTING MAINLY OF SILICON NITRIDE, C. COMPLETELY COVERING SAID FIRST AND SECOND FILMS, EXCEPT FOR A PORTION OF SAID SECOND FILM DIRECTLY CONTACTING THE SURFACE OF SAID SEMICONDUCTOR SUBSTRATE AT A LOCATION SPACED FROM THE PORTION OF SAID SURFACE COVERED WITH SAID FIRST INSULATING FILM, WITH A CORROSION RESISTIVE MASK, D. EXPOSING THE COMBINATION THUS COMPOSED TO AN ETCHANT TO PARTIALLY ETCH AWAY THE PORTION OF SAID SECOND INSULATING FILM NOT COVERED WITH SAID CORROSION RESISTIVE MASK, AND E. INTRODUCING ACONDUCTIVITY TYPE IMPURITY INTO SAID SUBSTRATE USING SAID FIRST INSULATING FILM AS A SELECTIVE MASK.

Claim 3

A method for manufacturing a semiconductor device, comprising the steps of: covering a major surface of a semiconductor substrate with a first oxide film having a hole extending to the major surface; introducing a conductivity type determining impurity into said substrate through said hole to form a diffused region defining with the adjacent semiconductor material a PN junction terminating at the portion of said major surface covered with said first oxide film; forming a second oxide film to cover said diffused region in said hole; removing a portion of said first oxide film and at least a portion of said second oxide film so that the exposed major surface of said semiconductor substrate completely surrounds the remaining portion of the first oxide film which covers the entire edge portion of said PN junction and so that a portion of said diffused region is exposed; depositing an insulating film consisting substantially of silicon nitride on said semiconductor substrate to completely cover the exposed surfaces of said oxide films, the exposed surface of said diffused region and the exposed portion of said major surface surrounding said first oxide film, thereby entirely shielding the remaining oxide films from the surrounding atmosphere; forming in said insulating film an opening extending to said diffused region; and connecting an electrode to said diffused region through said opening.

Claim 4

A method for manufacturing a semiconductor device, comprising the steps of: covering a major surface of a semiconductor substrate with a first oxide film having a hole extending to the major surface; introducing a conductivity type determining impurity into said substrate through said hole to form a diffused region defining with the adjacent semiconductor material a PN junction terminating at the portion of said major surface covered with said first oxide film; forming a second oxide film to cover said diffused region in said hole; removing a portion of said first oxide film and at least a portion of said second oxide film so that the exposed major surface of said semiconductor substrate completely surrounds the remaining portion of the first oxide film which covers the entire edge portion of said PN junction and so that a portion of said diffused region is exposed; depositing an insulating film consisting substantially of silicon nitride on said semiconductor substrate to completely cover the exposed surfaces of said oxide films, the exposed surface of said diffused region and the exposed portion of said major surface surrounding said first oxide film, thereby entirely shielding the remaining oxide films from the surrounding atmosphere; forming in said insulating film an opening extending to said diffused region; and connecting an electrode to said diffused region through said opening.

Claim 5

A method for manufacturing semiconductor devices, comprising the steps of: preparing a semiconductor substrate including a plurality of semiconductor regions formed in a major surface of said substrate, each of said plurality of semiconductor regions defining with the adjacent semiconductor material a PN junction terminating at the major surface of said substrate; forming an oxide film on said major surface of said semiconductor substrate to completely cover the exposed edge portions of said PN junctions; removing selected portions of said oxide film to expose each of said plurality of semiconductor regions and a circumferential portion of the major surface completely surrounding a portion of said major surface in which said plurality of semiconductor regions are formed, the edge portions of said PN junctions completely covered with the remaining oxide film; covering with an insulating film consisting substantially of silicon nitride the exposed surfaces of said plurality of semiconductor regions, the exposed circumferential portion of said major surface and the entire exposed surface of the oxide film covering the portion of said major surface surrounded by said exposed circumferential portion of the major surface; forming a plurality of holes respectively extending to said semiconductor regions in the portions of said insulating film directly contacting the respective semiconductor regions; and connecting a contact to each respective semiconductor region through said plurality of holes.

Claim 6

A method for manufacturing semiconductor devices, comprising the steps of: preparing a semiconductor substrate including a plurality of semiconductor regions formed in a major surface of said substrate, each of said plurality of semiconductor regions defining with the adjacent semiconductor material a PN junction terminating at the major surface of said substrate; forming an oxide film on said major surface of said semiconductor substrate to completely cover the exposed edge portions of said PN junctions; removing selected portions of said oxide film to expose each of said plurality of semiconductor regions and a circumferential portion of the major surface completely surrounding a portion of said major surface in which said plurality of semiconductor regions are formed, the edge portions of said PN junctions completely covered with the remaining oxide film; covering with an insulating film consisting substantially of silicon nitride the exposed surfaces of said plurality of semiconductor regions, the exposed circumferential portion of said major surface and the entire exposed surface of the oxide film covering the portion of said major surface surrounded by said exposed circumferential portion of the major surface; forming a plurality of holes respectively extending to said semiconductor regions in the portions of said insulating film directly contacting the respective semiconductor regions; and connecting a contact to each respective semiconductor region through said plurality of holes.

Claim 7

A method for manufacturing semiconductor devices, comprising the steps of: forming a semiconductor wafer having a plurality of semiconductor portions spaced from each other and an oxide film covering a prinCipal surface of said semiconductor wafer, each of said semiconductor portions including at least one PN junction terminating at the principal surface of the wafer; forming holes respectively extending to said semiconductor portions and ditches exposing said principal surface so as to divide the oxide film into a plurality of islands, the islands of the oxide film being spaced from each other and covering said semiconductor portions, respectively; covering, with an insulating film consisting essentially of silicon nitride, the entire exposed surfaces of said semiconductor portions in said holes, the entire exposed portions of said principal surface in said ditches and the entire exposed surfaces of said oxide film; forming a plurality of further holes respectively extending to said semiconductor portions in the portions of said insulating film directly contacting with the respective semiconductor portions; connecting contacts to said semiconductor portions through said further holes, respectively; and dividing the semiconductor wafer at said ditches, in which said insulating film directly contacts the surface of the wafer, thereby forming separate semiconductor devices.

Claim 8

A method for manufacturing semiconductor devices, comprising the steps of: forming a semiconductor wafer having a plurality of semiconductor portions spaced from each other and an oxide film covering a prinCipal surface of said semiconductor wafer, each of said semiconductor portions including at least one PN junction terminating at the principal surface of the wafer; forming holes respectively extending to said semiconductor portions and ditches exposing said principal surface so as to divide the oxide film into a plurality of islands, the islands of the oxide film being spaced from each other and covering said semiconductor portions, respectively; covering, with an insulating film consisting essentially of silicon nitride, the entire exposed surfaces of said semiconductor portions in said holes, the entire exposed portions of said principal surface in said ditches and the entire exposed surfaces of said oxide film; forming a plurality of further holes respectively extending to said semiconductor portions in the portions of said insulating film directly contacting with the respective semiconductor portions; connecting contacts to said semiconductor portions through said further holes, respectively; and dividing the semiconductor wafer at said ditches, in which said insulating film directly contacts the surface of the wafer, thereby forming separate semiconductor devices.

Claim 12

A method of manufacturing a semiconductor device comprising the steps of: a. forming in a semiconductor substrate a semiconductor region of a conductivity type opposite to the substrate so as to define a PN junction terminating at a principal surface of the substrate, the termination of said PN junction and the vicinity thereof being covered with a first insulating film consisting essentially of silicon dioxide; b. forming a hole in the first insulating film so as to expose a surface portion of said semiconductor region; c. covering the entire upper surface of said first insulating film, the entire side walls of said hole and the exposed surface portion of said semiconductor region with a second insulating film consisting essentially of silicon nitride; d. completely covering said second insulating film with a corrosion resistive mask; e. selectively removing a portion of said second insulating film covering said semiconductor region so as to again expose a surface portion of said semiconductor region but not to expose any portion of said first insulating film; and f. providing an electrode to said semiconductor region through said secondary exposed surface portion thereof.

Claim 13

A method of manufacturing a semiconductor device comprising the steps of: a. forming in a semiconductor substrate a semiconductor region of a conductivity type opposite to the substrate so as to define a PN junction terminating at a principal surface of the substrate, the termination of said PN junction and the vicinity thereof being covered with a first insulating film consisting essentially of silicon dioxide; b. forming a hole in the first insulating film so as to expose a surface portion of said semiconductor region; c. covering the entire upper surface of said first insulating film, the entire side walls of said hole and the exposed surface portion of said semiconductor region with a second insulating film consisting essentially of silicon nitride; d. completely covering said second insulating film with a corrosion resistive mask; e. selectively removing a portion of said second insulating film covering said semiconductor region so as to again expose a surface portion of said semiconductor region but not to expose any portion of said first insulating film; and f. providing an electrode to said semiconductor region through said secondary exposed surface portion thereof.

Claim 14

A method of manufacturing a semiconductor device comprising thE steps of: a. forming in a semiconductor substrate a semiconductor region of a conductivity type opposite to the substrate, so as to define a PN junction terminating at a principal surface of the substrate, the termination of said PN junction and the vicinity thereof being covered with a first insulating film consisting essentially of silicon dioxide; b. forming a hole in the first insulating film so as to expose a surface portion of said semiconductor region; c. covering the entire upper surface of said first insulating film, the entire side walls of said hole and the exposed surface portion of said semiconductor region with a second insulating film consisting essentially of silicon nitride; d. completely covering said insulating films, except for a portion of said second film directly contacting the surface of the semiconductor substrate at a location in said hole spaced from said first film, with a corrosion resistive mask; e. selectively removing a portion of said second insulating film which is not covered with said corrosion resistive mask, so as to expose the semiconductor surface in said hole; and f. providing an electrode to the exposed semiconductor surface in said hole.

Claim 15

A method of manufacturing a semiconductor device comprising thE steps of: a. forming in a semiconductor substrate a semiconductor region of a conductivity type opposite to the substrate, so as to define a PN junction terminating at a principal surface of the substrate, the termination of said PN junction and the vicinity thereof being covered with a first insulating film consisting essentially of silicon dioxide; b. forming a hole in the first insulating film so as to expose a surface portion of said semiconductor region; c. covering the entire upper surface of said first insulating film, the entire side walls of said hole and the exposed surface portion of said semiconductor region with a second insulating film consisting essentially of silicon nitride; d. completely covering said insulating films, except for a portion of said second film directly contacting the surface of the semiconductor substrate at a location in said hole spaced from said first film, with a corrosion resistive mask; e. selectively removing a portion of said second insulating film which is not covered with said corrosion resistive mask, so as to expose the semiconductor surface in said hole; and f. providing an electrode to the exposed semiconductor surface in said hole.