Pressure-sensitive schottky barrier semiconductor device having a substantially non-conductive barrier for preventing undesirable reverse-leakage currents and method for making the same

Claim 2

A pressure-sensitive semi-conductor device which comprises: a semi-conductor substrate of n-type conductivity having a recess formed in a specified region thereof; an insulating film covering a major surface portion of said semi-conductor substrate and having an opening therethrough exposing a major part of said recess, said opening being disposed above said recess, the cross-sectional area of said opening being less than the cross-sectional area of said recess, so as to provide a separation space in said semiconductor substrate, that extends around the portion of the recess located underneath the insulating film; a Schottky barrier formed at the bottom of said recess including a metal layer covering the opening in said insulating film and extending through said opening onto the bottom of said recess while leaving said separation space substantially vacant, said separation space extending to the base of said recess in said semiconductor substrate at the location where said Schottky barrier is formed, so that said Schottky barrier is surrounded by the separation space extending around the recess; and means for applying input pressure onto said metal layer.

Claim 3

The semi-conductor device of claim 1, wherein the width of said separation space is at least 1,000A.

Claim 4

The semi-conductor device of claim 1, wherein the semi-conductor substrate is of n-type silicon, the insulating film is of silicon dioxide, and the metal layer is of sputtered molybdenum.

Claim 5

The semi-conductor device of claim 1, wherein said means for applying the input pressure onto said metal layer includes a pressure needle imparting the input pressure onto the metal layer by way of its tip and simultaneously serving as a lead-out wire.

Claim 6

A pressure-sensitive semi-conductor device in which an insulating film covers a major surface portion of a semi-conductor substrate, in which an opening is provided in the insulating film to expose a defined area of the substrate, in which a Schottky barrier is formed in said defined area and includes a metal layer covering the area of the substrate exposed through the opening, and in which a means is adapted to be applied to the metal layer for the application of pressure, characterized by substantially non-conductive barrier means effectively preventing undesirable reverse-leakage currents caused by leakage to the metal layer of electric charges from an accumulation layer formed in parts of the semi-conductor substrate closely underneath the insulating film, said non-conductive barrier means comprising a recess formed in said substrate surrounding said metal layer beneath said opening, the cross-sectional area of said opening being less than the cross-sectional area of said recess, so as to provide a separation space in said substrate that extends around the portion of the recess located underneath said insulating film, said separation spaCe extending to the base of said recess in said semi-conductor substrate at the location where said Schottky barrier is formed, whereby said barrier means insulate said Schottky barrier from said electric charge accumulation layer.

Claim 7

A pressure-sensitive semi-conductor device in which an insulating film covers a major surface portion of a semi-conductor substrate, in which an opening is provided in the insulating film to expose a defined area of the substrate, in which a Schottky barrier is formed in said defined area and includes a metal layer covering the area of the substrate exposed through the opening, and in which a means is adapted to be applied to the metal layer for the application of pressure, characterized by substantially non-conductive barrier means effectively preventing undesirable reverse-leakage currents caused by leakage to the metal layer of electric charges from an accumulation layer formed in parts of the semi-conductor substrate closely underneath the insulating film, said non-conductive barrier means comprising a recess formed in said substrate surrounding said metal layer beneath said opening, the cross-sectional area of said opening being less than the cross-sectional area of said recess, so as to provide a separation space in said substrate that extends around the portion of the recess located underneath said insulating film, said separation spaCe extending to the base of said recess in said semi-conductor substrate at the location where said Schottky barrier is formed, whereby said barrier means insulate said Schottky barrier from said electric charge accumulation layer.

Claim 8

A pressure-sensitive Schottky type semi-conductor device which comprises: a semi-conductor substrate having a recess formed in a specified region of n-type conductivity; an insulating film covering a major surface portion of said semi-conductor substrate but exposing by its opening a major part of said recess with a side-etched separation space, that extends around the recess, being located underneath the insulating film; a metal layer covering said recess and the surrounding insulating film, which leaves said separation space substantially vacant; a Schottky barrier which is formed on a contact face between said metal layer and said recess and is surrounded by the separation space, said separation space extending to the base of said recess in said substrate beneath said opening at the location where said Schottky barrier is formed; and means for applying an input pressing force onto said metal layer.

Claim 9

A pressure-sensitive Schottky type semi-conductor device which comprises: a semi-conductor substrate having a recess formed in a specified region of n-type conductivity; an insulating film covering a major surface portion of said semi-conductor substrate but exposing by its opening a major part of said recess with a side-etched separation space, that extends around the recess, being located underneath the insulating film; a metal layer covering said recess and the surrounding insulating film, which leaves said separation space substantially vacant; a Schottky barrier which is formed on a contact face between said metal layer and said recess and is surrounded by the separation space, said separation space extending to the base of said recess in said substrate beneath said opening at the location where said Schottky barrier is formed; and means for applying an input pressing force onto said metal layer.

Claim 10

The pressure-sensitive semi-conductor device of claim 6, wherein the width of said separation space is at least 1,000 A.

Claim 11

The semi-conductor device of claim 6, wherein the semi-conductor substrate is of n-type silicon, the insulating film is of silicon dioxide, and the metal layer is of sputtered molybdenum.

Claim 12

The semi-conductor device of claim 6, wherein said means for applying the input pressure onto said metal layer includes a pressure needle imparting the input pressure onto the metal layer by way of its tip and simultaneously serving as a lead-out wire.

Claim 13

In a Schottky barrier type semi-conductor pressure sensitive device having a semi-conductor substrate, an insulating film covering a major surface portion of said substrate, an opening extending through said insulating film exposing a defined area of said substrate, a metal layer covering the area of said substrate exposed through said opening to form a Schottky barrier and means for transmitting applied pressure to said metal layer, the improvement comprising means for effectively preventing undesirable reverse leakage currents caused by leakage to said metal layer of electric charges from an accumulation layer formed in parts of said semi-conductor substrate closely beneath said insulating film, said means comprising a substantially non-conductive barrier guard space separating said metal layer from the electric charge accumulation layer said guard space comprising a recess formed in said substrate surrounding said metal layer beneath said opening, the cross-sectional area of said opening being less than the cross-sectional area of said recess, so as to provide a separation space in said substrate that extends around the portion of the recess located underneath said insulating film, said separation space extending to the base of said recess in said semi-conductor substrate at the location where said Schottky barrier is formed.

Claim 14

In a Schottky barrier type semi-conductor pressure sensitive device having a semi-conductor substrate, an insulating film covering a major surface portion of said substrate, an opening extending through said insulating film exposing a defined area of said substrate, a metal layer covering the area of said substrate exposed through said opening to form a Schottky barrier and means for transmitting applied pressure to said metal layer, the improvement comprising means for effectively preventing undesirable reverse leakage currents caused by leakage to said metal layer of electric charges from an accumulation layer formed in parts of said semi-conductor substrate closely beneath said insulating film, said means comprising a substantially non-conductive barrier guard space separating said metal layer from the electric charge accumulation layer said guard space comprising a recess formed in said substrate surrounding said metal layer beneath said opening, the cross-sectional area of said opening being less than the cross-sectional area of said recess, so as to provide a separation space in said substrate that extends around the portion of the recess located underneath said insulating film, said separation space extending to the base of said recess in said semi-conductor substrate at the location where said Schottky barrier is formed.

Claim 15

A pressure-sensitive semi-conductor device comprising: a semi-conductor substrate having a recess formed in one surface portion thereof; an insulating film formed on said one surface of said substrate within which said recess is formed, said insulating film overlapping a portion of said recess and having an opening therethrough, the cross-sectional area of which is less than the cross-sectional are a of said recess, forming a separation space in said semi-conductor substrate extending around the edges of the recess and located underneath the overlapping portion of said insulating film; a Schottky barrier formed at the bottom of said recess comprising a metal layer formed on said insulating film and extending through said opening onto the bottom of said recess so as to form said Schottky barrier between said metal layer and the bottom of said recess, the cross-sectioNal area of said metal layer which so extends onto the bottom of said recess having a cross-sectional area substantially the same as said opening; and means for applying pressure onto the portion of said metal layer directly above said Schottky barrier, whereby said separation space remains substantially vacant and said Schottky barrier is surrounded by said separation sapce formed in said recess, said separation space extending to the base of said semi-conductor substrate at the location where said Schottky barrier is formed, thereby insulating said metal layer from an electric charge accumulation layer in the portion of said substrate adjacent to said recess and underneath said insulating film, so as to ensure the sensitivity of said device to forces applied thereto.

Claim 16

A pressure-sensitive semi-conductor device comprising: a semi-conductor substrate having a recess formed in one surface portion thereof; an insulating film formed on said one surface of said substrate within which said recess is formed, said insulating film overlapping a portion of said recess and having an opening therethrough, the cross-sectional area of which is less than the cross-sectional are a of said recess, forming a separation space in said semi-conductor substrate extending around the edges of the recess and located underneath the overlapping portion of said insulating film; a Schottky barrier formed at the bottom of said recess comprising a metal layer formed on said insulating film and extending through said opening onto the bottom of said recess so as to form said Schottky barrier between said metal layer and the bottom of said recess, the cross-sectioNal area of said metal layer which so extends onto the bottom of said recess having a cross-sectional area substantially the same as said opening; and means for applying pressure onto the portion of said metal layer directly above said Schottky barrier, whereby said separation space remains substantially vacant and said Schottky barrier is surrounded by said separation sapce formed in said recess, said separation space extending to the base of said semi-conductor substrate at the location where said Schottky barrier is formed, thereby insulating said metal layer from an electric charge accumulation layer in the portion of said substrate adjacent to said recess and underneath said insulating film, so as to ensure the sensitivity of said device to forces applied thereto.

Claim 17

The semi-conductor device of claim 11, wherein said means for applying input pressure onto said metal layer includes a pressure needle imparting input pressure onto said metal layer by way of its tip and simultaneously serving as a lead-out wire.

Claim 18

A pressure-sensitive semi-conductor device comprising a semi-conductor device including three adjacent layers and two junctions therebetween and capable of transistor action, at least one of the outer layers of said three layers being a metal layer forming a metal-semi-conductor junction with the intermediate semi-conductor layer, and means for applying pressure to said metal-semi-conductor junction.

Claim 19

A pressure-sensitive semi-conductor device comprising a semi-conductor device including three adjacent layers and two junctions therebetween and capable of transistor action, at least one of the outer layers of said three layers being a metal layer forming a metal-semi-conductor junction with the intermediate semi-conductor layer, and means for applying pressure to said metal-semi-conductor junction.

Claim 20

A pressure sensitive semi-conductor device according to claim 13, wherein said metal-semi-conductor junction is formed along the wall of a recess formed in said intermediate semi-conductor layer and is provided with a closed space void of solid material at its periphery said space being surrounded by the wall of said recess, said metal layer and an insulating layer being provided the exposed surface of said intermediate semi-conductor layer.

Claim 21

A pressure sensitive semi-conductor device according to claim 14, wherein the depth of said recess is 3,000 A or more, the lateral extension of said space is 1,000 A or more, and the thickness of said metal layer is larger than the depth of said recess.