Method for reducing resistance for programmed antifuse

Claim 2

An improved semiconductor device comprising: antifuse film of the type composed of semiconductor material having a first electrical state which is characterized by high electrical resistivity and a second electrical state which is characterized by low electrical resistivity, said material being electrically and permanently configured to said second electrical state from said first electrical state upon application of a voltage exceeding a predetermined threshold voltage applied across at least a portion of said material, only that portion being subjected to said threshold voltage being configured from said first state to said second state, the remaining portion of said material, which is not exposed to said threshold voltage, remaining in said first state; and means for selectively decreasing the resistivity of said second electrical state of said portion of said material without decreasing the resistivity of said first electrical state before selective activation of said portion of said material to said second electrical state, wherein said means for selectively decreasing resistivity comprises deliberately added nonactivated conductive dopants dispersed within said material, said dopants characterized by having a nonactivated state wherein said dopants do not enhance the conduction of carriers in said film, said dopants further characterized by having an activated state wherein said dopants enhance the conduction of carriers in said film, said dopants being configured from said nonactivated state into said activated state upon application of a threshold voltage being applied across a predetermined and selected portion of said material in which said dopants are disposed.

Claim 3

The improved antifuse film of claim 1 wherein said dopants are ion implanted.

Claim 4

The improved antifuse film of claim 2 wherein said dopants are selected from the group consisting of boron, phosphorous, and arsenic.

Claim 5

An antifuse film comprising: semiconductor material having a first electrical state which is characterized by high electrical resistivity and a second electrical state which is characterized by low electrical resistivity, said material being electrically and permanently configured to said second electrical state from said first electrical state upon application of a voltage exceeding a predetermined threshold voltage applied across at least a portion of said material, only that portion being subjected to said threshold voltage being configured from said first state to said second state, the remaining portion of said material, which is not exposed to said threshold voltage, remaining in said first state; and deliverately added nonactivated conductive dopants dispersed within said semiconductor material, said dopants characterized by having a nonactivated state wherein said dopants do not enhance the conduction of carriers in said film, said dopants further characterized by having an activated state wherein said dopants do enhance the conduction of carriers in said film, said dopants being configured from said nonactivated state into said activated state upon application of said threshold voltage being applied across a predetermined and selected portion of said material in which said dopants are disposed.

Claim 6

An antifuse film comprising: semiconductor material having a first electrical state which is characterized by high electrical resistivity and a second electrical state which is characterized by low electrical resistivity, said material being electrically and permanently configured to said second electrical state from said first electrical state upon application of a voltage exceeding a predetermined threshold voltage applied across at least a portion of said material, only that portion being subjected to said threshold voltage being configured from said first state to said second state, the remaining portion of said material, which is not exposed to said threshold voltage, remaining in said first state; and deliverately added nonactivated conductive dopants dispersed within said semiconductor material, said dopants characterized by having a nonactivated state wherein said dopants do not enhance the conduction of carriers in said film, said dopants further characterized by having an activated state wherein said dopants do enhance the conduction of carriers in said film, said dopants being configured from said nonactivated state into said activated state upon application of said threshold voltage being applied across a predetermined and selected portion of said material in which said dopants are disposed.

Claim 9

The method of claim 5 wherein said step of implanting dopants comprises the step of ion implantation.

Claim 10

The method of claim 6 wherein said dopants are selected from the group consisting of boron, phosphorous and arsenic.

Claim 13

The method of claim 8 further comprising the step of applying said threshold voltage across said predetermined and selected portion of said material to ohmically heat said portion to a predetermined degree to activate said dopants.

Claim 14

The method of claim 8 wherein said step of implanting dopants comprises the step of ion implantation.

Claim 15

The method of claim 10 wherein said dopants are selected from the group consisting of boron, phosphorous and arsenic.

Claim 16

An improved electrical programmable read-only memory of the type having: a semiconductor substrate; a plurality of conductive word lines disposed on said substrate; an oxide layer of material disposed between said plurality of word lines and on said substrate; a plurality of antifuse films each disposed on one of said plurality of word lines in electrical contact with said word line, said antifuse film composed of semiconductor material having a first electrical state which is characterized by high electrical resistivity and a second electrical state which is characterized by low electrical resistivity, said material being electrically and permanently configured to said second electrical state from said first electrical state upon application of a voltage exceeding a predetermined threshold voltage applied across at least a portion of said material, only that portion being subjected to said threshold voltage being configured from said first state to said second state, the remaining portion of said material, which is not exposed to said threshold voltage, remaining in said first state; a plurality of conductive bit lines each disposed on one of said antifuse films and aligned at least with one of said word lines, wherein the improvement comprises: nonactivated conductive dopants deliberately implanted and dispersed within said antifuse film, said dopants characterized by having a nonactivated state wherein said dopants do not enhance the conduction of carriers in said film, said dopants further characterized by having an activated state wherein said dopants do enhance the conduction of carriers in said film, said dopants being configured from said nonactivated state into said activated state upon application of said threshold voltage being applied across a predetermined and selected portion of said material in which said dopants are disposed.

Claim 17

An improved electrical programmable read-only memory of the type having: a semiconductor substrate; a plurality of conductive word lines disposed on said substrate; an oxide layer of material disposed between said plurality of word lines and on said substrate; a plurality of antifuse films each disposed on one of said plurality of word lines in electrical contact with said word line, said antifuse film composed of semiconductor material having a first electrical state which is characterized by high electrical resistivity and a second electrical state which is characterized by low electrical resistivity, said material being electrically and permanently configured to said second electrical state from said first electrical state upon application of a voltage exceeding a predetermined threshold voltage applied across at least a portion of said material, only that portion being subjected to said threshold voltage being configured from said first state to said second state, the remaining portion of said material, which is not exposed to said threshold voltage, remaining in said first state; a plurality of conductive bit lines each disposed on one of said antifuse films and aligned at least with one of said word lines, wherein the improvement comprises: nonactivated conductive dopants deliberately implanted and dispersed within said antifuse film, said dopants characterized by having a nonactivated state wherein said dopants do not enhance the conduction of carriers in said film, said dopants further characterized by having an activated state wherein said dopants do enhance the conduction of carriers in said film, said dopants being configured from said nonactivated state into said activated state upon application of said threshold voltage being applied across a predetermined and selected portion of said material in which said dopants are disposed.

Claim 18

The improved read-only memory of claim 12 wherein said dopants are selected from the group consisting of boron, phosphorous and arsenic.

Claim 19

An improved semiconductor device comprising: antifuse film of the type composed of semiconductor material having a first electrical state which is characterized by high electrical resistivity and a second electrical state which is characterized by low electrical resistivity, said material being electrically and permanently configured to said second electrical state from said first electrical state upon application of a voltage exceeding a predetermined threshold voltage applied across at least a portion of said material, only that portion being subjected to said threshold voltage being configured from said first state to said second state, the remaining portion of said material, which is not exposed to said threshold voltage, remaining in said first state; and means for balancing forward and reverse programming voltage across said antifuse film comprising ion implanted dopants dispersed within a shallow upper interface portion of said material, conductivity type and dosage of said dopants being selected so that forward and reverse programming voltages are substantially balanced.

Claim 20

An improved semiconductor device comprising: antifuse film of the type composed of semiconductor material having a first electrical state which is characterized by high electrical resistivity and a second electrical state which is characterized by low electrical resistivity, said material being electrically and permanently configured to said second electrical state from said first electrical state upon application of a voltage exceeding a predetermined threshold voltage applied across at least a portion of said material, only that portion being subjected to said threshold voltage being configured from said first state to said second state, the remaining portion of said material, which is not exposed to said threshold voltage, remaining in said first state; and means for balancing forward and reverse programming voltage across said antifuse film comprising ion implanted dopants dispersed within a shallow upper interface portion of said material, conductivity type and dosage of said dopants being selected so that forward and reverse programming voltages are substantially balanced.

Claim 21

The device of claim 14 further comprising: means for selectively decreasing the resistivity of said second electrical state of said portion of said material.

Claim 22

The device of claim 1 wherein said means for means for balancing forward and reverse programming voltage across said antifuse film comprises ion implanted dopants dispersed within a shallow upper interface portion of said material, conductivity type and dosage of said dopants being selected so that forward and reverse programming voltages are substantially balanced.

Claim 23

An improvement in a method of balancing forward and reverse programming voltages across a semiconductor material, said material having a first electrical state which is characterized by high electrical resistivity and said second electrical state being characterized by low electrical resistivity, said material being electrically and permanently configured to said second electrical state from said first electrical state upon application of a voltage exceeding a predetermined threshold voltage applied across at least a portion of said material, only that portion being subject to said threshold voltage being configured from said first state to said second state, the remaining portion of said material, which is not exposed to said threshold voltage, remaining in said first state, said improvement comprising the step of: shallowly ion implanting dopants into an upper interface portion of said material to form a high dopant gradient to produce an electric field in said interface portion, said dopants characterized by a conductivity type and dopant gradient so that of forward and reverse programming threshold voltages of said semiconductor material are alterable, including being set substantially equal absolute magnitudes, regardless of direction of voltage across said material.

Claim 24

An improvement in a method of balancing forward and reverse programming voltages across a semiconductor material, said material having a first electrical state which is characterized by high electrical resistivity and said second electrical state being characterized by low electrical resistivity, said material being electrically and permanently configured to said second electrical state from said first electrical state upon application of a voltage exceeding a predetermined threshold voltage applied across at least a portion of said material, only that portion being subject to said threshold voltage being configured from said first state to said second state, the remaining portion of said material, which is not exposed to said threshold voltage, remaining in said first state, said improvement comprising the step of: shallowly ion implanting dopants into an upper interface portion of said material to form a high dopant gradient to produce an electric field in said interface portion, said dopants characterized by a conductivity type and dopant gradient so that of forward and reverse programming threshold voltages of said semiconductor material are alterable, including being set substantially equal absolute magnitudes, regardless of direction of voltage across said material.

Claim 25

The improvement of claim 17 further comprising the steps of: implanting nonactivated conductive dopants into said material, said dopants characterized by having a nonactivated state wherein said dopants do not enhance the conduction of carriers in said film, said dopants further characterized by having an activated state wherein said dopants do enhance the conduction of carriers in said film, said dopants being configured from said nonactivated state into said activated state upon application of said threshold voltage being applied across a predetermined and selected portion of said material in which said dopants are disposed; and applying said threshold voltage across said predetermined and selected portion of said material to activate a corresponding selected portion of said dopants implanted into said material.