Bidirectional field emission devices, storage structures and fabrication methods

Claim 2

A bidirectional field emission device, comprising: a substrate having a surface; a first unitary field emission structure supported by said substrate having a first cathode portion of a first layer in parallel with said surface and a first anode portion; a second unitary field emission structure supported by said substrate having a second cathode portion of a second layer in parallel with said surface and a second anode portion; said first unitary field emission structure and said second unitary field emission structure being adjacently disposed with said first cathode portion over said second cathode portion in layered spaced relationship thereto, with said first cathode portion spaced from and opposing said second anode portion so as to enable electrons to flow by field emission from said first cathode portion of said first unitary field emission structure to said second anode portion of said second unitary field emission structure, and with said second cathode portion spaced from and opposing said first anode portion so as to enable electrons to flow by field emission from said second cathode portion of said second unitary field emission structure to said first anode portion of said first unitary field emission structure; and means for controlling the flow of electrons from said first cathode portion of said first unitary field emission structure and from said second cathode portion of said second unitary field emission structure.

Claim 3

The bidirectional field emission device of claim 1, wherein said first cathode portion includes a tip means for emitting electrons by field emission, said first cathode portion tip means being spaced a first distance y from said second anode portion of said second unitary field emission structure and wherein said second cathode portion includes a tip means for emitting electrons by field emission, said second cathode portion tip means being spaced a second distance y' from said first anode portion of said first unitary field emission structure.

Claim 4

The bidirectional field emission device of claim 2, wherein said first distance y and said second distance y' are substantially equal, y=y'.

Claim 5

The bidirectional field emission device of claim 2, wherein said control means includes: at least one control gate disposed adjacent said first cathode portion of said first unitary field emission structure and adjacent said second cathode portion of said second unitary field emission structure for controlling electron emissions therefrom; and means for applying respective electrical bias voltages to said first unitary field emission structure, said second unitary field emission structure and said at least one control gate.

Claim 6

The bidirectional field emission device of claim 4, wherein said at least one control gate includes a first gate member disposed adjacent the tip means of said first cathode portion of said first unitary field emission structure for controlling emission of electrons therefrom, said first gate member being spaced from said first cathode portion a first distance x, wherein x≦y≦10.(x), and a second gate member disposed adjacent the tip means of said second cathode portion of said second unitary field emission structure for controlling emission of electrons therefrom, said second gate member being spaced from said second cathode portion a second distance x', wherein x'≦y'≦10.(x').

Claim 7

The bidirectional field emission device of claim 5, wherein said first distance x and said second distance x' are substantially equal, x=x'.

Claim 8

The bidirectional field emission device of claim 2, wherein said control means includes a first gate member disposed adjacent the tip means of said first cathode portion of said first unitary field emission structure for controlling emission of electrons therefrom, and a second gate member disposed adjacent the tip means of said second cathode portion of said second unitary field emission structure for controlling emission of electrons therefrom.

Claim 9

The bidirectional field emission device of claim 7, wherein said first gate member and said first cathode portion tip means are self-aligned to terminate in a first common plane orthogonal to the upper surface of said substrate, and wherein said second gate member and said second cathode portion tip means are self-aligned to terminate in a second common plane orthogonal to the upper surface of said substrate.

Claim 10

The bidirectional field emission device of claim 8, wherein said first unitary field emission structure includes a contact pad electrically connecting said first cathode portion and said first anode portion thereof.

Claim 11

The bidirectional field emission device of claim 9, wherein said second cathode portion terminates at and electrically connects to said second anode portion of said second unitary field emission structure at said first common plane orthogonal to the upper surface of said substrate.

Claim 12

The bidirectional field emission device of claim 1, wherein said first cathode portion and said second cathode portion each have a thickness in a range of 50-1000 angstroms.

Claim 13

The bidirectional field emission device of claim 11, wherein said thickness is 150-250 angstroms.

Claim 14

The bidirectional field emission device of claim 1, wherein said parallel disposed first cathode portion and second cathode portion are spaced apart, said space between said first cathode portion and said second cathode portion comprising at least partially a chamber, said chamber containing a gas or a vacuum.

Claim 15

A field emission device storage cell for use in a DRAM device, said storage cell comprising: a first unitary field emission structure having a first cathode portion and a first anode portion; a second unitary field emission structure having a second cathode portion and a second anode portion; said first unitary field emission structure and said second unitary field emission structure being adjacently disposed with said first cathode portion spaced from and opposing said second anode portion so as to enable electrons to flow by field emission from said first cathode portion of said first unitary field emission structure to said second anode portion of said second unitary field emission structure, and with said second cathode portion spaced from and opposing said first anode portion so as to enable electrons to flow by field emission from said second cathode portion of said second unitary field emission structure to said first anode portion of said first unitary field emission structure; a charge image plane disposed adjacent and spaced parallel to said second anode portion of said second unitary field emission structure; a dielectric material disposed between said second anode portion and said charge image plane such that a charge storage capacitor is defined by said second anode portion, said dielectric material and said charge image plane; and means for controlling the flow of electrons from said first cathode portion of said first unitary field emission structure and from said second cathode portion of said second unitary field emission structure, thereby controlling writing of charge to or reading of charge from said charge storage capacitor.

Claim 16

A field emission device storage cell for use in a DRAM device, said storage cell comprising: a first unitary field emission structure having a first cathode portion and a first anode portion; a second unitary field emission structure having a second cathode portion and a second anode portion; said first unitary field emission structure and said second unitary field emission structure being adjacently disposed with said first cathode portion spaced from and opposing said second anode portion so as to enable electrons to flow by field emission from said first cathode portion of said first unitary field emission structure to said second anode portion of said second unitary field emission structure, and with said second cathode portion spaced from and opposing said first anode portion so as to enable electrons to flow by field emission from said second cathode portion of said second unitary field emission structure to said first anode portion of said first unitary field emission structure; a charge image plane disposed adjacent and spaced parallel to said second anode portion of said second unitary field emission structure; a dielectric material disposed between said second anode portion and said charge image plane such that a charge storage capacitor is defined by said second anode portion, said dielectric material and said charge image plane; and means for controlling the flow of electrons from said first cathode portion of said first unitary field emission structure and from said second cathode portion of said second unitary field emission structure, thereby controlling writing of charge to or reading of charge from said charge storage capacitor.

Claim 17

The field emission device storage cell of claim 14, wherein said first unitary field emission structure, said second unitary field emission structure, and said defined charge storage capacitor are disposed above an upper surface of a supporting substrate with said first cathode portion and said second cathode portion each extending parallel to the upper surface of said substrate, and wherein said first cathode portion and said second cathode portion each includes a tip means for emitting electrons by field emission.

Claim 18

The field emission device storage cell of claim 15, wherein said control means includes a first gate control disposed adjacent the tip means of said first cathode portion of said first unitary field emission structure for controlling emission of electrons therefrom, and a second gate control disposed adjacent the tip means of said second cathode portion of said second unitary field emission structure for controlling emission of electrons therefrom.

Claim 19

The field emission device storage cell of claim 16, wherein said first gate control and said first cathode portion tip means are self-aligned to terminate in a first common plane orthogonal to the upper surface of said substrate, and wherein said second gate control and said second cathode portion tip means are self-aligned to terminate in a second common plane orthogonal to the upper surface of said substrate.

Claim 20

The field emission device storage cell of claim 15, wherein said second anode portion, said dielectric material and said charge image plane are disposed within adjacent vertical trenches, each trench being substantially orthogonal to the upper surface of said supporting substrate.

Claim 21

The field emission device storage cell of claim 14, wherein said storage cell comprises a first storage cell, and wherein said first storage cell is further in combination with a second field emission device storage cell which comprises a mirror image of said first storage cell about the first anode portion of said first unitary field emission structure of said first storage cell such that first and second charge storage capacitors are defined and such that said first storage cell and said second storage cell share a common first unitary field emission structure.

Claim 22

A dual field emission storage device having dual charge storage capacitors for use in a DRAM device, said dual storage device comprising: a first unitary field emission structure having a first cathode portion, a first cathode portion, and a first anode portion; a second unitary field emission structure having a second cathode portion and a second anode portion; said first unitary field emission structure and said second unitary field emission structure being adjacently disposed with said first cathode portion spaced from and opposing said second anode portion so as to enable electrons to flow by field emission from said first cathode portion of said first unitary field emission structure to said second anode portion of said second unitary field emission structure, and with said second cathode portion spaced from and opposing said first anode portion so so as to enable electrons to flow by field emission from said second cathode portion of said second unitary field emission structure to said first anode portion of said first unitary field emission structure; a third unitary field emission structure having a third cathode portion and a third anode portion; said first unitary field emission structure and said third unitary field emission structure being adjacently disposed with said first cathode portion spaced from and opposing said third anode portion so as to enable electrons to flow by field emission from said first cathode portion of said first unitary field emission structure to said third anode portion of said third unitary field emission structure, and with said third cathode portion spaced from and opposing said first anode portion so as to enable electrons to flow by field emission from said third cathode portion of said third unitary field emission structure to said first anode portion of said first unitary field emission structure; a first charge image plane disposed adjacent and spaced parallel to said second anode portion of said second unitary field emission structure, and a second charge image plane disposed adjacent and spaced parallel to said third anode portion of said third unitary field emission structure; a first dielectric material disposed between said second anode portion and said first charge image plane whereby a first charge storage capacitor is defined by said second anode portion, said first dielectric material, and said first charge image plane, and a second dielectric material disposed between said third anode portion and said second charge image plane whereby a second charge storage capacitor is defined by said third anode portion, said second dielectric material, and said second charge image plane; and means for controlling the flow of electrons from said first cathode portion and said first cathode portion of said first unitary field emission structure, from said second cathode portion of said second unitary field emission structure, and from said third cathode portion of said third unitary field emission structure, thereby controlling writing of charge to or reading of charge from said first charge storage capacitor and said second charge storage capacitor.

Claim 23

A dual field emission storage device having dual charge storage capacitors for use in a DRAM device, said dual storage device comprising: a first unitary field emission structure having a first cathode portion, a first cathode portion, and a first anode portion; a second unitary field emission structure having a second cathode portion and a second anode portion; said first unitary field emission structure and said second unitary field emission structure being adjacently disposed with said first cathode portion spaced from and opposing said second anode portion so as to enable electrons to flow by field emission from said first cathode portion of said first unitary field emission structure to said second anode portion of said second unitary field emission structure, and with said second cathode portion spaced from and opposing said first anode portion so so as to enable electrons to flow by field emission from said second cathode portion of said second unitary field emission structure to said first anode portion of said first unitary field emission structure; a third unitary field emission structure having a third cathode portion and a third anode portion; said first unitary field emission structure and said third unitary field emission structure being adjacently disposed with said first cathode portion spaced from and opposing said third anode portion so as to enable electrons to flow by field emission from said first cathode portion of said first unitary field emission structure to said third anode portion of said third unitary field emission structure, and with said third cathode portion spaced from and opposing said first anode portion so as to enable electrons to flow by field emission from said third cathode portion of said third unitary field emission structure to said first anode portion of said first unitary field emission structure; a first charge image plane disposed adjacent and spaced parallel to said second anode portion of said second unitary field emission structure, and a second charge image plane disposed adjacent and spaced parallel to said third anode portion of said third unitary field emission structure; a first dielectric material disposed between said second anode portion and said first charge image plane whereby a first charge storage capacitor is defined by said second anode portion, said first dielectric material, and said first charge image plane, and a second dielectric material disposed between said third anode portion and said second charge image plane whereby a second charge storage capacitor is defined by said third anode portion, said second dielectric material, and said second charge image plane; and means for controlling the flow of electrons from said first cathode portion and said first cathode portion of said first unitary field emission structure, from said second cathode portion of said second unitary field emission structure, and from said third cathode portion of said third unitary field emission structure, thereby controlling writing of charge to or reading of charge from said first charge storage capacitor and said second charge storage capacitor.

Claim 24

A dual access field emission storage device having a single charge storage capacitor for use in a DRAM device, said dual access storage device comprising: a first unitary field emission structure having a first cathode portion and a first anode portion; a second unitary field emission structure having a second cathode portion, a second cathode portion and a second anode portion; said first unitary field emission structure and said second unitary field emission structure being adjacently disposed with said first cathode portion spaced from and opposing said second anode portion so as to enable electrons to flow by field emission from said first cathode portion of said first unitary field emission structure to said second anode portion of said second unitary field emission structure, and with said second cathode portion spaced from and opposing said first anode portion so as to enable electrons to flow by field emission from said second cathode portion of said second unitary field emission structure to said first anode portion of said first unitary field emission structure; a third unitary field emission structure having a third cathode portion and a third anode portion; said second unitary field emission structure and said third unitary field emission structure being adjacently disposed with said second cathode portion spaced from and opposing said third anode portion so as to enable electrons to flow by field emission from said second cathode portion of said second unitary field emission structure to said third anode portion of said third unitary field emission structure, and with said third cathode portion spaced from and opposing said second anode portion so as to enable electrons to flow by field emission from said third cathode portion of said third unitary field emission structure to said second anode portion of said second unitary field emission structure; a charge image plane disposed adjacent to said first anode portion of said first unitary field emission structure; a dielectric material disposed between said first anode portion of said first unitary field emission structure and said charge image plane whereby a charge storage capacitor is defined by said first anode portion, said dielectric material, and said charge image plane; and means for controlling the flow of electrons from said first cathode portion of said first unitary field emission structure, from said second cathode portion and said second cathode portion of said second unitary field emission structure, and from said third cathode portion of said third unitary field emission structure, thereby controlling writing of charge to or reading of charge from said charge storage capacitor.

Claim 25

A dual access field emission storage device having a single charge storage capacitor for use in a DRAM device, said dual access storage device comprising: a first unitary field emission structure having a first cathode portion and a first anode portion; a second unitary field emission structure having a second cathode portion, a second cathode portion and a second anode portion; said first unitary field emission structure and said second unitary field emission structure being adjacently disposed with said first cathode portion spaced from and opposing said second anode portion so as to enable electrons to flow by field emission from said first cathode portion of said first unitary field emission structure to said second anode portion of said second unitary field emission structure, and with said second cathode portion spaced from and opposing said first anode portion so as to enable electrons to flow by field emission from said second cathode portion of said second unitary field emission structure to said first anode portion of said first unitary field emission structure; a third unitary field emission structure having a third cathode portion and a third anode portion; said second unitary field emission structure and said third unitary field emission structure being adjacently disposed with said second cathode portion spaced from and opposing said third anode portion so as to enable electrons to flow by field emission from said second cathode portion of said second unitary field emission structure to said third anode portion of said third unitary field emission structure, and with said third cathode portion spaced from and opposing said second anode portion so as to enable electrons to flow by field emission from said third cathode portion of said third unitary field emission structure to said second anode portion of said second unitary field emission structure; a charge image plane disposed adjacent to said first anode portion of said first unitary field emission structure; a dielectric material disposed between said first anode portion of said first unitary field emission structure and said charge image plane whereby a charge storage capacitor is defined by said first anode portion, said dielectric material, and said charge image plane; and means for controlling the flow of electrons from said first cathode portion of said first unitary field emission structure, from said second cathode portion and said second cathode portion of said second unitary field emission structure, and from said third cathode portion of said third unitary field emission structure, thereby controlling writing of charge to or reading of charge from said charge storage capacitor.

Claim 26

The bidirectional field emission device of claim 4, wherein said at least one control gate includes: a first gate member of a third layer in parallel with said surface disposed adjacent the tip means of said first cathode portion in layered spaced relationship above/below said first cathode portion for controlling emissions of electrons therefrom; and a second gate member of a fourth layer in parallel with said surface disposed adjacent the tip means of said second cathode portion in layered spaced relationship below/above said second cathode portion, for controlling emission of electrons therefrom.

Claim 27

The bidirectional field emission device of claim 22, wherein said third and fourth layers are external to the region intermediate said first and second layers.