Mold method for forming vacuum field emitters and method for forming diamond emitters

Claim 1

A method of fabricating a microtip emitter comprising the steps of: a. creating a cavity within a solid molding material to create a molding substrate having a top surface around the cavity, the cavity having a pre-determined geometric shape; b. depositing a semiconductor material into the cavity such that at least a first portion of the semiconductor material is characterized by small grain size and conforms to the geometric shape of the cavity, wherein depositing a semiconductor material is done without implanting ions as nucleation sites onto the solid molding material; and c. removing the mold material from around the cavity, leaving a solid microtip emitter formed of the semiconductor material and having an emitter shape conforming to the geometric shape of the cavity.

Claim 2

A method of fabricating a microtip emitter comprising the steps of: a. creating a cavity within a solid molding material to create a molding substrate having a top surface around the cavity, the cavity having a pre-determined geometric shape; b. depositing a semiconductor material into the cavity such that at least a first portion of the semiconductor material is characterized by small grain size and conforms to the geometric shape of the cavity, wherein depositing a semiconductor material is done without implanting ions as nucleation sites onto the solid molding material; and c. removing the mold material from around the cavity, leaving a solid microtip emitter formed of the semiconductor material and having an emitter shape conforming to the geometric shape of the cavity.

Claim 3

A method of fabricating an microtip electron emitter using a re-usable mold comprising the steps of: a. creating a cavity within a solid mold material to create a re-usable molding substrate having a top surface around the cavity, the cavity having a pre-determined geometric shape; b. depositing a first layer of material into the cavity such that the first material layer conforms to the geometric shape of the cavity and covers the top surface of the molding substrate but does not fill the cavity; c. depositing diamond over the first material layer such that the diamond replicates the shape of the cavity and covers a top surface of the first material layer; d. separating the molding substrate from the first material layer; and e. removing the first layer of material from around the diamond, leaving a solid microtip emitter formed of the diamond and having an emitter shape conforming to the geometric shape of the cavity.

Claim 4

A method of fabricating an microtip electron emitter using a re-usable mold comprising the steps of: a. creating a cavity within a solid mold material to create a re-usable molding substrate having a top surface around the cavity, the cavity having a pre-determined geometric shape; b. depositing a first layer of material into the cavity such that the first material layer conforms to the geometric shape of the cavity and covers the top surface of the molding substrate but does not fill the cavity; c. depositing diamond over the first material layer such that the diamond replicates the shape of the cavity and covers a top surface of the first material layer; d. separating the molding substrate from the first material layer; and e. removing the first layer of material from around the diamond, leaving a solid microtip emitter formed of the diamond and having an emitter shape conforming to the geometric shape of the cavity.

Claim 12

A method of fabricating a microtip emitter comprising the steps of: a. creating a cavity within a solid molding material to create a molding substrate having a top surface around the cavity, the cavity having a pre-determined geometric shape; b. depositing a semiconductor material into the cavity such that at least a first portion of the semiconductor material is characterized by small grain size and conforms to the geometric shape of the cavity; c. depositing a second layer of material above the top surface of the molding substrate whereby a substrate of the second layer of material is formed integral to the emitter, wherein the second layer of material is diamond; and d. removing the mold material from around the cavity after the second layer has been deposited, leaving a solid microtip emitter formed of the semiconductor material and having an emitter shape conforming to the geometric shape of the cavity.

Claim 13

A method of fabricating a microtip emitter comprising the steps of: a. creating a cavity within a solid molding material to create a molding substrate having a top surface around the cavity, the cavity having a pre-determined geometric shape; b. depositing a semiconductor material into the cavity such that at least a first portion of the semiconductor material is characterized by small grain size and conforms to the geometric shape of the cavity; c. depositing a second layer of material above the top surface of the molding substrate whereby a substrate of the second layer of material is formed integral to the emitter, wherein the second layer of material is diamond; and d. removing the mold material from around the cavity after the second layer has been deposited, leaving a solid microtip emitter formed of the semiconductor material and having an emitter shape conforming to the geometric shape of the cavity.

Claim 23

A method of fabricating a diamond microtip emitter having enhanced field emission performance comprising the step of providing a pre-determined and controlled concentration of carbon graphite content within the diamond wherein the carbon graphite content of the diamond is optimized to reduce the turn-on voltage of the emitter field.

Claim 24

A method of fabricating a diamond microtip emitter having enhanced field emission performance comprising the step of providing a pre-determined and controlled concentration of carbon graphite content within the diamond wherein the carbon graphite content of the diamond is optimized to reduce the turn-on voltage of the emitter field.

Claim 25

A method of fabricating a diamond microtip emitter having enhanced emission performance comprising the step of depositing diamond having a predetermined and controlled concentration of carbon graphite content within the diamond wherein the step of providing a pre-determined and controlled concentration of carbon graphite content within the diamond includes adjusting a ratio of a carbon bearing species to a hydrogen bearing species during the step of depositing the diamond.

Claim 26

A method of fabricating a diamond microtip emitter having enhanced emission performance comprising the step of depositing diamond having a predetermined and controlled concentration of carbon graphite content within the diamond wherein the step of providing a pre-determined and controlled concentration of carbon graphite content within the diamond includes adjusting a ratio of a carbon bearing species to a hydrogen bearing species during the step of depositing the diamond.

Claim 28

A method of fabricating a diamond microtip emitter having enhanced field emission performance comprising the step of depositing diamond having a pre-determined and controlled concentration of carbon graphite content within the diamond wherein the step of providing a pre-determined and controlled concentration of carbon graphite content within the diamond includes adjusting a deposition energy level during the step of depositing the diamond.

Claim 29

A method of fabricating a diamond microtip emitter having enhanced field emission performance comprising the step of depositing diamond having a pre-determined and controlled concentration of carbon graphite content within the diamond wherein the step of providing a pre-determined and controlled concentration of carbon graphite content within the diamond includes adjusting a deposition energy level during the step of depositing the diamond.

Claim 30

A method of fabricating a device having an array of microtip emitters comprising the steps of: a. applying a masking layer on a molding substrate; b. defining a pattern for the array on the molding substrate by creating windows in the masking layer; c. etching cavities within the molding substrate at the windows defining the pattern for the array, each cavity having a predetermined shape including a lower surface defining a geometry of a microtip; d. cleaning the molding substrate; e. depositing a film of semiconductor material across the surface of the molding substrate and within the cavities, to form a solid emitter structure of the semiconductor material inside of, and conforming to the shape of, each cavity; and f. removing the molding substrate to leave an array of microtip emitters monolithically arranged on a substrate of the semiconductor material.

Claim 31

A method of fabricating a device having an array of microtip emitters comprising the steps of: a. applying a masking layer on a molding substrate; b. defining a pattern for the array on the molding substrate by creating windows in the masking layer; c. etching cavities within the molding substrate at the windows defining the pattern for the array, each cavity having a predetermined shape including a lower surface defining a geometry of a microtip; d. cleaning the molding substrate; e. depositing a film of semiconductor material across the surface of the molding substrate and within the cavities, to form a solid emitter structure of the semiconductor material inside of, and conforming to the shape of, each cavity; and f. removing the molding substrate to leave an array of microtip emitters monolithically arranged on a substrate of the semiconductor material.

Claim 34

A method of fabricating a device having an array of microtip emitters comprising the steps of: a. applying a masking layer on a molding substrate; b. defining a pattern for the array on the molding substrate by creating windows in the masking layer; c. etching cavities within the molding substrate at the windows defining the pattern for the array, each cavity having a predetermined shape including a lower surface defining a geometry of a microtip; d. depositing a film of semiconductor material, wherein the semiconductor material is diamond, across the surface of the molding substrate and within the cavities, to form a solid emitter structure of the semiconductor material inside of, and conforming to the shape of, each cavity, wherein the step of depositing the diamond film is carried out in a sequence of smooth and standard diamond deposition steps, the smooth and standard diamond deposition steps each defined by process parameters including deposition energy and pressure, the smooth deposition step operated at predetermined deposition energy and pressure levels to initiate diamond growth within the cavity and to create small grain boundaries in the diamond near the tip, and the standard deposition step operated at predetermined deposition energy and pressure levels to accelerate diamond growth in the cavities and on the molding substrate with larger grain boundaries in the diamond; and f. removing the molding substrate to leave an array of microtip emitters monolithically arranged on a substrate of the semiconductor material.

Claim 35

A method of fabricating a device having an array of microtip emitters comprising the steps of: a. applying a masking layer on a molding substrate; b. defining a pattern for the array on the molding substrate by creating windows in the masking layer; c. etching cavities within the molding substrate at the windows defining the pattern for the array, each cavity having a predetermined shape including a lower surface defining a geometry of a microtip; d. depositing a film of semiconductor material, wherein the semiconductor material is diamond, across the surface of the molding substrate and within the cavities, to form a solid emitter structure of the semiconductor material inside of, and conforming to the shape of, each cavity, wherein the step of depositing the diamond film is carried out in a sequence of smooth and standard diamond deposition steps, the smooth and standard diamond deposition steps each defined by process parameters including deposition energy and pressure, the smooth deposition step operated at predetermined deposition energy and pressure levels to initiate diamond growth within the cavity and to create small grain boundaries in the diamond near the tip, and the standard deposition step operated at predetermined deposition energy and pressure levels to accelerate diamond growth in the cavities and on the molding substrate with larger grain boundaries in the diamond; and f. removing the molding substrate to leave an array of microtip emitters monolithically arranged on a substrate of the semiconductor material.

Claim 43

A method of fabricating a gated electron emitting device comprising the steps of: a. applying a masking layer to a molding substrate; b. defining a pattern for an array of diamond microtip emitter structures on the molding substrate by creating windows in the masking layer; c. etching cavities within the molding substrate at the windows defining the pattern for the array, each cavity having a predetermined geometric shape; d. depositing a diamond film across the surface of the molding substrate and within the cavities, to form a solid diamond emitter structure inside, and conforming to the shape, of each cavity, each emitter structure having a microtip; e. removing the molding substrate to leave an array of diamond microtip emitter structures monolithically arranged on a diamond substrate; f. depositing a layer of dielectric material to cover the diamond substrate and the array of diamond microtip emitter structures except for the microtips; g. depositing a metallic layer over the dielectric material; and h. bonding a lower surface of the diamond substrate to a conductive layer.

Claim 44

A method of fabricating a gated electron emitting device comprising the steps of: a. applying a masking layer to a molding substrate; b. defining a pattern for an array of diamond microtip emitter structures on the molding substrate by creating windows in the masking layer; c. etching cavities within the molding substrate at the windows defining the pattern for the array, each cavity having a predetermined geometric shape; d. depositing a diamond film across the surface of the molding substrate and within the cavities, to form a solid diamond emitter structure inside, and conforming to the shape, of each cavity, each emitter structure having a microtip; e. removing the molding substrate to leave an array of diamond microtip emitter structures monolithically arranged on a diamond substrate; f. depositing a layer of dielectric material to cover the diamond substrate and the array of diamond microtip emitter structures except for the microtips; g. depositing a metallic layer over the dielectric material; and h. bonding a lower surface of the diamond substrate to a conductive layer.

Claim 45

A method of fabricating a cap gated electron emitting device comprising the steps of: a. applying a masking layer to a molding substrate; b. defining a pattern for an array of diamond microtip emitters on the molding substrate by creating windows in the masking layer; c. etching cavities within the molding substrate at the windows defining the pattern for the array, each cavity having a predetermined geometric shape; d. depositing a diamond film across the surface of the molding substrate and within the cavities, to form a solid diamond emitter inside, and conforming to the shape, of each cavity; e. removing the molding substrate to leave an array of diamond microtip emitter structures monolithically arranged on a diamond substrate; f. bonding a lower surface of the diamond substrate to a conductive layer, the conductive layer supported by a supporting substrate; and g. attaching a conductive cap over the array to define a gap between the microtips in the array and a lower surface of the cap, the cap being electrically isolated from each of the other structures of the device.

Claim 46

A method of fabricating a cap gated electron emitting device comprising the steps of: a. applying a masking layer to a molding substrate; b. defining a pattern for an array of diamond microtip emitters on the molding substrate by creating windows in the masking layer; c. etching cavities within the molding substrate at the windows defining the pattern for the array, each cavity having a predetermined geometric shape; d. depositing a diamond film across the surface of the molding substrate and within the cavities, to form a solid diamond emitter inside, and conforming to the shape, of each cavity; e. removing the molding substrate to leave an array of diamond microtip emitter structures monolithically arranged on a diamond substrate; f. bonding a lower surface of the diamond substrate to a conductive layer, the conductive layer supported by a supporting substrate; and g. attaching a conductive cap over the array to define a gap between the microtips in the array and a lower surface of the cap, the cap being electrically isolated from each of the other structures of the device.

Claim 49

A method of fabricating a vacuum microelectronic device having a diamond microtip emitter as a cathode comprising the steps of: a. forming a cavity in a molding substrate, the molding substrate comprising a doped semiconductor; b. depositing a layer of dielectric material into part of the cavity and across a top surface of the molding substrate; c. depositing a diamond film into the remaining portion of the cavity and over the layer of dielectric material such that the diamond film in the cavity forms a microtip emitter having an emitter tip; d. removing a portion of the molding substrate from a back side of the substrate to expose a portion of the dielectric layer proximate the tip of the emitter; and e. partially removing the dielectric layer above the tip of the emitter to expose the emitter thereby forming a diamond microtip diode with one or more isolated segments of the molding substrate functioning as an anode.

Claim 50

A method of fabricating a vacuum microelectronic device having a diamond microtip emitter as a cathode comprising the steps of: a. forming a cavity in a molding substrate, the molding substrate comprising a doped semiconductor; b. depositing a layer of dielectric material into part of the cavity and across a top surface of the molding substrate; c. depositing a diamond film into the remaining portion of the cavity and over the layer of dielectric material such that the diamond film in the cavity forms a microtip emitter having an emitter tip; d. removing a portion of the molding substrate from a back side of the substrate to expose a portion of the dielectric layer proximate the tip of the emitter; and e. partially removing the dielectric layer above the tip of the emitter to expose the emitter thereby forming a diamond microtip diode with one or more isolated segments of the molding substrate functioning as an anode.

Claim 53

A method of fabricating a vacuum microelectronic device having a diamond microtip emitter as a cathode comprising the steps of: a. forming a cavity in a molding substrate, the molding substrate comprising a semiconductor; b. creating a diffusion layer in the molding substrate, the diffusion layer comprising highly doped segments of the semiconductor arranged on at least one side of the emitter; c. growing an epi layer of the semiconductor material in the molding substrate between the diffusion layer and the cavity; d depositing a layer of dielectric material into part of the cavity and across a top surface of the molding substrate; e depositing a diamond film into the remaining portion of the cavity and over the layer of dielectric material such that the diamond film in the cavity forms a microtip emitter having an emitter point; f removing a portion of the molding substrate from a back side of the substrate to expose a portion of the dielectric layer proximate the tip of the emitter; and g partially removing the dielectric layer above the tip of the emitter to expose the emitter thereby forming a diamond microtip diode with one or more isolated segments of the diffusion layer functioning as an anode.

Claim 54

A method of fabricating a vacuum microelectronic device having a diamond microtip emitter as a cathode comprising the steps of: a. forming a cavity in a molding substrate, the molding substrate comprising a semiconductor; b. creating a diffusion layer in the molding substrate, the diffusion layer comprising highly doped segments of the semiconductor arranged on at least one side of the emitter; c. growing an epi layer of the semiconductor material in the molding substrate between the diffusion layer and the cavity; d depositing a layer of dielectric material into part of the cavity and across a top surface of the molding substrate; e depositing a diamond film into the remaining portion of the cavity and over the layer of dielectric material such that the diamond film in the cavity forms a microtip emitter having an emitter point; f removing a portion of the molding substrate from a back side of the substrate to expose a portion of the dielectric layer proximate the tip of the emitter; and g partially removing the dielectric layer above the tip of the emitter to expose the emitter thereby forming a diamond microtip diode with one or more isolated segments of the diffusion layer functioning as an anode.

Claim 57

A method of fabricating a vacuum microelectronic device having a diamond microtip emitter as a cathode comprising the steps of: a. forming a cavity in a molding substrate, the molding substrate comprising a highly doped semiconductor; b. depositing a layer of dielectric material into part of the cavity and across a top surface of the molding substrate; c. depositing a diamond film into the remaining portion of the cavity and over the layer of dielectric material such that the diamond film in the cavity forms a microtip emitter having an emitter point; d. removing a portion of the molding substrate from a back side of the substrate to expose a portion of the dielectric layer proximate the tip of the emitter; and e. partially removing the dielectric layer above the tip of the emitter to expose the emitter thereby forming a diamond microtip diode with one or more isolated segments of the molding substrate functioning as an anode.

Claim 58

A method of fabricating a vacuum microelectronic device having a diamond microtip emitter as a cathode comprising the steps of: a. forming a cavity in a molding substrate, the molding substrate comprising a highly doped semiconductor; b. depositing a layer of dielectric material into part of the cavity and across a top surface of the molding substrate; c. depositing a diamond film into the remaining portion of the cavity and over the layer of dielectric material such that the diamond film in the cavity forms a microtip emitter having an emitter point; d. removing a portion of the molding substrate from a back side of the substrate to expose a portion of the dielectric layer proximate the tip of the emitter; and e. partially removing the dielectric layer above the tip of the emitter to expose the emitter thereby forming a diamond microtip diode with one or more isolated segments of the molding substrate functioning as an anode.

Claim 59

A method of fabricating a microtip emitter comprising the steps of: a. creating a cavity within a solid molding material to create a molding substrate having a top surface around the cavity, the cavity having a pre-determined inverted pyramidal shape; b. depositing diamond semiconductor material into the cavity such that the semiconductor material conforms to the geometric shape of the cavity; c. removing the mold material from around the cavity, leaving a solid microtip emitter formed of the semiconductor material and having an pyramidal emitter shape conforming to the geometric shape of the cavity; and d. sharpening the microtip of the electron emitting structure after removal of the mold material.

Claim 60

A method of fabricating a microtip emitter comprising the steps of: a. creating a cavity within a solid molding material to create a molding substrate having a top surface around the cavity, the cavity having a pre-determined inverted pyramidal shape; b. depositing diamond semiconductor material into the cavity such that the semiconductor material conforms to the geometric shape of the cavity; c. removing the mold material from around the cavity, leaving a solid microtip emitter formed of the semiconductor material and having an pyramidal emitter shape conforming to the geometric shape of the cavity; and d. sharpening the microtip of the electron emitting structure after removal of the mold material.

Claim 62

A method of fabricating a microtip emitter comprising the steps of: a. creating a cavity within a solid molding material to create a molding substrate having a top surface around the cavity, the cavity having a pre-determined geometric shape; b. depositing a semiconductor material into the cavity such that the semiconductor material conforms to the geometric shape of the cavity, wherein the step of depositing a semiconductor is characterized by an increasing grain size of said semiconductor; and c. removing the mold material from around the cavity, leaving a solid microtip emitter formed of the semiconductor material and having an emitter shape conforming to the geometric shape of the cavity.

Claim 63

A method of fabricating a microtip emitter comprising the steps of: a. creating a cavity within a solid molding material to create a molding substrate having a top surface around the cavity, the cavity having a pre-determined geometric shape; b. depositing a semiconductor material into the cavity such that the semiconductor material conforms to the geometric shape of the cavity, wherein the step of depositing a semiconductor is characterized by an increasing grain size of said semiconductor; and c. removing the mold material from around the cavity, leaving a solid microtip emitter formed of the semiconductor material and having an emitter shape conforming to the geometric shape of the cavity.