US5399238A — Method of making field emission tips using physic…

Claim 1

Independent Claim 108 words

A method of making field emission tips, comprising the following steps: disposing a continuous layer of a low work function material over a substrate; depositing in situ by physical vapor deposition a non-polymerized randomly patterned etch mask with a relatively high melting point over the low work function material, said etch mask consisting essentially of randomly located discrete nuclei with discontinuities therebetween formed as deposition occurs without coalescence of the nuclei thereby exposing portions of the low work function material beneath the discontinuities; etching the exposed portions of the low work function material; and removing the etch mask thereby forming exposed emission tips of low work function material.

Claim 2

Independent Claim 108 words

A method of making field emission tips, comprising the following steps: disposing a continuous layer of a low work function material over a substrate; depositing in situ by physical vapor deposition a non-polymerized randomly patterned etch mask with a relatively high melting point over the low work function material, said etch mask consisting essentially of randomly located discrete nuclei with discontinuities therebetween formed as deposition occurs without coalescence of the nuclei thereby exposing portions of the low work function material beneath the discontinuities; etching the exposed portions of the low work function material; and removing the etch mask thereby forming exposed emission tips of low work function material.

Claim 3

Independent Claim 116 words

A method of making field emission tips, comprising the following steps: disposing a continuous layer of a base material over a substrate; depositing in situ by physical vapor deposition a non-polymerized randomly patterned etch mask with a relatively high melting point over the base material, said etch mask consisting essentially of randomly located discrete nuclei with discontinuities therebetween formed as deposition occurs without coalescence of the nuclei thereby exposing portions of the base material beneath the discontinuities; etching the exposed portions of the base material to form tips in the base material; and depositing a low work function material over the tips in the base material thereby forming exposed emission tips of low work function material.

Claim 4

Independent Claim 116 words

A method of making field emission tips, comprising the following steps: disposing a continuous layer of a base material over a substrate; depositing in situ by physical vapor deposition a non-polymerized randomly patterned etch mask with a relatively high melting point over the base material, said etch mask consisting essentially of randomly located discrete nuclei with discontinuities therebetween formed as deposition occurs without coalescence of the nuclei thereby exposing portions of the base material beneath the discontinuities; etching the exposed portions of the base material to form tips in the base material; and depositing a low work function material over the tips in the base material thereby forming exposed emission tips of low work function material.

Claim 5

Independent Claim 24 words

The method as recited in claims 1 or 2 wherein the substrate is selected from the group consisting of glass, silicon and a metal.

Claim 6

Independent Claim 19 words

The method as recited in claims 1 or 2 wherein the low work function is less than 4.5 electronvolts.

Claim 7

Independent Claim 17 words

The method as recited in claims 1 or 2 wherein the low work function material is diamond.

Claim 8

Independent Claim 27 words

The method as recited in claims 1 or 2 wherein the etch mask is selected from the group consisting of aluminum-oxide, molybdenum, gold, carbon, graphite, and diamond.

Claim 9

Independent Claim 21 words

The method as recited in claims 1 or 2 wherein the height of the emission tips is at least one micron.

Claim 10

Independent Claim 23 words

The method as recited in claims 1 or 2 wherein the distance between adjacent emission tips exceeds the height of the emission tips.

Claim 11

Independent Claim 21 words

The method as recited in claims 1 or 2 wherein the melting point of the nuclei is at least 1000° C.

Claim 12

Independent Claim 32 words

The method as recited in claims 1 or 2 wherein the physical vapor deposition is provided by one of an ionized metal cluster beam, a liquid metal cluster beam, evaporation or sputtering.

Claim 13

Independent Claim 22 words

The method as recited in claims 1 or 2 wherein the exposed portions etch at a greater rate than the etch mask.

Claim 14

Independent Claim 17 words

The method as recited in claims 1 or 2 wherein the etching is by an ion etch.

Claim 15

Independent Claim 16 words

The method as recited in claims 1 or 2 wherein the etching is without reactive gases.

Claim 16

Independent Claim 17 words

The method as recited in claims 1 or 2 wherein the emission tips assume a pyramid shape.

Claim 17

Independent Claim 26 words

The method as recited in claims 1 or 2 wherein the etching removes all of the etch mask and the emission tips assume a conical-pyramid shape.

Claim 18

Independent Claim 47 words

The method as recited in claims 1 or 2 wherein the etching removes a portion of the etch mask without removing a remaining portion of the etch mask, a second etch removes the remaining portion of the etch mask and the emission tips assume a rectangular-pyramid shape.

Claim 19

Independent Claim 19 words

The method as recited in claims 1 or 2 wherein the etching begins after the deposition of nuclei begins.

Claim 20

Independent Claim 23 words

The method as recited in claims 1 or 2, further comprising installing the emission tips as cold cathodes in a flat panel display.

Claim 21

Dependent Claim 26 words

The method as recited in claim 2 wherein the etch mask is completely removed and the low work function material is deposited on the base material.

Claim 22

Dependent Claim 27 words

The method as recited in claim 2 wherein the etch mask is not completely removed and the low work function material is deposited on the etch mask.

Claim 23

Independent Claim 145 words

A method of making diamond emission tips without photolithography, comprising the following steps: providing a substrate; depositing a continuous layer of a diamond on the substrate; depositing in situ by evaporation or sputtering a non-polymerized randomly patterned etch mask with a relatively high melting point on the diamond, said etch mask consisting essentially of randomly located discrete nuclei with discontinuities therebetween formed as deposition occurs without coalescence of the nuclei thereby exposing portions of the diamond beneath the discontinuities while covering other portions of the diamond beneath the nuclei; etching the exposed portions of the diamond by applying an ion etch after the deposition of nuclei begins, wherein the diamond etches at a greater rate than the etch mask so as to form valleys in the diamond with diamond emission tips therebetween; and removing all of the etch mask thereby exposing the diamond emission tips.

Claim 24

Independent Claim 145 words

A method of making diamond emission tips without photolithography, comprising the following steps: providing a substrate; depositing a continuous layer of a diamond on the substrate; depositing in situ by evaporation or sputtering a non-polymerized randomly patterned etch mask with a relatively high melting point on the diamond, said etch mask consisting essentially of randomly located discrete nuclei with discontinuities therebetween formed as deposition occurs without coalescence of the nuclei thereby exposing portions of the diamond beneath the discontinuities while covering other portions of the diamond beneath the nuclei; etching the exposed portions of the diamond by applying an ion etch after the deposition of nuclei begins, wherein the diamond etches at a greater rate than the etch mask so as to form valleys in the diamond with diamond emission tips therebetween; and removing all of the etch mask thereby exposing the diamond emission tips.

Claim 25

Independent Claim 157 words

A method of making diamond emission tips without photolithography, comprising the following steps: providing a substrate; depositing a continuous layer of a base material on the substrate; depositing in situ by evaporation or sputtering a non-polymerized randomly patterned etch mask with a relatively high melting point on the base material, said etch mask consisting essentially of randomly located discrete nuclei with discontinuities therebetween formed as deposition occurs without coalescence of the nuclei thereby exposing portions of the base material beneath the discontinuities while covering other portions of the base material beneath the nuclei; etching the exposed portions of the base material by applying an ion etch after the deposition of nuclei begins, wherein the base material etches at a greater rate than the etch mask so as to form valleys in the base material with base tips between the valleys; and then depositing diamond over the base material thereby forming exposed diamond emission tips between the valleys.

Claim 26

Independent Claim 157 words

A method of making diamond emission tips without photolithography, comprising the following steps: providing a substrate; depositing a continuous layer of a base material on the substrate; depositing in situ by evaporation or sputtering a non-polymerized randomly patterned etch mask with a relatively high melting point on the base material, said etch mask consisting essentially of randomly located discrete nuclei with discontinuities therebetween formed as deposition occurs without coalescence of the nuclei thereby exposing portions of the base material beneath the discontinuities while covering other portions of the base material beneath the nuclei; etching the exposed portions of the base material by applying an ion etch after the deposition of nuclei begins, wherein the base material etches at a greater rate than the etch mask so as to form valleys in the base material with base tips between the valleys; and then depositing diamond over the base material thereby forming exposed diamond emission tips between the valleys.

Claim 27

Independent Claim 19 words

The method of claims 1 or 2 or 21 or 22 wherein the etch mask consists of the nuclei.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1998-03-20	1998-09-19	1999-03-21	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2002-03-20	2002-09-19	2003-03-21	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2006-03-20	2006-09-19	2007-03-21	$7700.00	Window Closed / Lapsed

Method of making field emission tips using physical vapor deposition of random nuclei as etch mask

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