# US 6,498,349 B1 · Electrostatically focused addressable field emission array chips (AFEA's) for high-speed massively parallel maskless digital E-beam direct write lithography and scanning electron microscopy

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- Number: US 6,498,349 B1
- Document ID: US6498349B1
- Status: Granted
- Kind: B1
- Application number: 09/368,919
- Filed: 1999-08-05
- Granted: 2002-12-24
- Earliest claimed: 1997-02-05
- Assignees: UT-Battelle, LLC
- Inventors: Clarence E. Thomas; Larry R. Baylor; Edgar Voelkl; Michael L. Simpson; Michael J. Paulus; Douglas H. Lowndes; John H. Whealton; John C. Whitson; John B. Wilgen
- Web page: https://patentgrep.com/patent/US6498349B1

## CPC

- H01J 3/021: {Electron guns using a field emission, photo emission, or secondary emission electron source}
- B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
- B82Y 40/00: Manufacture or treatment of nanostructures
- H01J 37/073: Electron guns using field emission, photo emission, or secondary emission electron sources
- H01J 37/3174: {Particle-beam lithography, e.g. electron beam lithography}
- H01J 37/3175: {Projection methods, i.e. transfer substantially complete pattern to substrate}
- H01J 37/3177: {Multi-beam, e.g. fly's eye, comb probe}
- H01J 2237/0635: Multiple source, e.g. comb or array
- H01J 2237/31786: Field-emitting cathode
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES

## Abstract

Systems and methods are described for addressable field emission array (AFEA) chips. A method of operating an addressable field-emission array, includes: generating a plurality of electron beams from a pluralitly of emitters that compose the addressable field-emission array; and focusing at least one of the plurality of electron beams with an on-chip electrostatic focusing stack. The systems and methods provide advantages including the avoidance of space-charge blow-up.

## Claims

### Claim 1

An addressable field-emission array, comprising:
a plurality of addressable emitters; and
an on-chip electrostatic focusing stack coupled to said plurality of addressable emitters, wherein the plurality of addressable emitters are controlled using a logical shift register and current regulator circuit.

### Claim 2

An addressable field-emission array, comprising:
a plurality of addressable emitters;
an on-chip electrostatic focusing stack coupled to said plurality of addressable emitters; a plurality of detectors coupled to said plurality of addressable emitters; and a plurality of current copier circuits, each of said plurality of current copier circuits electrically connected to one of said plurality of addressable emitters.

### Claim 3

An addressable field-emission array comprising:
a plurality of addressable emitters;
a plurality of detectors coupled to said plurality of addressable emitters; and
a plurality of current copier circuits, each of said plurality of current copier circuits electrically connected to one of said plurality of addressable emitters.

### Claim 4

An addressable field-emission array, comprising:
a plurality of addressable emitters; and
a plurality of current copier circuits, each of said plurality of current copier circuits electrically connected to one of said plurality of addressable emitters.

### Claim 5 (depends on 4)

The addressable field-emission array of claim 4, further comprising: an on-chip electrostatic focusing stack coupled to said plurality of addressable emitters.

### Claim 6

A method of operating an addressable field-emission array, comprising:
generating a plurality of electron beams from a plurality of emitters that compose said addressable field-emission array; and
focusing at least one of said plurality of electron beams with an on-chip electrostatic focusing stack, wherein said plurality of addressable emitters are powered by a plurality of current copier circuits, each of said plurality of current copier circuits electrically connected to one of said plurality of addressable emitters.

### Claim 7

A method of operating an addressable field-emission array, comprising:
individually addressing each of said plurality of individually addressable emitters with a plurality of current copier circuits;
generating a plurality of electron beams from a plurality of individually addressable emitters that compose said addressable field-emission array; and
focusing at least one of said plurality of electron beams with an electrostatic focusing stack,
wherein the plurality of individually addressable emitters and the electrostatic focusing stack are integrated on the addressable field-emission array.

### Claim 8

A method of operating an addressable field-emission array, comprising:
generating a plurality of electron beams from a plurality of emitters that compose said addressable field-emission array; and
focusing at least one of said plurality of electron beams with an on-chip electrostatic focusing stack;
individually addressing each of said plurality of emitters; and
controlling said plurality of emitters with a logical shift register and current regulator circuit.