# US 7,609,815 B2 · High brightness—multiple beamlets source for patterned X-ray production

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,609,815 B2
- Document ID: US7609815B2
- Status: Granted
- Kind: B2
- Application number: 11/757,137
- Filed: 2007-06-01
- Published: 2008-02-28
- Granted: 2009-10-27
- Earliest claimed: 2006-06-01
- Assignees: The Regents of the University of California
- Inventors: Ka-Ngo Leung; Qing Ji; William A. Barletta; Ximan Jiang; Lili Ji
- Web page: https://patentgrep.com/patent/US7609815B2

## CPC

- G01N 23/203: Measuring back scattering
- 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
- G01V 5/20: Detecting prohibited goods, e.g. weapons, explosives, hazardous substances, contraband or smuggled objects
- H01J 3/025: {Electron guns using a discharge in a gas or a vapour as electron source (gas-filled discharge tubes with gaseous cathodes H01J15/00)}
- H01J 3/04: Ion guns
- H01J 27/024: {Extraction optics, e.g. grids}
- H01J 35/00: X-ray tubes
- H01J 37/045: {Beam blanking or chopping, i.e. arrangements for momentarily interrupting exposure to the discharge}
- H01J 37/077: Electron guns using discharge in gases or vapours as electron sources
- H01J 37/08: Ion sources; Ion guns
- H01J 37/3172: {Maskless patterned ion implantation}
- H01J 37/3174: {Particle-beam lithography, e.g. electron beam lithography}
- H01J 37/3177: {Multi-beam, e.g. fly's eye, comb probe}
- H01J 2235/06: Cathode assembly
- H01J 2235/068: Multi-cathode assembly
- H01J 2237/0435: Multi-aperture
- H01J 2237/061: Construction
- H01J 2237/06366: Gas discharge electron sources
- H01J 2237/06375: Arrangement of electrodes
- H01J 2237/3171: patterned
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02)
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)

## Abstract

Techniques for controllably directing beamlets to a target substrate are disclosed. The beamlets may be either positive ions or electrons. It has been shown that beamlets may be produced with a diameter of 1 μm, with inter-aperture spacings of 12 μm. An array of such beamlets, may be used for maskless lithography. By step-wise movement of the beamlets relative to the target substrate, individual devices may be directly e-beam written. Ion beams may be directly written as well. Due to the high brightness of the beamlets from extraction from a multicusp source, exposure times for lithographic exposure are thought to be minimized. Alternatively, the beamlets may be electrons striking a high Z material for X-ray production, thereafter collimated to provide patterned X-ray exposures such as those used in CAT scans. Such a device may be used for remote detection of explosives.

## Claims

### Claim 1

A method of patterned beamlet extraction, comprising:
a) supplying a multicusp plasma source substantially containing a plasma;
b) providing an extractor electrode abutting the plasma,
i) the extractor electrode comprising:
(1) a plurality of apertures that pass through a conductive plasma side in direct contact with the plasma,
(2) through a bulk insulator, and
(3) continuing through a conductive exit side, wherein at least one of the extractor electrode apertures are electrically connected with the conductive exit side as the aperture gasses through the bulk insulator;
ii) the extractor electrode comprising one side of the multicusp plasma source; and
c) controllably biasing the conductive exit side of one or more of the apertures in the extractor electrode to extract a pattern of beamlets.

### Claim 2 (depends on 1)

The method of patterned beamlet extraction of claim 1, wherein the contrallably biasing step in the extractor electrode is relative to the conductive plasma side.

### Claim 3 (depends on 1)

The method of patterned beamlet extraction of claim 1, wherein the beamlets are positive ion beamlets.

### Claim 4 (depends on 1)

The method of patterned beamlet extraction of claim 1, wherein the beamlets are electron beamlets.

### Claim 5 (depends on 4)

The method of patterned beamlet extraction of claim 4, further comprising:
a) providing a biased electron beamlet target sufficiently biased for X-ray production at a certain energy;
b) impinging the electron beamlet onto the biased target, thereby producing X-rays; and
e) collimating the X-rays to form a collimated X-ray output.

### Claim 6 (depends on 4)

The method of patterned beamlet extraction of claim 4, further comprising:
a) providing a biased electron beamlet target sufficiently biased for X-ray production at a certain energy.

### Claim 7 (depends on 1)

The method of patterned beamlet extraction of claim 1, wherein the controllably biasing step comprises:
a) biasing the exit side of the extractor electrode so as to electrostatically pull the beamlet from the multicusp plasma source.

### Claim 8 (depends on 7)

The method of patterned beamlet extraction of claim 7, wherein the biasing the exit side step comprises:
a) applying to the exit side a relative voltage of greater than 10 volts higher than the plasma side to stop extraction of an ion beam from the extractor.

### Claim 9 (depends on 7)

The method of patterned beamlet extraction of claim 7, wherein the biasing the exit side step comprises:
a) applying to the exit side a relative voltage of more than −5 volts lower than the plasma side to extract an electron beam from the extractor.

### Claim 10 (depends on 1)

The method of patterned beamlet extraction of claim 1, comprising:
a) directing the beamlets to a target substrate.

### Claim 11 (depends on 10)

The method of patterned beamlet extraction of claim 10, comprising:
a) processing the target substrate with standard photolithographic techniques to allow for maskless photolithography.

### Claim 12 (depends on 10)

The method of patterned beamlet extraction of claim 10, comprising:
a) biasing the target substrate relative to the plasma to allow for maskless ion implantation.

### Claim 13

A device for patterned beamlet extraction comprising:
a) a multicusp ion source for forming a plasma;
b) an extractor electrode comprising one side of the multicusp ion source, said extractor electrode including a plurality of apertures that pass through from the conductive plasma side of the ion source through a bulk insulator, and continuing through a conductive exit side, wherein at least one of the extractor electrode apertures are electrically connected with the conductive exit side as the aperture passes through the bulk insulator; and,
c) means for controllably biasing the conductive exit side of one or more of the apertures in the extractor electrode to extract a pattern of beamlets.

### Claim 14

A device for patterned beamlet extraction comprising:
a) a multicusp ion source having a plasma;
b) computer controlled means whereby selectable patterns of electron beamlets are extracted from the plasma;
c) a target biased relative to the plasma to impinge at least one of the electron beamlets to produce X-rays; and,
d) a collimator proximally located to the target, whereby collimated patterned X-rays are produced.

### Claim 15 (depends on 14)

The device for patterned beamlet extraction of claim 14, comprising:
a) a substrate positioned to be exposed by the collimated patterned X-rays, which is thereby exposed without a mask.

### Claim 16

A device for remote scanning, comprising:
a) a multicusp ion source having a plasma;
b) computer controlled means whereby selectable patterns of collimated X-rays are produced from electron beamlets extracted from the plasma;
c) a detector disposed to detect X-ray transmission and scatter from the selectable patterns of collimated X-rays as the X-rays pass through a test subject; and
d) a computer to analyze data input from the detector so as to provide a computed axial tomograph (CAT) scan.

### Claim 17 (depends on 16)

The device for remote scanning of claim 16, comprising:
a) a detector disposed to detect test subject generated Compton X-ray backscatter from the selectable patterns of collimated X-rays from the test subject;
b) a computer to analyze data input from the detector so as to provide a presence of a specific chemical species present in the test subject.

### Claim 18

A method of patterned beamlet extraction for the production of X-rays, comprising:
a) supplying a multicusp plasma source substantially containing a plasma;
b) providing an extractor electrode abutting the plasma,
i) the extractor electrode comprising:
(1) a plurality of apertures that pass through a conductive plasma side in direct contact with the plasma,
(2) through a bulk insulator, and,
(3) continuing through a conductive exit side, wherein at least one of the extractor electrode apertures are electrically connected with the conductive exit side as the aperture passes through the bulk insulator;
ii) the extractor electrode comprising one side of the multicusp plasma source; and
c) controllably biasing the conductive exit side of one or more of the apertures in the extractor electrode to extract a pattern of electron beamlets;
d) providing a biased electron beamlet target sufficiently biased for X-ray production at a certain energy; and,
e) impinging the electron beamlet onto the biased target, thereby producing X-rays.

### Claim 19 (depends on 18)

The method of patterned beamlet extraction of claim 18, further comprising:
collimating the X-rays to form a collimated X-ray output.