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APPLICATIONS OF TECHNOLOGY:

• Lithography on flat or curved substrates
  
• Ion implantation/doping
• Stent manufacturing

ADVANTAGES:

• Better focusing effects for smaller image sizes (less than 50 nm)
• Reduces aberrations
  
• Can be used for curved substrates
  
• Table-top size footprint
• Designed for high throughput and high current density
  
• Beams can be manipulated independently

ABSTRACT:

The Berkeley Lab self-focusing direct or proximity print system eliminates the complicated optics used by conventional focused ion beam and ion projection lithography (IPL) systems to achieve pattern demagnification. Instead of a simple one-to-one projection of the mask feature sizes found in most direct print systems, the Berkeley Lab system optimizes the beam focusing electric field lines around the extraction apertures of an electronically controlled universal pattern generator (see universal pattern generator description, IB-1387,1579) or a fixed pattern mask (see IB-1383) to reduce pattern size by up to a factor of thirty. The focusing effect at the apertures is due to the curvature of the equi-potential surfaces. Because no reduction or accelerator column or electrostatic beam scanning components are necessary, the apparatus is compact - with a footprint the size of a table-top.

The system designed by Ka-Ngo Leung can be operated with multiple H+ , H- or other species of ion beams without a crossover. Because the focused ion beamlets are independent of each other, the system can pattern large or curved substrate areas without distortions and with high throughput. It is ideal for generating small pattern features with dimensions of 50 nm or less.

Berkeley Lab has also developed a proximity print system that includes a counterbore around the plasma electrode apertures or the extraction electrode apertures or both. The shape of the equipotential electric field lines around the aperture which serve to focus the exiting ion beam can be altered by adjusting the counterbore hole size relative to the aperture diameter. Optimizing this effect significantly reduces aberrations and increases focusing to achieve smaller image sizes. Under experimental conditions it has been shown to reduce aberrations by as much as 80% and achieve spot sizes 2.5 times smaller than identical systems without a counterbore. The invention achieves reduction image printing with a single extractor.

STATUS:

• U.S. Patent #6,924,493 and U.S. Patent #7,084,407. Available for licensing or collaborative research

REFERENCE NUMBER: IB-1529, IB-1780

FOR MORE INFORMATION:

Please see US Patent Application Serial # 367,664

SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:

• High Current Focused Ion Beam System (IB-1217)
• Ion Beam Projection Lithography (IPL) for Minimizing Pattern Distortion and Mask Replacement/Repair(IB-1383)
• Simplified and Compact Electron Cyclotron Resonance (ECR) Ion Source (IB-1562)
• Universal Pattern Generator for Micro-Ion Beam Reduction Lithography (IB-1387, IB-1579)