Electron Beam Lithography


Electron beam lithography can achieve the smallest features at ~10nm. It is a maskless technique that, like the laser writer, has uses a CAD file for the pattern and can write the pattern directly on the substrate. The electron beam current of Penn State's Raith 5200 is continously variable with a minimum spotsize of 2nm which is why such small features can be exposed.  The spatial resoultion is very good and has control of pitch's on the order of angstroms.

The Raith 5200 at Penn State has a specialized stage that allows it to expose substrates up to 10 mm thick and with extreme topography and curved surfaces.

Resolution < 10 nm
Overlay < 15 nm


Raith EBPG5200 - Electron Beam Lithography

The Raith EBPG5200 system is used to directly write fine nanometer features in resist. Features as small as 14nm have been achieved. The system has a custom stage with 10mm of Z-height travel for writing curved surfaces as well as parts with extreme topography. The system can handle small parts through 150mm (6 inch) wafers and 5" x 5" mask plates.

The Raith EBPG5200 has been paired with the data (pattern) preparation software Layout Beamer which is easy to use as well as having advanced features such as proximity effect correction.



  • 50 & 100kV beam energy
  • Thermal field emission source for a stable high current beam
  • 2nm Gaussian beam size
  • 1mm deflection field size
  • Proximity correction
  • 0.125nm main field resolution
  • 100Mhz beam stepping frequency
  • Stage has 210mm X-Y travel and 10mm Z travel
  • 6Å accuracy on stage location
  • Flexible 2D marker recognition for multi-layer direct write
  • External alignment microscope with height meter


  • Small parts
  • 3" wafers (on small parts holders)
  • 100mm (4 inch) wafers
  • 150mm (6 inch) wafers
  • 5" x 5" mask plates

Electron Beam Resists Typically Used:

  • PMMA: high resolution positive resist used for liftoff and sometimes for etching
  • ZEP 520A: high resolution positive resist good for etching and can be used for liftoff of thin metals
  • ZEP 7000-22: moderate resolution, but fast positive resist used primarily for making photomasks
  • MMA-MAA: copolymer for use under PMMA as for the bi-layer liftoff process
  • NEB-31 high resolution, fast negative resist used mostly for etching
  • XR1541/HSQ: ultimate resolution negative resist used for etching mask or as part of device



  • Single layer liftoff with PMMA
  • Single layer liftoff with ZEP520
  • Bi-Layer liftoff with PMMA & P(MMA/MAA) (co-polymer)
  • Bi-Layer liftoff with XR1541 (HSQ) & PMMA

Pattern for Etch:

  • ZEP520
  • NEB31
  • HSQ

Additional Equipment Details


  • 8nm line width @100kV
  • 10nm lines within a 100mm field size ±3nm @100kV
  • 15nm lines within a 250mm field size ±3nm @100kV
  • 20nm lines within a 500mm field size ±3nm @100kV

Stitching Accuracy:

  • ±15 nm for 100µm main field @100kV
  • ±20 nm for 250µm main field @100kV
  • ±25 nm for 500µm main field @100kV
  • ±25 nm for 500µm main field @50kV

Overlay Accuracy:

  • ±15 nm for 100µm main field @100kV
  • ±20 nm for 250µm main field @100kV
  • ±30 nm for 500µm main field @100kV
  • ±25 nm for 500µm main field @50kV

Direcct Write Accuracy:

  • ±15 nm for 100µm main field @100kV
  • ±20 nm for 250µm main field @100kV
  • ±25 nm for 500µm main field @100kV
  • ±25 nm for 500µm main field @50kV

RIMS Name: Litho: EBPG 5200 Vistec e-beam (MSC)
Training: Visit the Equipment & Training Information