Lithography

Lithography is a process where a pattern written or transferred to a substrate. It uses light, ions or electron energy into photo and electron sensitive resists. At E6NanoFab, Electron-Beam Lithography, Laser-Writer, and Mask-Aligner tools serve to pattern a variety of materials from sub-10 nanometers up to 100’s of microns over large sample areas.

System Overview

The EBL system is used to directly write fine features in resist with feature’s line widths smaller than 8 nm. The system has a custom stage with 10mm of Z-axis travel for writing over curved surfaces. The system can handle small samples through 200mm (8 inch) wafers and 7″ x 7″ mask plates.

 

Technical specifications:

  • 50 & 100kV beam energy
  • Electron beam current 50 pA – 200 nA
  • Thermal field emission source
  • 1.9 nm Gaussian beam size at 100 KV
  • Automated aperture change
  • 1mmx1mm deflection field size
  • 100 MHz pattern generator frequency
  • Stage has 210mm X-Y travel and 10mm Z travel
  • 1.5 Å accuracy on stage location
  • External alignment microscope
  • Proximity correction
  • Small pieces to 200mm (8 inch) wafers
  • 7″ x 7″ mask plates
  • Resolution: < 8nm line width @100 kV with 100 μm field size
  • Stitching Accuracy: <±10 nm @100 kV with 100 μm field size
  • Overlay accuracy: <±10 nm @100 kV with 100 μm field size

Location
E6-01-Cleanroom, Class 100

Contact
Dr Sandipan Chakraborty
Email: elesnch@nus.edu.sg
Tel: 660 16304

System Overview

DWL 66fs is a high resolution pattern generator for direct writing and mask making.

Technical Specifications

  • Direct patterning for maximum substrate size: 9” x 9”
  • Minimum substrate size: 10 x 10 mm²
  • Maximum write area: 200 x 200 mm²
  • Substrate thickness: 0 to 6 mm
  • Illumination source: Diode Laser (405 nm) for standard positive resist exposure
  • Direct writing with minimum feature size of 0.6 μm
  • High accuracy overlay alignment of 400 nm
  • Vector Exposure Mode offers five different line widths
  • Complex topographies patterning capability for micro-optical
  • Components or any other gray scale application
  • Interferometer stage position resolution: 10 nm

Location
E6-01-03, Class 10 Cleanroom

Contact
Xiao Yun
Email: elexiaoy@nus.edu.sg
Tel: 660 17030

System Overview

The mask aligner operates either in contact or in proximity mode and able to handle a wide range of substrate sizes from small pieces up to 200mm wafers.

Technical Specifications

  • Able to handle substrate size of 25 mm round up to 200 mm round & 200 x2 00mm square
  • Capable to handle mask size ranging from 2”x2” up to 9”x9”
  • DC lamps HG 350 W/S, HG 500 W, HG-XE 500 W
  • X, Y, THETA- alignment stage for motorized operation, resolution 0.1um
  • Alignment gap programmable from 1 to 1,000 micron, resolution at 1 micron
  • MO optics for Highest Uniformity, Diffraction reduction, Focus depth increase
  • Substrate Conformal Imprinting Lithography (SCIL) / PDSM Imprinting Lithography
  • Imprint lithography up to 150mm
  • Wavelength: 350 to 1200 nm
  • TSA alignment accuracy: <0.5μm
  • BSA alignment accuracy:<1.0 um
  • Infra-red (IR) Alignment , BSA alignment accuracy ≤ 1µm
  • UV uniformity: +/-3.5% for 8” wafer
  • Patterning of structures resolution below 0.8 μm
  • Alignment accuracy down to 0.25 μm
  • (SCIL) / PDSM Imprinting Lithography resolution better than 100nm

Location
E6-01-03, Cleanroom, Class 100

Contact
Dr Sandipan Chakraborty
Email: elesnch@nus.edu.sg
Tel: 660 16340

System Overview

ModelKarl Suss MA6

Technical Specifications

  • UV400 Exposure Optics
  • Wavelength: 365nm and 405nm
  • Substrate Size: irregular to standard 2” dia wafer
  • Mask Size: Typical 3” square
  • Wafer Thickness: < 4 mm


Location

E6-02-07, Level 2 Cleanroom, Class 10000

Contact
Musni HUSSAIN
Email: elemh@nus.edu.sg
Tel: 660 17042

System Overview

A procedure used to deposit uniform thin films to flat substrates. Small amount of coating material is applied on the center of the substrate, which is either spinning at low speed or not spinning at all. The substrate is then rotated at high speed in order to spread the coating material by centrifugal force.

Spin coater involves accurately dispensing a liquid onto a flat substrate and then spinning at high speed to achieve a uniform film.

 

Technical Specifications

  • Speeds of up to 6,000 RPM.
  • Irregular sizes 5-50 mm
  • Handle up to 8” wafers on a vacuum chuck.

Location
E6-01-03, Class 100 Cleanroom

Contact
Xiao Yun
Email: elexiaoy@nus.edu.sg
Tel: 660 17030

System Overview

Hot plates are hotplates for soft bake and post exposure bake (PEB) used for baking photoresist which improves adhesion and dry etch resistance. Soft bake to drive off solvents and to solidify the photoresist film.

Technical Specifications

  • Up to 200mm substrates
  • Fast heating
  • Temperature up to 250 degree C
  • Small foot print
  • Easy to operate.

Location
E6-01-03, Class 10 Cleanroom

Contact
Xiao Yun
Email: elexiaoy@nus.edu.sg
Tel: 660 17030

System Overview

The Solvent bench is designed for substrate cleaning, developing pattern after exposure, lift–off pattern transfer schemes and other fabrication operations using solvents.

Technical specifications

  • Stainless steel perforated work space
  • Stainless steel solvent sinks
  • DI Water and N2 Teflon gun
  • Differential pressure gauge to measure the difference in pressure between the bench exhaust and the room

Location
E6-01-03, Class 10 Cleanroom

Contact
Xiao Yun
Email: elexiaoy@nus.edu.sg
Tel: 660 17030