Integrated Photonics Cleanroom - a researcher in a cleanroom suit uses the Karl Zuss MA6 contact aligner
Zepler Cleanrooms

Lithography

Lithography is the technique by which design patterns are transferred to a sensitive resist at multiple stages of the fabrication process.

About our lithography capability

Part of the nanofabrication cleanrooms

Lithography is the technique by which design patterns are transferred to a sensitive resist at multiple stages of the fabrication process.

Our lithography capability features leading Electron Beam Lithography (EBL), writing to 5 nanometres (nm) feature size. Unique to UK academic research we also have a Deep Ultraviolet (248nm) scanner for feature size down to 180nm.

We also provide traditional broadband UV photolithography using manual mask aligners, for feature size down to 1 micrometre (µm). 

The mask aligners operate in contact or proximity modes. They handle a range of substrate sizes, from small pieces up to 200 millimetre (mm) wafers, in front and backside alignment modes. We can fit the aligners with optical filters to allow G/H/I line wavelength selection.

Alternative nanopatterning techniques such as microcontact printing and nano imprint lithography are also available.  

Our wafer bonder can perform pre-bond alignment via a mask aligner. This achieves micron-scale bond alignment accuracy.  

We offer a versatile capability for resist processing, including multiple spin, bake, and development lines.

We work with many types of resists including:

  • positive and negative tone UV photoresists
  • electron beam resists
  • thick film photoresists up to 100µm
  • SU-8 epoxy photoresists
  • laminated epoxy and acrylic photosensitive materials
Integrated Photonics Cleanroom - a researcher in a cleanroom suit uses the Karl Zuss MA6 contact aligner
Karl Zuss MA6 Contact Aligner

 

Processes and equipment

Spin and bake

 

  • CEE Apogee modules for separated optical and electron beam resist spin and bake 

 

Optical photolithography (Broadband/G/H/I Line compatible) 

 

  • EVG620 & Karl Suss MA6 Broadband contact aligners
  • 200mm frontside alignment 
  • 200mm front to backside alignment, bonding alignment, UV nanoimprint processes. Minimum standard feature size 1µm
  • optimised for positive, negative, and LoF resists, polymers (SU-8, bonding) 
  • substrate sizes up to 200mm (other chucks available to handle smaller substrates) 

 

Wafer bonding

 

  • EVG 520 capable of performing thermo-compression, Fusion, Anodic, Eutectic and Adhesive bonding
  • process temperature up to 500°C
  • contact force up to 20 kilonewtons
  • substrate sizes from pieces to 150mm wafers
  • compatible with EVG 620TB for pre-bond wafer alignment 

 

Resist processing

 

  • optimised processes for scanner, e-beam, and optical lithography applications
  • established positive, negative, lift-off, and image reversal resist processes
  • polymer and spin-on glass coatings for bonding, structural materials, microfluidics, and encapsulation
  • thickness ranges from nm to > 100µm
  • dedicated resist spinners
  • 300°C maximum temperature hotplate for substrates up to 200mm
  • dehydration and resist bake ovens
  • mask cleaner and lift-off station
  • O2 microwave plasma ashing  
  • dedicated wet resist strip stations 

 

A researcher in a cleanroom suit uses the wafer bond tool
Wafer bond tool - the EVG520

 

Contact us

For more information or to book the facilities, get in touch: zepler.cleanrooms@soton.ac.uk