Photolithography Services

Platypus Technologies offers services in photolithography for fabrication of patterned surfaces. Applications include fabrication of chemical sensors, biosensors, electrodes, and MEMs devices.

Photolithography is a process that uses ultraviolet (UV) light to pattern a light-sensitive coating (known as photoresist) deposited on a substrate.  A mask is placed atop the photoresist to block UV light from illuminating certain areas, so that only unmasked regions are exposed to light.  The geometric pattern in the photoresist is revealed by removing the unprocessed areas using an appropriate organic or aqueous solvent.  Platypus Technologies stocks both negative and positive photoresists for diverse applications.

The photoresist pattern is transferred to a thin metal film via two different techniques: metal lift-off or wet etching.

Metal Lift-Off:  Metal lift-off is a process where a thin metal film is deposited atop the patterned photoresist.  Next, the photoresist is dissolved to reveal the pattern of the metal film.

Wet Etching:  For wet etching, the photoresist is deposited and patterned atop the metal film.  Areas of the metal that are not protected by the photoresist are removed by carefully selected liquid chemicals.  The photoresist is removed by a solvent, or via O2 plasma, to reveal the pattern of the metal film.

Available surface pre- and post-treatment preparation methods include O2 plasma or deposition of silanes (e.g. HMDS, fluorinated silanes), self-assembled monolayers and protective coatings.

Photolithography services at Platypus Technologies are carried in a dedicated cleanroom facility (class 1000) equipped with environmental controls, ensuring high quality parts for our customers.

Applications include SU-8 patterned wafers for microfluidics, inter-digitated electrodes, electrochemical sensors, beam-splitting optical plates, pixel arrays, indium tin oxide (ITO) electrodes, flexible electrodes, and more.


  • 365-nm highly collimated UV exposure system
  • Photoresist types: positive, lift-off, SU-8.
  • Substrates: glass, silicon, metals, ceramics, polyimide.
  • Minimum feature resolution: 5-µm
  • Circular substrates up to 6”-dia
  • Square substrates up to 4”x4”

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