Spin Coat and Spray Coat Photoresist for MEMS Photolithography

Rogue Valley Microdevices provides both spray coat photoresist and spin coat photoresist processes to support MEMS photolithography on silicon wafers. Our MEMS foundry processes 100 mm, 150 mm, and 200 mm wafers, allowing engineers to select the resist coating method that best fits their device architecture and fabrication process.

Request a Quote

Photoresist Spin Coat Materials and Capabilities

Successful lithography requires careful control of photoresist materials and processing parameters. Our engineers help customers select photoresist systems that match device materials, etch chemistries, and pattern requirements.

  • Positive photoresist patterning
  • Lift-off Resist for metal patterning
  • Thick photoresist for MEMS structures
  • Specialty resist coatings for microfabrication
  • Polyimide
  • SU8 permanent resist

Supported Wafer Sizes and Materials

  • Silicon
  • Silicon on Insulator
  • Quartz
  • Sapphire
  • Glass
  • GaN on Silicon
  • Silicon Carbide
  • Other specialty substrates
  • 100 mm wafers
  • 150mm wafers
  • 200 mm wafers

Spray Coat Photoresist for High-Topography MEMS Structures

Many MEMS devices include deep cavities, tall structures, or non-planar surfaces that challenge traditional spin-coated photoresist. Spray coat photoresist solves this problem by applying resist uniformly across complex wafer topography.

At our MEMS foundry, we use spray coat lithography to achieve conformal photoresist coverage on silicon wafers with deep features, trenches, or high-aspect-ratio microstructures. This capability enables reliable photolithography on wafers that contain previously etched MEMS features or thick deposited films.

Spray coating distributes photoresist as a fine mist across the wafer surface, allowing the resist to coat sidewalls and recessed structures that spin coating cannot reach effectively.

Advantages of Spray Coated Photoresist

Spray coat resist provides several advantages for MEMS fabrication:

  • Uniform resist coverage over deep topography
  • Improved coating on etched trenches and cavities
  • Reliable lithography on high-aspect-ratio MEMS structures
  • Reduced resist thinning near step edges
  • Better pattern fidelity across complex microstructures

MEMS Applications for Spray Coat Lithography

These benefits make spray coating particularly valuable for advanced MEMS wafer fabrication and MEMS Applications for Spray Coat Lithography

Engineers often use spray coat photoresist during later fabrication steps when wafers already contain significant surface relief.

Typical applications include:

  • Patterning on deep reactive ion etched (DRIE) silicon structures
  • Lithography over thick MEMS structural layers
  • Patterning on wafers with etched cavities or trenches
  • Microfluidic channel fabrication
  • Optical MEMS device processing
  • BioMEMS and lab-on-chip structures

By combining spray coat photoresist with precision mask alignment and wafer photolithography, Rogue Valley Microdevices enables reliable patterning across complex MEMS device architectures.