MICROTECH has developed a complete microlithographic process for cylindrical surfaces. Such a process is suited for the fabrication of thin film coils, line arrays or generic patterns on the side surface of a cylinder, through the following steps:
  1. Surface cleaning and polishing to optical quality
  2. Coating with metal or dielectric thin film
  3. Coating with resist
  4. Laser writing of the pattern
  5. Resist processing
  6. Wet etching
  7. Plating
Patterning resolution down to 5 micrometers can be achieved, including the plating process. Steps 3, 4 and 7 are very dependent on the special shape of the substrate and can be accomplished through specific equipement available from MICROTECH:

Resist deposition system. This special equipement allow the deposition of a thin and uniform resist layer on cylindrical surfaces. A resist thickness in the 1 to 5 micron range can be programmed. The substrate diameter can range between 1 and 100 mm.

3-D Laser pattern generator. By combining precision substrate rotation and raster laser exposure, a conductive or dielectric discretionary pattern can be obtained. MICROTECH has already applied this technique in the following cases:

  1. fabrication of superconducting coils on niobium-coated quartz cylinders, for gravitational wave detectors
  2. LN2 cooled chip carriers for infrared detector arrays
  3. fabrication of thin-film toroidal coils for current sensing applications
  4. fabrication of large diameter coils on copper-coated silica or anodised aluminum, for reprographic applications
See details of the example above in our 3-D lithography picture gallery