Fabrication
Melting resist technology uses standard semiconductor processes and allows to fabricate microlenses from 10 µm to 2 mm diameter of excellent optical quality for wavelength from the DUV to the IR.
PHOTORESIST PROCESSING
- A thick layer of photoresist is coated onto a fused silica or silicon wafer.
- Resist cylinders is fabricated by photolithography and subsequent developing.
- The cylinders are melted in an oven or on a hot plate at about 150°C.
REACTIVE ION ETCHING
- The resist lenses are transferred in fused silica or Silicon by reactive ion etching (RIE).
- A precise control of the profile by changing the etch rate during the RIE step allows the fabrication of high quality spherical and aspherical microlenses.
