Imported SU-8 photoresist series solves the insufficient aspect ratio issue of standard photoresists under UV lithography. It exhibits very low light absorption in the near-ultraviolet range (360nm-400nm) and delivers uniform exposure across the entire photoresist layer, enabling thick-film patterns with vertical sidewalls and high aspect ratios.
Product Introduction
Imported SU-8 photoresist series solves the insufficient aspect ratio issue of standard photoresists under UV lithography. It exhibits very low light absorption in the near-ultraviolet range (360nm-400nm) and delivers uniform exposure across the entire photoresist layer, enabling thick-film patterns with vertical sidewalls and high aspect ratios.
SU-8 Photoresist Lithography Process
Spin-coat SU-8 photoresist formulation onto the substrate with a coating thickness ranging from several micrometers to hundreds of micrometers. Pre-bake the coated wafer and cool it down to room temperature. For baking, a hot plate with uniform heating and precise temperature control is preferred; blast drying ovens are prohibited, as they cause premature surface curing which hinders solvent evaporation from inner photoresist layers. After cooling, align a negative photomask with the coated wafer and perform exposure under mercury lamp UV irradiation with a dosage of 10-250mJ/cm². Post-exposure bake the wafer at optimized temperature and duration, then immerse it in developer solution for development, followed by nitrogen blow drying.
Advantages of SU-8 Photoresist
1. SU-8 photoresist has extremely low absorbance at near-UV wavelengths (356nm-400nm). Uniform exposure is achieved throughout the resist layer, producing thick film patterns with vertical sidewalls and ultra-high aspect ratios.
2. SU-8 photoresist features excellent mechanical properties, outstanding chemical resistance and superior thermal stability.
3. SU-8 crosslinks upon UV irradiation as a chemically amplified negative photoresist, capable of fabricating complex patterns such as stepped structures.
4. SU-8 is electrically insulating and can be directly utilized as an insulating layer during electroplating.
Thanks to these comprehensive advantages, SU-8 is widely adopted in MEMS, chip packaging and microfabrication industries. Fabricating high-aspect-ratio microstructures and microparts with SU-8 has become a mature novel technology in microfabrication. For microfluidic chip manufacturing, SU-8 is primarily used for rapid prototyping of PDMS microfluidic chips via soft lithography molding.
