Specific Process Knowledge/Lithography/4562

Feedback to this section: click here

AZ 4562 is a positive UV photoresist for thick coatings (5µm and above).

Spin coating

Spin curves for AZ 4562 using 60s spin-off and 60s@100°C softbake on LabSpin, and 30s spin-off and 300s@100°C 1mm proximity softbake on Gamma

The thickest coating using a normal spin cycle is probably 10-15µm. However, reducing the spin-off time to a few seconds at 2000rpm has successfully been used to increase the coating thickness beyond 20µm on a Gamma coater. The substrate is rested for 1min before softbake in order to reduce the edge bead height.

Development

The recommended development speed for AZ 4562 is 2µm/min. A 6.2µm resist film thus requires 3min development, usually as three 60s puddles of TMAH (AZ 726 MIF). 10µm AZ 4562 has successfully been developed using 4x60s development