Layer thickness values of Atlas R and Atlas S are preadjusted to 10 μm at a spin speed of 1000 rpm. It is recommended to perform the subsequent tempering step on the hotplate at 95 °C for 5 min. Temperature ramps or stepwise drying, e.g. 65 °C for 2 minutes, followed by 95 °C for 4 minutes, can improve the resolution. Both resists can be structured by i-line or broadband UV exposure. Prior to irradiation, substrates should be cooled to room temperature. It is recommended to perform the following tempering step for cross-linking on the hotplate at 105 °C for 2 min. Ramps or stepwise cross-linking procedures like e.g. 65
°C for 2 minutes, followed by 95 °C for 7 minutes and 105 °C for 2 minutes, can improve the resolution. In
general, the stability of resists increases with higher temperatures and longer bake times, but this requires on the
other side longer development times. The use of temperature ramps is also recommended for cooling since
cooling too fast may result in stress cracking.
AR 300-12 is recommended as standard developer, but also AR 600-07 (fast development) or AR 600-70 (gentle development) is suitable. If AR-N 4600-10 (S) is used for development, no dark erosion is observed even after comparably long development times. If the development with AR 300-12 is performed for too long, increased dark erosion of AR-N 4650-10 may result, and a too
long development with AR 600-70 can even cause complete removal. Stopper AR 600-60 is recommended for a particularly
residue-free rinsing after development, followed by rinsing with DI water. It is also possible to rinse resist layers
immediately after development directly with DI water and to dry them on the hotplate. The sensitivity for a layer thickness of 10 μm is about 110 – 160 mJ/cm2 in the broadband UV range (process description on page 3).
Coated structures of AR-N 4650-10 (R) can be removed with thinner AR 300-12 or AR 600-70. Depending on the degree of cross-linking (dose, temperature and bake time), required removal times may be considerably longer than 30 minutes.