There are two main groups of developers: solvent-based and aqueous-alkaline developers. The solvent-based ones are intended mainly for PMMA e-beam resists, for CSAR 62 and also for special polymer based products. In this process, solvents such as methylisobutylketone (MIBK), IPA (partly with water) for PMMA, amyl acetate, MIBK, DEK, DEM, xylol for CSAR 62 and ethylbenzene as well as hexane are used for the protective coating.
The use of a cascade is recommended for optimum performance of the developer and for the highest cleanliness during immersion development. The development often takes place in only one container.
For some applications are universal developers of advantage, i.e. developers which are simultaneously well suited for a variety of resist families. Multilayer systems can in this case be developed in one step, and no change of the developer in between is required.
X AR 600-50/2 is a new, very sensitive and highly selective developer for AR-P 617. The dark erosion is very low even at longer development times. Layers of PMMA or CSAR 62 are not attacked, which is especially important for multi-layer processes.
To evaluate the suitability of various developers for CSAR 62, Dr. Lothar Hahn (Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology) kindly provided various substrates which had previously been exposed to 100 kV e-beam irradiation (dose variations).
Our highly sensitive e-beam resist AR-P 617 is frequently used in two-layer processes, mostly in combination with PMMA, for the production of lift-off architectures like e.g. T-gates.
Some of our customers use alkali-sensitive aluminium substrates. This leads to problems if the metal surface should not be etched in this process.
In our product information, we recommend developer AR 300-26 for the development of AR-P 5320, our positive photoresist for lift-off applications. A few users however prefer to work with MIF-developers.
The use of aqueous-alkaline developers on alkali-sensitive substrates like aluminium is problematic, because the substrate is similarly attacked during the development step.
For a development of exposed CSAR 62 resist films generally performed by immersion development with development times of approximately 30-60 seconds, developers AR 600-546, 600-548 and 600-549 are well suited.