Due to the fast-paced development of photolithography since the 1990s, only a short summary of the different techniques and applications can be given here. For in-depth information on the multitude of facts, technologies and procedures presented in each chapter, the added references should be consulted.
For an optimum handling of EUV lithography using the RWTH system, a sensitivity range of 30-40 mJ/cm² is desired. A Medusa 82 sample supplemented with 2.5 % photoacid generator (PAG) already reached this target range. These investigations will be continued within the scope of a research project.
The addition of photoacid generators (PAGs) can significantly increase the sensitivity of Medusa 82 (see Resist Wiki “Medusa with photoacid generator”). Another option is to add a PEB after e-beam exposure. Even if substrates were previously stored for several days, the sensitivity significantly increases depending on the temperature and the duration of the PEB.
One disadvantage of HSQ and Medusa 82 is the comparably low sensitivity, which can however be increased by an addition of photoacid generators.
Our research team successfully developed a negative resist with high resolution and plasma etching stability in oxygen: Medusa 82. Already with the first samples, it was possible to achieve the properties of HSQ.