Ion beam etching process simulation for the pattern transfer of photoresist diffraction gratings generated by holography

The manufacturing process for diffraction gratings based on interference lithography results at first in a resist surface relief pattern. However, the majority of applications demand grating structures in the inorganic substrate material itself. Commonly, a modification of the grating profile with regard to an optimized diffraction efficiency is necessary. Therefore a number of different etching methods may be employed. For the very often applied dry etching processes an intuitively accessible forecast of the resulting etched profile is virtually impossible. This is caused by the distinct angular dependence of the etching rate. In this contribution a new advanced simulation tool is introduced. Theoretical as well as experimental results will be presented. The high flexibility of the whole process chain will be illustrated. The graphical capabilities of the tool offer a deeper insight into the mechanics of the pattern transfer.