Investigations of the development rate of irradiated PMMA Microstructures in deep X-ray lithography

Deep X-ray lithography is a fabrication method for producing microstructure with high aspect ratios using resist layers of 100 µm to several millimeters. We have measured the development rates of noncrosslinked PMMA microstructures (minimum size 30 µm diameter) at room temperature for dose values between 2 and 16 kJ/cm3. We used dip development and megasonic supported development (10 W/cm2). The development rates cover three orders of magnitude, and the megasonic supported development rate is about four times larger than that for dip development.