Bleachable dyed resist - investigation of its process latitude in comparison with standard resists

The process latitude of a resist with a bleachable dye component is investigated theoretically with respect to most interesting lithographic parameters and compared with standard dyed and undyed as well as with heavy PAC-loaded resists. Bleachable dyed resists are found to increase the process latitude especially on highly reflective substrates with topography. This is due to the attenuation of irregular reflections and the interference of the light by a stronger absorption, and by reduction of the bulk effect, which is caused by contrast enhancement due to the bleachable dye component. Calculations are made using a modification of Dill's model and the process simulator LITHSIM.