Characterization of AZ-2415 as a negative electron resist

The use of AZ-2415 as a negative electron resist is described. The effects of electron dose, optical dose, and development time on the resist line profiles are investigated. A low optical dose leads to wider and thicker developed negative lines, but with a lower contrast than lines exposed with a higher optical dose. An increase in development time results in a higher contrast which is accompanied by a significant increase in the electron dose required to maintain a fixed linewidth. A good overall process scheme would avoid both the low optical dose area and the shortest development times in favor of values of these parameters that offer greater linewidth control. Using a 0.5-µm initial film thickness, an electron dose of 80 to 120 µC/cm², an optical dose of 333 mJ/cm², and a 15-s development in 1:3.5 AZ-2401:H2O produce submicrometer resist patterns that provide excellent resistance to plasma etching.