A method of determining photoresist image modulation was investigated and utilized, in determining the effect of varied resist thicknesses on modulation for both a high and low contrast system. Modulation is defined in terms of maximum and minimum energy required to clear a line/space pattern in the resist image. In This study, useing the resist as the threshold detector, chemical contrast is compared to physical contrast in terms of modulation. Shipley\u27s MF314 and MF312 are the two different contrast development systems used. This study has shown that beyond 11700 Å of resist thickness, physical modulation is reduced to a measure of difference between Emax and Emin, and tells very little about the true modulation. This is in part due to a loss of developer interaction with modulation at resists thicker than 11000 Å. This holds for both MF312 and MF314
