An investigation of the effects of the molecular weight distribution on the sensitivity of positive electron resists



The molecular weight distribution of two grades of poly(methyl methacrylate) was determined, and the solubility of that polymer in methyl ethyl ketone–2-propanol mixtures was studied. The effects of the molecular weight distribution of the polymer and the strength of the developing solvent on electron resist sensitivity were studied experimentally and compared with a computer model of the electron exposure process. The molecular weight and the molecular weight distribution were found to have a significant effect on the sensitivity of poly(methyl methacrylate) as an electron resist. Increased sensitivity is predicted for higher molecular weight and narrower molecular weight distribution.