Imaging characteristics of poly(methyl methacrylate) at vacuum ultraviolet wavelengths

We report the depth versus exposure characteristics of poly(methyl methacrylate) (PMMA) in the vacuum ultraviolet (VUV) region from 59 to 128 nm. Calculated absorption coefficients of the PMMA are also presented. The depth of the features on the PMMA were in the range of 20-80 nm created by 1-50 mJ cm(-2) exposures and were measured with an atomic force microscope (AFM). We found that the AFM can reliably measure depth differences of only 2 nm, The sensitivity of the AFM permits exposures to be reduced for high resolution microscopy and holography even in the case of highly absorbing films. (C) 1997 American Vacuum Society.