M. Nagase et al., NANO-SCALE FLUCTUATIONS IN ELECTRON-BEAM RESIST PATTERN EVALUATED BY ATOMIC-FORCE MICROSCOPY, Microelectronic engineering, 30(1-4), 1996, pp. 419-422
The resist pattern fluctuations on the nano-scale are successfully obs
erved using a dynamic force mode AFM. A scaling analysis based on the
fractals applies to the AFM images for quantitative evaluation of the
fluctuations. The standard deviation of width fluctuations in a ZEP re
sist pattern is 2.8 nm. The scaling analysis confirms that the surface
morphology of the pattern sidewall is almost the same as that of the
resist film lightly exposed by an electron beam. The main cause of the
fluctuation is structures with a diameter of 20-30 nm which are compo
sed of large groups of molecules.