Light propagation through gratings with periods as small, as lambda/20 is i
nvestigated computationally by use of the multiple multipole method in two
dimensions. High image contrast: is evident close to the grating. Strong ev
anescent decay of the high spatial frequency components is observed with th
e region of high contrast shrinking linearly as the period of the grating i
s decreased. Simulations were performed for TE and TM polarizations with th
e TM polarization providing the dominant contrast compared with TE, which i
s strongly attenuated owing to the polarizing effect of the gratings. These
results show good promise for optical contact lithography in the evanescen
t near field of a shadow mask to attain feature sizes smaller than lambda/2
0. (C) 2000 Optical Society of America OCIS codes: 050.1940, 050.1950, 220.
3740, 220.4000, 220.4610, 260.5430.