Ws. Han et Ks. Chung, TRANSMITTANCE CONTROLLED MASK (TCM) - ITS APPLICATION TO OPTICAL PROXIMITY CORRECTION AND TOPOGRAPHY, Journal of the Korean Physical Society, 30(3), 1997, pp. 557-562
A new type of mask named a TCM (Transmittance Controlled Mask) is prop
osed to correct for optical proximity and to overcome problems caused
by topography. This mask, made from a conventional transmission mask w
ith chromium patches on top where light attenuation is needed, is eval
uated with different transmittances and is applied to the patterns whi
ch require local light attenuation caused, by a resist thickness diffe
rence or by light scattering over topography. Aerial image simulations
and experiments were carried out comparatively from the view of image
fidelity over topography, ft was found that good pattern formation wa
s possible with a properly controlled transmittance mask regardless of
the topography, which is a real situation in actual devices.