Charge-transfer complexes applied to photolithography by formation of a portable conformable mask and as a contrast-enhancement layer

A contrast enhancing system using a photosensitive layer on top of a conventional photoresist is described. This light-sensitive system, whose optical properties change upon exposure, is based on intermolecular charge-transfer complexes (CTC). The image of the mask is defined in the top layer at the wavelength of the CTC absorption maximum. After fixation of the built-on-mask, a flood exposure is performed to replicate the image on the photoresist bottom layer. The physicochemical properties and the application to photolithography of such a system are described. Two systems improving the imaging capabilities are investigated: built-on-mask technique and contrast-enhancement layer.