Polymer-bound sensitizer in i-line resist formulations

An important component of a photoresist formulation is the photoactive compound. In conventional I-line resist, it is the DNQ molecule. In chemically amplified resists, it is the photoacid generator or the PAG. This component acts as the link between the exposure tool and the photoresist system. While PAGs for the 248 nm or DUV application are plenty, there is little effort in the arena of i-line PAGs. Typically, energy transfer in i-line lithography is achieved by using a DUV PAG in conjunction with an i-line energy transfer agent called sensitizer. This combination works very well, as described by workers before. This paper describes a polymer-bound sensitizer, which while maintaining the performance characteristics of a monomeric sensitizer, also enhances the solubility characteristics and the thermal stability of the resist.