HIGH-PERFORMANCE ACRYLIC POLYMERS FOR CHEMICALLY AMPLIFIED PHOTORESIST APPLICATIONS

Chemically amplified resists have recently achieved importance as materials useful for high density microlithographic applications requiring submicron imaging. In an effort to extend the chemical amplification concept to applications requiring thick film resists, we have developed a family of acrylic polymers which provide high performance, aqueous developing positive resists when formulated with the appropriate photo-acid generators. The polymers were prepared from methyl methacrylate (MMA), t-butyl methacrylate (TBMA) and methacrylic acid (MAA), each of which serves a separate function in the formed terpolymer. An unusual degree of control over the aqueous development kinetics can be achieved by manipulation of the terpolymer composition. The lithographic properties of resist formulations based on these polymers have been examined employing optical exposure at wavelengths from 248 to 514 nm, and e-beam exposure.