Integrated cost and productivity learning in CMOS semiconductor manufacturing : G. A. LEONOVICH, A. P. FRANCHINO, W. J. MILLER, and U. E. TSOU. IBM Journal of Research and Development39(1/2), 20 (January/March 1995)

Abstract

A novel lithographic technique- CARL - is introduced that allows the optical resolution limit to be overcome by a controllable size reduction of resist spaces, i.e. chemical widening (‘amplification’) of adjacent resist lines. The process is based on the treatment of specially developed anhydride-containing resist for NUV or DUV exposure with aqueous solutions of aminic reagents and can be carried out on standard puddle development tracks. Thus, using the CARL principle in a positive tone bilayer/O2-RIE scheme (Si-CARL) and a 0.4 NA i-line optic, spaces down to 150 nm can be printed and transfered to a 1.8 μm thick planarizing layer without linewidth variation. The new CARL resist chemistry, preliminary process characteristics and some prospects, e.g. enlarged alignment budget in critical mask steps, are described and first results are discussed.