Chemical amplification of resist lines: a novel sub-half-micron bilayer resist tehnique for NUV and deep-UV lithography

Abstract

The Chemical Amplification ofResist Lines (CARL) and its practicability in a bilayer/O2RIE processing scheme (Si-CARL) is described. Novel anhydride-containing resins and photoactive compounds of the diazonaphthoquinone type are used in top resists with sub-halfmicron resolution capability in both NUV and KrF excimer laser lithography. The silylating treatment of alkaline developed, positive tone top resist patterns with aqueous solutions of bisaminoalkyl-oligodimethylsiloxanes can be performed on standard puddle development tracks at room temperature. A concomitant linewidth increase is used to reduce dimensions of resist openings, e.g. trenches or contact holes, with good process control. Equal lines and spaces were achieved by treatment of slightly overexposedtopresist patterns. Modified top resistpatterns are transferred intothe underlying 1 .3 -1.8 j.tm thick planarizing layer without linewidth variationtogive steepprofiles and high aspect ratios. Thus, 0.3 tm resolution is obtained with KrF excimer laser exposure (0.35 NA). The attained resolution of 0.3 tm features with g-line exposure (0.55 NA) represents ak-factor of 0.38, according to the Rayleigh relation. This paper discusses process and lithographic performance characteristics of the novel Si-CARL process.