Siegfried Dr. Rer. Nat. Birkle

Chemical amplification of resist lines (CARL)

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/O 2 -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.

Aqueous phase silylation a new route to plasma developable high resolution resists

Abstract A novel O 2 /RIE developable photoresist system with aqueous phase silylation of the exposed areas is presented. The silylation includes a spontaneous crosslinking reaction between the anhydride groups of the base resin and the aminosiloxane silylating reagent. The silylation leads to a considerable growth of the film thickness which is promoted by higher exposure dose, acidity of the exposed resist, normality of the aminosiloxane solution, silylation time and temperature. The system demonstrates several benefits such as fast silylation with existing equipment (puddle development track) at room temperature, high etch resistance of the silylated layer against O 2 /RIE (same as polyphenylmethylsilane), possibility of water inspection after silylation and applicability of the same resist formulation for 366 nm and 248 nm . First i-line stepper experiments gave 0.5μm lines and spaces with an aspect ratio of 4.5.