As the feature sizes of integrated circuits shrink, thinner photoresist coating should be used in order to avoid high aspect ratio which can cause pattern collapse. Especially for 193 nm lithography, photoresist coating is too thin to subsequent etching step. One of the solutions to this problem is using hardmasks which have good etch selectivity to adjacent layers. In this paper, silicon-based anti-reflective spin-on hardmasks (Si-SOH) are described. One of the major problems of silicon based polymers in the hardmask compositions is poor storage stability because silanol group is reactive enough to condense each other, which can instigate molecular weight increase to yield gel-type particles. The storage stability of our hardmask materials have been improved by thermodynamically controlled synthesis and reactive mask strategy. Especially the reactive masked silanol groups can take part in crosslinking reaction under the process conditions without additional deprotection step. Although this strategy could encounter intermixing problems with other layers, we can produce silicon-based hardmasks without any deleterious effects. These hardmasks show antireflective properties and great etch selectivity to both photoresists and organic hardmasks (C-SOH).

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