Oligosaccharide/Silicon-Containing Block Copolymers for Lithography Applications

The need to overcome feature-size limitations in conventional lithography has led to the development of new patterning techniques using block copolymer templates. Ideal block copolymer systems for these applications have high etch contrast between blocks to promote good feature resolution and high chi-parameters to achieve small features. An additional desireable attribute is polymers with high silicon content such that they form a robust oxide mask during reactive ion etching with oxygen. To achieve etch contrast, these silicon-containing polymers can be incorporated into a block copolymer where the adjacent block is organic and etches easily. It is also observed that, in some cases, incorporating silicon into one of the blocks increases chi compared to similar silicon-deficient block copolymers. Here we will present three new block copolymer systems exhibiting cylindrical morphologies that incorporate fast-etching oxygen-rich oligosaccharides coupled to a silicon-containing polymer. The silicon-containing block provides sufficient etch resistance to achieve robust patterns in addition to promoting high chi parameters which allows access to cylinder diameters between 2 and 5nm.