Novel Silicon-Containing Negative Resist for Bilayer Application in Electron Beam Direct Writing

A silicon-containing negative resist for bilayer application in electron beam (EB) direct-writing lithography has been developed. This newly developed EB resist comprises of alkaline soluble ladder type polysiloxane and trichloromethyl triazine. This negative EB resist has a high sensitivity of below 10 µC/cm2, along with a high resolution capability. Using this resist 0.2 µm line and space patterns were clearly delineated, and 0.2 µm rule device patterns were also successfully fabricated. The etching selectivity ratio of this negative resist against the novolak resin in an oxygen plasma was greater than 50, due to its high silicon content. High fidelity pattern transfer could be obtained by using it as a mask of silicon-containing negative resist patterns in a bilayer resist process.