Realisation of irregular quarter-micron patterns in thick resists using an advanced e-beam sensitive TSI process

The TSI process enables a high resolution of lines and spaces in thick resists by e-beam direct writing. The realisation of irregular patterns requires the compensation of the pattern-related backscattering by a proximity correction. The scattering parameters were determined by a new method. The non-complete elimination of the flow effect by an aqueous presilylation development and the pattern-dependent deposited energy cause variable silicon profile angles and impede the accurate CD realisation of irregular patterns. We developed guidelines for the choice of the process parameters enabling the compensation of CD deviations and the preparation of irregular quarter micron patterns in 1.2μm thick resist.