Cellector: A new software tool for the support of cell projection in combination with variable shape electron beam lithography for mask and direct write applications.

A new software tool for the support of cell projection in combination with variable shape electron beam lithography for mask making and direct write a pplication is described. The program has been designed and developed for th e WePrint 200, a new variable shape electron beam lithography system from L eica Microsystems Lithography GmbH, which includes a powerful cell projecti on unit. The WePrint 200 allows the use of 20 different mini-reticles with one set of apertures. Starting from the chip layout, Cellector calculates the layout structures w hich are potential candidates for cell projection and exposable using mini- reticles. The determination of the mini-reticle candidates takes place with consideration of the pattern neighbourhood relationship and the hierarchic ally layout description. For each mini-retide, the program also calculates statistical values, like the number of calls per mini-reticle and the amoun t of flash reduction. These values help the user select the optimal mini-re ticle set for the cell projection step. With the application of PROXECCO1 a full mask or full chip e-beam proximity correction is available to achieve high pattern fidelity. The correction is achieved for variable shape beam exposure through dose modulation and for mini-reticle projection through ge ometrical pattern optimisation. The benefit of throughput enhancement using cell projection is directly cor related with the regularity of the chip layout and with the reduction of fl ashes by using mini-reticle. In the paper throughput enhancements by applic ation of cell projection are given for different kind of chips.