Finite element modeling of ion-beam lithography masks for pattern transfer distortions

As one of the Next Generation Lithographies, Ion-beam Projection Lithography (IPL) will be subject to strict error budgets for the sub-130 nm regime and will require high pattern placement accuracy. Meeting these stringent conditions in a timely and cost-effective manner will depend upon accurate predictions of the mechanical distortions induced in IPL stencil masks during fabrication and pattern transfer. To simulate pattern transfer, finite element (FE) structural models of the stencil masks have been developed to predict distortions due to the fabrication of voids in stressed mask membranes. In this paper, an application of FE modeling for stencil masks has been demonstrated using both the IBM Falcon pattern and more uniform patterns (to simulate the advantages of complementary masks).