Pattern transfer on mask membranes

Pattern specific emulation is facilitated by the prediction of the distortions due to pattern transfer. Using finite element (FE) methods along with equivalent modeling techniques, it is possible to determine the distortions due to the fabrication of actual mask patterns. This article presents the results of the FE simulation on x-ray lithography masks. Employing the IBM Talon mask design as an example case, the distortions in the pattern area due to the fabrication of the absorbers on the mask membrane were determined. Results are presented for both a uniformly stressed absorber layer and an absorber layer with a unidirectional linear stress gradient.