Monte-Carlo Based Optical Proximity Correction For The Half-Tone Phase Shift Mask

We developed a Monte-Carlo based optical proximity correction (OPC) program which can be applied to the strong or half-tone phase shift mask (PSM) as well as the binary masks. In previous report [l], we presented smart OPC solutions for binary masks. We showed that manufacturable OPC mask can be obtained by incorporating novel object function and optimization strategy. In this work, we extended the algorithm to PSM. We show the detailed algorithm of our program and several solutions for the OPC of half-tone PSM. One example of our results is shown in Fig. 1. The test pattern is the simple contact hole pattern whose size is 0.4 X 0.4 (AJNA)’. The aerial image for the binary mask is shown in Fig. 1 (a). Fig. 1 (b) shows the aerial image for the half-tone PSM whose transmittance is 9%. Fig. 1 (c) of the solution after OPC for the half-tone PSM shows dramatic enhancement of aerial image quality. Fig. 1 (d) shows the abstraction of the solution of (c) to enhancing the mask manufacturabilty. In this figure, we can find that the aerial image quality is a little degraded comparing with that of (c).