Investigation of half-tone phase shift mask with FIB and blue laser repair

We discuss a duplicate repairing process for opaque repair by means of a Ga⁺ focussed ion beam (FIB) and a blue laser scanning on a MoSiON phase shift mask. We show the pattern fidelity and edge roughness on the wafer and photomask substrates. The aerial images and intensity profiles produced by the AIMS tool show the fine resolution capability. Although somewhat resolved, we must consider the specifications of CD control for next generation devices such as design rules of 0.15 μm. We evaluate the printability of the half-tone phase shift mask with i-line and KrF steppers after defect repair. We also confirm the accuracy of edge repair, Ga+ deep implantation effects and the environmental stability of FIB and blue laser repair tools. Finally, we measure the topography of the repaired photomask by AFM and AIMS