Advanced photomask repair technology for 65nm lithography (3)

The 65nm photomasks have to meet tight specifications and improve the production yield due to high production cost. The 65nm optical lithography was thought to have two candidates, 157nm and 193nm. However, at the advent of immersion lithography, it is certain that 193nm lithography will be adopted. Therefore, we decided to develop the FIB machine, SIR7000FIB, proior to the EB machine. We optimized repair conditions of FIB system, SIR7000FIB, and evaluated this system. First, we demonstrated minute defect repair using about 15nm defect mask. Then, we confirmed that the repeatability of repair accuracy was below 7nm on a MoSi HT mask patterned 360nm and 260nm L&S patterns with opaque and clear defects by AFM. Consequently, we have achieved the target specifications of this system.