Evaluation of defect repair of EUV mask absorber layer

Nano-machining repair technique is relatively new technology for photomask repairing. The advantages of this technique are low substrate damage, precise edge placement accuracy and improved Z height accuracy comparison with Laser zapper or FIB GAE repair techniques. In this work, we have evaluated nano-machining technique capability for EUV mask repair. To get good wafer print results, additional side etch(X bias) and depth etch (Z bias) were needed. Defect repaired region was evaluated using CD-SEM, AFM and wafer print test. Good repair profile and good wafer print results were successfully obtained.