1nm of local CD accuracy for 45nm-node photomask with low sensitivity CAR for e-beam writer

We achieved highly accurate Local CD in the vicinity of 1nm with the newly developed low sensitivity chemically amplified resist (CAR) for the e-beam reticle writer, EBM-6000. We applied shot noise model to estimate Line Edge Roughness (LER). According to the estimation result, LER is improved by increasing the threshold dosage. We evaluated the performance of newly developed low sensitivity CAR. Local CD accuracy, LER, pattern resolution and drawing time are evaluated. We concluded that the performance with the low sensitivity CAR was good enough to produce photomasks for 45nm half pitch (HP) devices.