TeraScanXR: a high sensitivity and throughput photomask inspection system

Abstract

As optical lithography progresses towards 32nm node and beyond, shrinking feature size on photomasks and growing database size provides new challenges for reticle manufacture and inspection. The new TeraScanXR extends the inspection capability and sensitivity of the TeraScanHR to meet these challenges. TeraScanXR launches a new function that can dynamically adjust defect sensitivities based on the image contrast (MEEF) --applying higher sensitivity to dense pattern regions, and lower sensitivity to sparse regions which are lithographically less significant. The defect sensitivity of TeraScanXR for Die-to-Die (DD) and Die-to-Database (DDB) inspection mode is improved by 20-30%, compared with TeraScanHR. In addition, a new capability is introduced to increase sensitivity specifically to long CD defects. Without sacrificing the inspection performance, the new TeraScanXR boosts the inspection throughput by 35%-75% (depending upon the inspection mode) and the dataprep speed by 6X, as well as the capability to process 0.5-1 Terabyte preps for DDB inspection.