The ALTA~circleR 3700: Extending the Application Space of the ALTA 3500 Laser Reticle writer

摘要

Critical dimension (CD) uniformity, stripe butting, and composite overlay results from incremental improvements in critical subsystems on the ALTA 3500 have been previously reported. 1 Integrating those optimized subsystems with another major subsystem improvement in the recently introduced ALTA 3700 system has allowed laser reticle writers to address the needs of maskmakers in the 180-nm and 150-nm technology nodes. This paper presents the results of a redesigned acousto-optic modulator (AOM) that addresses thermal-induced beam intensity variations, which have the potential to induce CD uniformity errors. In addition, studies on print-quality performance and throughput on mask sthat are representative of a true product show that the integrated performance of the ALTA 3700 system extends the performance of ALTA 3500 system.