AIMSTM EUV first insertion into the back end of the line of a mask shop: a crucial step enabling EUV production

EUV lithography is being prepared for insertion into the semiconductor production processes to continue the reduction of critical feature sizes at subsequent process nodes. To support that EUV wafer lithography development and production, the EUV photomask infrastructure similarly needs to be ready to support the shipment of EUV photomasks. EUV photomasks will require tighter process controls and tighter defect specifications to meet the requirements necessary for the wafer manufacturing insertion node. The novelty of the EUV lithography process combined with the high degree of complexity of the EUV photomask structure and process each contribute to the tightening of EUV photomask requirements, requiring accurate metrology to ensure fidelity to the photomask specifications. To fully address the industry requirements for EUV defectivity review and actinic mask qualification, ZEISS and the SUNY POLY SEMATECH EUVL Mask Infrastructure consortium have developed and commercialized the EUV aerial image metrology system, the AIMSTM EUV. The first commercial platform is already installed at a customer site and is available to support the EUV photomask production pipeline. This paper shows how the proven technology of the ZEISS aerial image system implemented into the AIMSTM EUV platform supports EUV photomask production in the back end of the line of Intel photomask manufacturing shop. Alongside with describing the essential development phases of the platform at customer site, examples of the reproducible measurement quality, as well as stability of the imaging fidelity of the system in production will be shown. In addition, the system output together with the experience on uptime and availability of the AIMSTM EUV platform in production is presented.