Photomask defect detection and inspection: aerial imaging and high resolution inspection strategies

Autor: Michael Ben Yishai, Sunghyun Oh, Yulian Wolff, Inpyo Kim, Changreol Kim, Aviram Tam, DaeHo Hwang
Rok vydání: 2010
Předmět:
Zdroj: SPIE Proceedings.
ISSN: 0277-786X
Popis: Advanced photomasks exploit complex patterns that show little resemblance to the target printed wafer pattern. The main mask pattern is modified by various OPC and SRAF features while further complexity is introduced as source-mask-optimization (SMO) technologies experience early adoption at leading manufacturers. The small size and irregularity of these features challenge the mask inspection process as well as the mask manufacturing process. The two major concerns for mask inspection and qualification efficacy of advanced masks are defect detection and photomask inspectability. Enhanced defect detection is critical for the overall mask manufacturing process qualification which entails characterization of the systematic deviations of the pattern. High resolution optical conditions are the optimal solution for manufacturing process qualification as well as a source of additional information for the mask qualification. Mask inspection using high resolution conditions operates on an optical image that differs from the aerial image. The high resolution image closely represents the mask plane pattern. Aerial imaging mode inspection conditions, where the optics of the inspection tool emulates the lithography manufacturing conditions in a scanner, are the most compatible imaging solution for photomask pattern development and hence mask inspectability. This is an optimal environment for performing mask printability characterization and qualification. In this paper we will compare the roles of aerial imaging and high resolution mask inspection in the mask house.
Databáze: OpenAIRE