A Multipurpose Test Mask for Exposure Tool Characterization

Of the many facets of integrated circuit fabrication, photolithography may very well be the most important due to the number of levels required for the fabrication of sophisticated devices. Therefore it is imperative to understand the performance capabilities of an exposure tool and identify its inherent limitations. Many methods have been developed which concentrate specifically on evaluating resolution, critical dimensions or registration. Often test patterns exist which vary widely for applications with respect to steppers, IX scanning projection aligners and other IX exposure equipment. The following work is focused on the requirements of evaluating and optimizing all aspects of performance for various exposure tools with one basic design. The structures available allow this design to be compatible with all existing exposure equipment at the RIT Center for Microelectronics as well as additional tools which are likely to be available in the near future. This provides a consistent manner by which the characterization of each tool may be done as well as the ability to compare various tools directly