Early Testable Addressable Logic (ETAL) Test Structure: Showcasing the use of an Alternate Logic Yield Learning Test Structure for Technology Development

Functional logic test structures with ATPG blocks and scan chains have been the traditional inline logic learning vehicle for technology learning and development. However, these test structures often need processing of wafers up to a higher BEOL processing level. They also need an elaborate diagnostic analysis to enable failure analysis. In this work, we showcase the use of an alternate logic test structure called the "Early Testable Addressable Logic (ETAL)" which is tested at an earlier test level and is easier to do failure analysis on. This structure can be used very effectively for yield learning at early stages of technology development as a complementary test structure to the traditional inline logic test structure.