Yield Learning and Process Optimization on 65-nm CMOS Technology Accelerated by the Use of Short Flow Test Die

Short loop test flows have been commonly used in back-end-of-line (BEOL) interconnect process development to speed up learning rates and improve yields. This paper presents case studies on the expanded use of short loop test chips to the shallow trench isolation and gate and premetal dielectric/contact loops of a 65-nm process technology in addition to the BEOL. These test chips have been used to quickly identify and eliminate random and systematic defect mechanisms and generate a robust process flow, thus accelerating the rate of yield learning.