Defect-Oriented Test: Effectiveness in High Volume Manufacturing

Abstract

This article describes a defect-oriented test (DOT) approach, which enables a complete physical defect-based automatic test pattern generation (ATPG) for the digital logic area of CMOS-based designs. Total critical area (TCA)-based methods are presented for the generation of needed DOT views to enable the generation of complete DOT-based patterns for detecting all cell-internal and as well all cell-external physical defects. The major aim of these new methods and patterns is to further reduce the defect rate of manufactured ICs, in addition to what is already achieved with traditional and cell-aware test (CAT) fault models. We present test results, including achieved defect rate reduction in defective parts per million (DPPM), from a large 14-nm FinFET design, including a correlation to system-level-test (SLT) fails. For a second, mature 160-nm automotive mixed-signal sensor we present high-volume production test results, again measured in DPPM, and we provide test coverage figures moving away from counting detected faults to calculating detected TCA which is reported as the chip level TCA coverage.