Parametric analysis of microprocessor SRAM through special design for test features (DFT) is used extensively by fault isolation and failure analysis engineers to find and characterize defects. Unfortunately, a growing amount of leakage on each new process is distorting these Low Yield Analysis (LYA) Testmode I-V curves, making it increasingly difficult to find and differentiate defects. The goal of this paper is to discuss the simulation and silicon results of a concept On-Die LYA (ODLYA) circuit implemented in a 65 nm CMOS process technology. ODLYA is used to curvetrace individual transistors within an SRAM cell and read out results in an automated fashion. Taking measurements on-die eliminates interconnect-dominated IR drop and leakage distortion from several levels of multiplexing. The proposed implementation enables non-destructive highspeed parametric analysis with less dependency on growing cache sizes, number of cores, and scaling process technologies.
Citation:
Benjamin M. Mauck, Vishnumohan Ravichandran, Usman Azeez Mughal, "A Design for Test Technique for Parametric Analysis of SRAM: On-Die Low Yield Analysis," itc, pp.105-113, International Test Conference 2004 (ITC'04), 2004