Radic: A standard-cell-based sensor for on-chip aging and flip-flop metastability measurements

As process technology further scales, aging, noise and variations in integrated circuits (ICs) and systems become a major challenge to both the semiconductor and EDA industries, since a significantly increased mismatch is emerging between modeled and actual silicon behavior. Therefore, the addition of accurate and low-cost on-chip sensors is of great value to reduce the mismatch. This paper presents a standard-cell-based, novel, and accurate sensor for reliability analysis of digital ICs (Radic), in order to better understand the characteristics of gate/path aging and process variations' impact on timing performance. The Radic sensor performs aging, flip-flop (FF) metastability window and variation measurements on-chip. This sensor has been fabricated in a floating gate Freescale SOC in very advanced technology. The measurement results demonstrate that the resolution is better than 0.1ps, and the accuracy is kept throughout aging/process variation. Furthermore, reliability and FF metastability measurements are performed using the proposed sensor. The measurement results agree with the existing models.