On-chip sampling sensors for high frequency signals measurement:evolution and improvements

Abstract

Due to increasing speed and complexity, integrated circuits (ICs) are faced with severe parasitic problems: signal glitch, supply, crosstalk induced delay, substrate coupling. Various measurement techniques have been developed in order to observe these effects. Off-chip methodologies such as E-beam sampling, direct probing or S-parameters, allow to probe some parasitic phenomena, but they have strong limitations in term of bandwidth, invasive probes, complex setup or cost. In this paper, an overview of different on-chip measurement systems is presented. An on-chip sampling technique is detailed and we describe the applications for which this sensor has succeeded to provide accurate measurements. Sensor performances are compared for four CMOS technologies (0.7/spl mu/m, 0.35/spl mu/m, 0.18/spl mu/m and 90nm). In the last part, we present an improved sensor which measures all parasitic phenomena in the full supply range.