Noncontact internal waveform measurements with picosecond time resolution on a 0.5- mu m CMOS SRAM

Waveform measurements at the internal nodes of a 0.5- mu m CMOS SRAM (static random-access memory), performed at room temperature and at low temperature (80 K), are presented. These measurements yield detailed information on the internal operation of the circuit, and, more precisely, on the delays whose sum constitutes the access time in this high-speed memory circuit. The waveforms are measured in a noncontact, nonintrusive fashion with a recently developed ultrafast electron-beam prober, the picosecond photoelectron scanning electron microscope.<>