Electron beam testing of integrated circuits using a picosecond photoelectron scanning electron microscope

A scanning electron microscope which uses an ultrashort pulsed laser/photocathode combination as an electron source produces electron pulses of about 1 ps in duration at a 100 MHz repetition rate. By using this instrument in the stroboscopic voltage contrast mode we have performed waveform measurements at the internal nodes of high speed silicon integrated circuits at room and at liquid nitrogen temperature, and studied the propagation of ultrafast electrical transients on various interconnection structures.