A Procedure for the Evaluation and Failure Analysis of M.O.S. Memory Circuits using the Scanning Electron Microscope in Potential Contrast Mode

Methods of evaluation of M.O.S. memories with the S.E.M. in voltage contrast mode with emphasis on surface potential measurement techniques were discussed. An HF 1101 - 256 bit RAM was used as the test vehicle and techniques for threshold voltage measurements on any M.O.S. transistor in the circuit was established. Voltage contrast images of patterns written into the memory and a stroboscopic method of analysing the device under dynamic conditions were reported.