TEST SYSTEM FOR VLSI DIGITAL CIRCUIT AND METHOD OF TESTING

摘要

ABSTRACT OF THE DISCLOSUREA method of testing the conductive state of atransistor in a semiconductor integrated circuit compris-ing the steps of applying electrical power through loadmeans to the integrated circuit, applying a clock signalto the integrated circuit, stopping the clock signal at apredetermined time period, irradiating the transistor witha focused radiation beam, and measuring change in currentapplied to the integrated circuit by correlated doublesampling whereby voltages at either end of the load meansare capacitively coupled to differential amplificationmeans measuring change in voltage at either end of theload means. Also disclosed is a test apparatus forcarrying out the method.