Patent ID: 6405148
Filing Date: 2002-06-11
Classification: G01R

Abstract:
An automatic semiconductor device classification system comprising:(a) a current measuring unit having: a voltage controller configured to apply a sequence of discrete output voltages between predetermined electrodes disposed on each of semiconductor devices, he discrete output voltages are gradually increasing discrete voltages, each oft the discrete output voltages is constant with regard to time the semiconductor devices are disposed in respective chip areas arranged on a surface of a semiconductor wafer; and an ammeter configured to measure corresponding discrete currents flowing between he predetermined electrodes; (b) a data memory for storing measured discrete I-V relations defined by the measured discrete current and the applied discrete output voltages, a first control voltage assigned between the predetermined electrodes, a first threshold current value assigned between the predetermined electrodes at the first control voltage, a second control voltage assigned between the predetermined electrodes which is larger than the first control voltage, and a second threshold current value assigned between the predetermined electrodes at the second control voltage, the second threshold current value is larger than the first threshold current value; and (c) the processor connected to the data memory and the current measuring unit, the processor comprising: an acquisition circuit for obtaining a first decision current value flowing between the predetermined electrodes at the first control voltage and a second decision current value flowing between the predetermined electrodes at the second control voltage using the discrete I-V relations; a comparison circuit connected to the acquisition circuit for comparing the first decision current value with the first threshold current value stored in the data memory and comparing the second decision current value with the second threshold current value stored in the data memory; and a classification circuit connected to the comparison circuit for determining an approximate I-V characteristic between the predetermined electrodes on the basis of results obtained by the comparison circuit and then performing classification according to the determination.