Patent ID: 6445197
Filing Date: 2002-09-03
Classification: G01N,G01R,H01J

Abstract:
An electron beam tester for testing an electric component, comprising:a drive circuit which supplies a signal to the electric component; an electron gun which causes to emanate a secondary electron from the electric component by irradiating the electron beam to a predetermined position of the electric component; a detector which measures an amount of the secondary electron emanated from the electric component and outputs a signal representing the amount of the secondary electron, the outputted signal comprising a first phase including a substantially constant voltage and a second phase which follows the first phase and includes a non-constant voltage; a first variation detecting unit which calculates a signal outputted by the detector and outputs a first distributed value indicating fluctuation of a voltage of the outputted signal, the first variation detecting unit calculating out the first distributed value at a particular data of the outputted signal in the first phase; a second variation detecting unit which calculates the outputted signal and the first distributed value, calculates out a second distributed value indicating fluctuation of a voltage of signal outputted by the detector, and outputs a third distributed value by subtracting the first distributed value from the second distributed value, the second variation detecting unit calculating out the second distributed value at a particular data of the outputted signal in the second phase; and a voltage variation amount detecting unit which outputs a voltage with a phase data corresponding to the third distributed value.