Patent ID: 7439504

Claim:
A pattern inspection apparatus comprising: a stage for mounting a specimen on which a pattern is formed; a charged particle beam irradiating device for irradiating a charged particle beam on a surface of the specimen; a retarding voltage source for applying retarding voltages to the stage so as to control an acceleration voltage of the charged particle beam incident on the specimen by the irradiating; an E×B for deflecting secondary charged particles emanated from the surface of the specimen by the irradiation of the charged particle beam by the charged particle beam irradiating device; a detector provided with a plurality of sensors for simultaneously detecting, with a plurality of sensors, secondary charged particles deflected by the E×B, said detector further including logic for enabling predetermined decision making capabilities; said E×B deflecting the secondary charged particles such that the secondary charged particles form a spot whose area is as large as the area of the detector with the plurality of sensors at most; a reflector for colliding the secondary charged particles prior to forming the spot; a plurality of preamplifiers for amplifying each of signals outputted from each of said sensors; a signal combining circuit for switching outputs of the preamplifiers depending on the retarding voltages an A/D converter for adding and converting each signal amplified by each preamplifier to digital images; and a defect detector detecting a defect of the pattern formed on the specimen by processing the digital images obtained from the A/D converter.