| 摘要 |
PURPOSE:To stably detect a foreign body of submicron order stuck on a substrate with a circuit pattern. CONSTITUTION:The foreign body inspection device consists of a detection optical system 4 which converges scattered light generated by oblique lighting 2 through an optical system 41 with a >=0.4 numerical aperture and cuts off diffracted light from the circuit pattern by a spatial filter 44 provided on a Fourier transformation surface to form an image on a detector 51, a circuit 113 which corrects the detected value of a detector according to a lighting irregularity, a circuit which finds the addition value of detected values of 2X2 picture elements, a circuit 114 which finds the largest value among four addition values shifted by one picture element in four circumferential directions of a detector picture element, and a circuit 112 which stores the detection result in a memory divided into blocks of hundreds of picture elements on the sample. |
