| 摘要 |
PURPOSE:To enable to perform an excellent focal control over the whole area of the deflection field by a method wherein a deflection correcting device is provided in a deflection control system, the correcting amount of deflection is determined in proportion to the amount of deflection of the electron beam, and based on this decision, the amount of deflection of the deflection control system is corrected. CONSTITUTION:The digital signals X and Y which designate the positions of deflection repectively, are recieved by D/A transducers 1 and 1', and these outputs are given respectively to the X and Y deflectors 11 and 11', which constitute an electron beam exposing device, through the intermediaries of rotation correcting circuits 2, 2' and deflection amplifiers 3, 3'. Also, below these deflectors 11 and 11', the last lens 12, a correcting coil 13 and the last iris diaphragm 14 are provided, and an exposure is given to a sample 15 to be exposed. In this constitution, the output of the dynamic focus circuit 4, which is connected to the transducer 1' and the circuit 2', is given to the correcting coil 13 through the intermediary of an amplifier 5, and in addition to the above, an arithmetic circuit 6 is provided between the circuits 2, 2' and a circuit 4, and corrects the rotation of the deflection field involving the dynamic focus function. |
