| 摘要 |
PURPOSE:To compensate a fluctuation in focussing positions and an error in reduction magnification by a method wherein the atmospheric pressure within an exposure optical system is measured to control the relative optimum positions of an original picture pattern, exposed element and reduction lens making reference to the measured values of atmospheric pressure. CONSTITUTION:When the atmospheric pressure within an exposure optical system is measured by an atmospheric pressure senser 17 assuming the reference atmospheric pressure taken into a processor as Po, measured atmospheric pressure as P, reference position of original picture as ZRo, reference position of semiconductor wafer as ZWo, the optimum position of negative ZR wherein both focussing position and reduction ratio can be compensated within the exposure system in case of any fluctuation in atmospheric pressure as well as the optimum position of semiconductor wafer ZW are calculated by the expression as follows, i.e., ZR=KR (P-Po)+ZRo, ZW=KW(P-Po)+ZWo, where KR, KW are compensation coefficients assumed as theoretical values or experimental values specified in the exposure optical system. Thus, within a controller 13, a semiconductor wafer 6 is inched in the direction of optical axis of a reduction lens making reflence to ZW while within another controller 16, a negative substrate 3 is inched in the direction of optical axis making refence to ZR. Through these procedures, a fluctuation in the exposure optical characteristics resultant from a fluctuation in atomospheric pressure within the projection exposure optical system can be automatically compensated. |
