| 摘要 |
PURPOSE:To contrive the improvement of the position accuracy of a lithographic pattern by a method wherein marks are provided at the reflector body structure of a laser measuring system mounted on a movable pedestral and a lithographed substrate and the marks are detected by electron beams at fixed time intervals for measurement and a variation in position is fed back to a control system for correction. CONSTITUTION:The position of a mark A1 on the face perpendicular to the face of a reflecting mirror 19 and that of a mark B1 on a lithographed substrate 12 are measured by the sum of the integral value of the doppler shift of a laser beam caused by moving pedestral to position C and the conversion value of the position of a beam deflection voltage. The mark A1 is provided with variation amounts delta1, deltac, epsilon caused by an optical axis position and electrical factor for the reflecting surface of the mirror and the B1 is provided with variations deltac and epsilon, and delta2 for the reflecting surface of the mirror. Each variation amount of variation factors can not be separated in each measurement and a plurality of variation amounts during measurement is mostly controlled by an independent factor. Now, when the partition wall of the device is strictly controlled at about 1/100 deg.C to measure the variation amount between B1 and A1 and the substrate position is corrected for the A1 at fixed intervals of 10-30min, variation to the lithographic position is controlled by only the variation amount deltac+epsilon of an electron optics system and pattern position accuracy of 0.2mum or less is obtained. |
