| 摘要 |
PURPOSE:To improve the correcting accuracy of focusing characteristic corresponding to miniaturization of a pattern and an increase in an exposure region by providing illuminance distribution measuring means, focusing characteristic calculating means and focusing characteristic correcting means. CONSTITUTION:An image face on a wafer W of reticle R is divided to obtain illuminance distribution of each part (10A). Heat accumulation for each divided image face is calculated, and focusing characteristic and variation amount of each part is obtained based thereon. A controller 10 obtains information of an illuminance sensor 11, a shutter control unit 2B, a blind 6A, a pressure regulator 12 based on the results to correct the focusing characteristic. Variation in the focusing characteristic when a projecting optical system with intensity distribution of the illuminated light does not uniformly absorb the light is calculated as the distribution of temperature rise in a lens face to predict the variation. The lens face is divided corresponding to the divided image face, the light absorption and the exchange of the heat are calculated, and the temperature rise of the part is obtained. When parameters are regulated to match the actual focusing characteristic change, the distribution of the focusing characteristic change in the image face can be predicted to improve the focusing characteristic. |
