| 摘要 |
PURPOSE:To execute optimum exposure in consideration of reciprocal irregularity automatically by providing a function which can calculate a Schwartzschild's constant and the adequate value of effective energy from optimum exposure time or chip number of a chip corresponding to the exposure time. CONSTITUTION:A changer 91 is selected previously at an output from a limit discriminator 65, and a power supply 80 for a light source is set at power corresponding to an illumination stage 1. Exposure is executed by increasing or decreasing exposure time at every DELTAt between set ranges t1 and t2 under the state. The power supply 80 for the light source is set at power corresponding to an illumination stage 2, and exposure is repeated at a step DELTAt between the exposure ranges t1 and t2. A wafer 60 is exposed in succession from a first exposure chip 62 at that time, the wafer is developed and treated, the resolution, dimensional accuracy, etc. of patterns in chips are evaluated, and the best chip is obtained. The Schwartzschild's constant p and effective energy Es are memorized in registers 7, 8, and a motor 52 is driven at the best exposure time T by an amplifier 3, a 1/p multiplier 4 and an integrator 5 and exposure can be completed automatically because the changer 91 is connected to a comparator 6 on normal expsoure. |
