| 摘要 |
<p>PROBLEM TO BE SOLVED: To make good positioning control of wafer executable by updating the light quantity correcting value for every alignment of the wafer to deal with the change of light receiving amount. SOLUTION: The method for measuring a wafer with an optical linear sensor comprises a wafer conveyance detecting step of detecting no conveyance of the wafer into an alignment chamber 30, a function correcting step of correcting a function for relating at least two of a light receiving amount, the light receiving width and the light emitting amount of the sensor from the receiving amount of the linear sensor 700 in the state where the wafer is not conveyed, a light receiving amount measuring step of measuring the receiving amount of the conveyed wafer, and a measuring step of measuring a length of the wafer crossing a light receiver according to the corrected function. Thus, in the case of aligning, a new light quantity correcting value can be always used for the detected value of the sensor, and hence an influence of a change of the detected value of the sensor with a dirt of a measuring window can be prevented.</p> |
