| 摘要 |
PURPOSE:To receive diffracted light always at the same conditions even if an optical axis of diffracted light varies and to thereby accurately monitor development proceeding state. CONSTITUTION:The title device is provided with an optical system which a development monitor point 1a with laser beams on a pattern surface of an original film 1 wherein a pattern is exposed, the 0-order light detection part 2 and the first order detection part 3 for receiving the 0-order diffracted light and the first order diffracted light from the development monitor point 1a separately and a diffracted light ratio calculation part 10 for calculating diffracted light ratio between the 0-order diffracted light and the first order diffracted light based on diffracted light detection signals a, b output from each of the light detection parts 2, 3. An oval surface mirror 4 which reflects primary diffracted light L1 of laser beam L toward the first order light detection part 3 is provided between the development monitor point 1a and the first order light detection part 3a. |
