| 摘要 |
PURPOSE: An apparatus for detecting the intensity of a semiconductor stepper is provided to prevent an exposure defect like an exposure time delay or uniformity defect of critical dimension(CD), by performing an exposure process after an optic is immediately replaced when a detected illumination value is lower than a reference value. CONSTITUTION: Dichromatic mirrors are installed to reflect a part of a beam on the lower portion of the first image shifter, a wedge unit, the second image shifter and a glass plate top, respectively. Optical sensors are respectively connected to the dichromatic mirrors to detect the quantity of the beam reflected from the dichromatic mirrors. A calculator converts the quantity of the beam detected by the optical sensors to an illumination value.
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