Surface inspecting apparatus and method for calibrating same

摘要

While an illumination optical system is irradiating the surface of a contaminated standard wafer with illumination light, this illumination light is scanned over the surface of the contaminated standard wafer, then detectors of a detection optical system each detect the light scattered from the surface of the contaminated standard wafer, next a predefined reference value in addition to detection results on the scattered light is used to calculate a compensation parameter “Comp” for detection sensitivity correction of photomultiplier tubes of the detectors, and the compensation parameter “Comp” is separated into a time-varying deterioration parameter “P”, an optical characteristics parameter “Opt”, and a sensor characteristics parameter “Lr”, and correspondingly managed. This makes is easy to calibrate the detection sensitivity.

主权项

1. A surface inspecting apparatus comprising:
a light unit that irradiates with illumination light a surface of a body to be inspected; a scanner that scans the light irradiated from the light unit over the surface of the to-be-inspected body; at least one light detector that detects the light scattered from the surface of the body to be inspected; a processor configured to:
use a predefined reference value, as well as a detection result on measuring light incident upon the light detector from a measuring-light generator that generates the measuring light that serves as a reference for measuring detection sensitivity of the light detector, to compute a sensitivity correction value for correcting the detection sensitivity of the light detector;separate the sensitivity correction value into element parameters corresponding to a plurality of factors influential upon detection sensitivity of the surface inspecting apparatus; and memory, associated with the processor, for storing the element parameters obtained from the separation by the processor.