| 摘要 |
<p>Apparatus for monitoring a thickness of a silicon wafer with a highly-doped layer at least at a backside of the silicon wafer is provided. The apparatus has a source configured to emit coherent light of multiple wavelengths. Moreover, the apparatus comprises a measuring head configured to be contactlessly positioned adjacent the silicon wafer and configured to illuminate at least a portion of the silicon wafer with the coherent light and to receive at least a portion of radiation reflected by the silicon wafer. Additionally, the apparatus comprises a spectrometer, a beam splitter and an evaluation device. The evaluation device is configured to determine a thickness of the silicon wafer by analyzing the radiation reflected by the silicon wafer by an optical coherence tomography process. The coherent light is emitted multiple wavelengths in a bandwidth b around a central wavelength wc.</p> |
