| 摘要 |
An ellipsometer system for measuring the thickness of a film as it is being deposited on a substrate in a furnace. The system includes means for projecting a coherent beam through a window in the furnace. There are two reflective surfaces in the furnace on which films are being deposited which reflect the beam through an exit window in the furnace to a sensor located outside of the furnace. The drawings show a furnace (135) containing main substrates (140) and measuring substrates (136, 138). All the substrates are equally and simultaneously coded. A laser source (132) directs a monochromatic beam onto substrate (136) where it is reflected to substrate (138) and thereby out of the furnace. The receiver unit (144) contains a Wollaston prism which splits the light beam into Ip, Is beams respectiverly polarised in perpendicular planes. The Ip, Is beams are detected by suitable detectors in the unit (144) and two electrical signals Ip, Is, generates. The Ip, Is signals, together with an Io electrical signal representing the intensity of the original laser beam, are fed to an interface (146). The interface (146) provides a signal representing the relative magnitudes of the Ip, Is, beams to a data processor unit (148). The data processor unit (148) operates according to an alogirthm to convert the Ip, Is values to film parameters. The output of unit (148) controls the furnace controller.
|
