| 摘要 |
<p>An apparatus and method for monitoring a change of thickness of a first material with a first bandgap energy, for disposal over a second material on a wafer and having a second different bandgap energy, wherein at least one of the materials has a direct bandgap. The apparatus comprises means for changing the thickness of the first material layer; means for directing a beam of energy to impinge at an angle on to the surface and to penetrate the wafer, with the beam having an energy sufficient to pump the at least one direct bandgap material to a higher energy state; and means for detecting the induced luminescence from the at least one direct bandgap material to determine when to alter the thickness changing process. The present invention may be used to monitor both deposition and etching processes. It is particularly suited for determining the etch endpoint for III-V semiconductor materials such as GaAs and AlGaAs. <IMAGE></p> |
