This can develop into an undesirable covering, making the processing in this area is affected.
The particles can prevent the etching or the precipitation of layers. This can lead to malfunctioning such as short-circuits or missing electrical joints between conductors. The particle inspector of EVT analyses the surface of the wafer concerning dust and other particles.
The measuring principle is based on a laser line, which scans the wafer. The wafer is reflecting scattered light and this can with the help of photodiodes be changed into an electrical signal. This signal is then compared with a previously saved reference value. The software recognises even the slightest discrepancy and can send an evaluation of the wafer as ‘good’ or ‘bad’.
The EyeVision software is also very easy-to-handle and the particle inspection can be adjusted easily in the graphical user interface.