The Fundamentals of CHARM-2

Wafer Charging Monitors publishes a set of Technical Notes and Briefs to help customers understand what CHARM-2 monitor wafers comprise and how these specialized wafers can be used to identify wafer charging problems. To get a basic introduction to these topics, we recommend starting with Technical Note 1, which is entitled "The Fundamentals of CHARM-2." This Tech Note describes the three main types of EEPROM-based sensors employed by CHARM-2: 1/ potential sensors, 2/ charge-flux sensors, and 3/ UV sensors. In addition, a unipolar version of these sensors is described which can be used to detect the presence of overwriting, which can occur when charging of one polarity is followed by charging of the opposite polarity during a complex plasma or ion based process. The method used to calibrate these sensors is explained and it is shown how CHARM-2 results can be used to predict gate oxide damage. If you are not yet familiar with CHARM-2, Tech Note 1 provides the basics in a concise, easy-to-read document!