Implant Process Modifications for Suppressing WPE | Cypress Semiconductor
Implant Process Modifications for Suppressing WPE
The threshold voltages of CMOS transistors can vary significantly depending on their proximity to an implant well boundary. This well proximity effect (WPE) is caused by the well implant atoms that scatter laterally from the photoresist mask. From first principles of this scattering effect and detailed modeling, modifications to the mask were found that effectively suppress this induced variation in 90nm-node transistors. Consequently, circuit design can occur without having to create complex device models to account for WPE. To view more on this topic, click the download link above.