Back-channel-type scanning charge pumping method for characterization of interface traps in silicon-on-insulator wafer

A scanning charge pumping method using a back channel is proposed for the characterization of interface traps in a silicon-on-insulator (SOI) wafer. In this method, a contactless gate electrode is used instead of the permanent gate electrode of normal metal–oxide–semiconductor transistors, allowing the interface trap density of SOI wafers to be mapped. A preliminary study is performed using a sample device with many permanent gate electrodes fabricated on an oxidized SOI wafer. The results demonstrate that the back-channel-type scanning charge pumping method is effective in characterizing interface trap density and is potentially applicable to SOI wafer inspection.