Low-frequency noise degradation caused by STI interface effects in SOI-MOSFETs

The low-frequency noise characteristics of SOI MOSFETs with shallow trench isolation (STI) structure are investigated for various device sizes with th ree different gate shapes. Devices with channel region butted to the STI sh ow the increase of low-frequency noise as the channel width is reduced. In comparison, the devices without the STI butted to channel region show much less increasing noise power spectral density with the channel width. From t he charge pumping and noise measurement results, the interface-state genera ted by the STI process is identified as the cause of these anomalous phenom ena.