Defect characterization in floating body transistors using a single pulse charge pumping method

Abstract

Field-effect transistors on a floating body channel have been used for a range of applications, such as three-dimensional nand flash and high-performance devices on silicon-on-insulator wafers. Conventional techniques to characterize the defect states cannot be implemented because those transistors do not have body contacts. A single-pulse charge pumping (SPCP) method was introduced to characterize the defect state distribution of the floating body transistors. The results extracted from the SPCP method on the three-terminal transistors (without body contact) agreed well with those from a conventional charge pumping method or SPCP on four-terminal transistors (with body contact). The validity of the SPCP measurement of the floating body devices was demonstrated by monitoring the increase in the defect state of the three-terminal poly-Si transistors density during the bias stress test. The SPCP method could detect the defect states of floating body transistors with high resolution.