Extraction of the main current components of floating-body partially-depleted SOI devices

CMOS SOI technology is a promising candidate for mixed analog/digital low-voltage/low-power applications due to its low threshold voltage capability. Partially-depleted SOI devices are used for high-speed microprocessors (Aipperspach et al, 1999), where the speed advantage is provided by the related floating-body effects. The understanding of the electrical behavior of partially-depleted SOI devices requires a specific method for determination of the different current components flowing through the device. The drain current is the sum of the MOSFET, parasitic bipolar and impact ionization currents. Moreover, the MOSFET current depends on the internal body potential which controls the threshold voltage, resulting from a balance between impact ionization and body-source junction at high drain voltage. The aim of this paper is to describe an original method which allows the separation of the different current components of a floating-body partially-depleted SOI device.