Characterization of leakage current in buried-oxide SOI transistors

The junction leakage current of MOSFETs built in oxygen-implanted silicon-on-insulator (SOI) substrates has been measured as a function of terminal voltages and temperature. Analysis of the results indicates that the physical mechanism causing the high junction leakage current, typically seen in SOI MOSFETs, is field-enhanced emission of carriers through traps near the buried-oxide/silicon interface. These traps are a consequence of the incorporation of metal impurities during oxygen implantation. The effects of conventional gettering techniques, oxygen dose, and control of metal contamination by modification of implanter design on leakage current are discussed.<
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