Monitoring interface traps by DCIV method

DCIV method is demonstrated as a production monitoring tool for process-residue interface traps. The high sensitivity of the methodology attained from forward-biasing a p-n junction allows routine detection of as few as 100 active interface traps in small area MOS transistors. Examples are given for MOST's from five different sub-half-micron production technologies. The body recombination current shows peaks around the intrinsic surface condition whose amplitude is proportional to the number of active interface traps in the mid-channel region. The variation of the peak amplitude with the forward bias voltage follows exactly the single-energy level formula, from which the interface-trap energy level can be determined to a few tenths of a kT accuracy.