Reliability evaluation of thin gate oxide using a flat capacitor test structure

A test structure with very low-level current measurement technique (minimum detectable current is 5/spl times/10/sup -17/ A) has been developed and is used for measuring very small change of leakage current caused by trapping and detrapping of electrons or holes. The present technique to measure very low level current of aA order is very useful for accurate evaluation of retention characteristics and stress induced degradation of gate oxide.