Degradation of I/O devices due to ESD-induced dislocations

Degradation in leakage current characteristics of I/O circuits due to ESD events has been studied. TEM observations revealed the generation of crystalline defects in the silicon substrate such as dislocations induced by ESD stress which increased the reverse leakage current level of the p-n junctions in the I/O circuits. We found that current crowding occurs in the silicon surface region during an ESD event resulting in defect generation. We also show that optimal impurity profiles for protection devices can avoid such current crowding and hence the leakage current degradation.<>