Investigation of DC hot-carrier degradation at elevated temperatures for n-channel metal-oxide-semiconductor field-effect-transistor of 0.13 μm technology

In this study, n-channel metal-oxide-semiconductor field-effect transistors (nMOSFETs) having 20 and 32 angstrom gate oxide thicknesses of 0.13 mu m technology were used to investigate DC hot-carrier reliability at elevated temperatures up to 125 degrees C. The research also focused on the degradation of analog properties after hot-carrier injection. On the basis of the results of experiments, the hot-carrier degradation of I-d.op (drain current defined on the basis of analog applications) is found to be the worst case among those of three types of drain current from room temperature to 125 degrees C. This result should provide valuable insight to analog circuit designers. As to the reverse temperature effect, the substrate current (I-b) commonly accepted as the parameter for,monitoring the drain-avalanche-hot-carrier (DAHC) effect should be modified since the drain current (I-d) degradation and I-b variations versus temperature have different trends. For the devices having a gate oxide thinner than 20 angstrom, we suggest that the worst condition in considering hot-carrier reliability should be placed at elevated temperatures.