Ionizing radiation damage near CMOS transistor channel edges

Enhanced radiation damage near channel edges of n- and p-channel MOS transistors has been observed from measurements of channel resistance and gate-induced drain leakage current. Good correlation between these two types of measurements has been established. The degree of such edge effects has been found to depend strongly on the process technology. In some cases, the radiation damage near the edge plays a major role in the total device degradation, and it becomes more important as the device size reduces. A comparison has been made among transistors fabricated with standard, fluorinated, and radiation-hardened oxides. The results suggest that it is possible to minimize the radiation-induced edge effects by the use of appropriate process conditions.