Transistor degradation due to radiation in a high density plasma

Extensive studies on the effects of radiation have concentrated on the performance of finished devices and ICs. Contrary to charging, radiation damage in the semiconductor manufacturing process was not considered to be of great practical importance. However, with the emergence of high density plasma tools and significant advances in charge damage protection, the radiation component share in process induced damage can be expected to increase. In this paper, we report the first comprehensive evaluation of UV effects in a commercially available HDP etch tool. Results show that UV radiation during wafer processing can result in degradation of transistor performance and reliability. A model for UV induced processes in the wafer, including hole generation in SiO₂ and electron injection into the gate oxide from Si, is discussed