Modeling and characterization of a radiation sensitive p-channel transistor in a floating n-well

Characterization is made of a novel radiation sensor which is sensitive to alpha particles and protons, using computer codes and analytical models. The sensor cell consists of a p-channel transistor in a floating n-well. Cylindrically symmetric three-dimensional calculations based on the whole set of semiconductor equations are carried out in order to understand the dynamic behaviour of the sensor cell. On the other hand, a new analytical model arising from the solution of the charge continuity equation of the n-well area and a transistor model describe the main principles of the sensor and allow to determine the sensitivity and the essential sensor parameters. Furthermore, the influence of particle properties, manufacturing processes, and design parameters are studied. The results obtained by simulation are compared with measurements and are used for an improvement of sensor design and technology.