Lifetime control in silicon power P-i-N diode by ion irradiation: Suppression of undesired leakage
The irradiation with high-energy (7.35MeV) protons through a set of energy degraders was used to suppress leakage of the silicon power diodes subjected to local lifetime control. The aim was to modify the profile of recombination centers and to reduce production of vacancy complexes. The high-energy proton irradiation was compared with standard local lifetime killing by high-energy alphas. Recombination centers arising from irradiation were characterized after irradiation and subsequent annealing at 220 and 350C by deep level transient spectroscopy and IV profiling. Static and dynamic parameters of irradiated diodes were also measured and compared. Results show that the applied irradiation with protons provides 310 times lower leakage compared to standard alphas for equivalent reduction of the reverse recovery current maximum. On the other hand, the excessive formation of hydrogen donors at high proton fluences and their diffusion during annealing at 350 decreases diode blocking capability.
lifetime control silicon irradiation protons power diodes alphas