Combined lifetime killing by platinum and fast light ions in silicon power diode : thermal stability of introduced radiation defects
The influence of combined lifetime killing by platinum in-diffusion and fast light ion irradiation on generation and stability of introduced radiation defects was investigated in the low-doped n-type float-zone oxygen rich silicon forming the base of power pnn diodes. Different concentrations of platinum substitutionals were introduced by platinum implantation and subsequent annealing at temperatures ranging from 725 to 900°C. Diodes were then irradiated with 1.8 MeV protons or 5 MeV alphas to fluences ranging from 5x10 to 1x10 cm. The influence of platinum doping on introduction rates of dominant radiation defects and their thermal stability during subsequent isochronal annealing was investigated by deep-level transient spectroscopy. Results show that the presence of platinum atoms significantly influences introduction rates of dominant recombination centers introduced both by hydrogen and helium irradiation (vacancy-oxygen pairs, divacancies and VOH complexes). Simultaneously, temperature stability of vacancy-oxygen pairs and divacancies decreases of up to 150°C. In both cases, these effects are proportional to platinum concentration introduced into diodes.
High-power P-i-N diode with the local lifetime control based on the proximity gettering of platinum
We demonstrate for the first time a high-power P-i-N diode with local lifetime control using the proximity gettering of platinum in the FZ silicon. The region of maximal damage resulting from the low-dose helium implantation was decorated by substitutional platinum that diffused from the PtSi anode contact at low temperature (700/spl deg/C) through the P/sup +/-P anode doping at the distance of 70 /spl mu/m. The diodes show very low forward voltage drop with negative temperature coefficient and very low leakage current even at elevated temperatures while keeping the major advantages of the ion irradiated devices like low turn-off losses and soft recovery.
On the role of uncontrolled sinks in silicon under irradiation
Ces sources incontrolees jouent un role negligeable dans la formation de defauts de radiation par rapport aux principales impuretes technologiques dans le silicium commercial tres pur. Ces sources peuvent surtout affecter la formation de defauts de radiation a travers l'annihilation indirecte des composantes des paires de Frenkel