MEV CARBON IMPLANTATION INTO SILICON - MICROSTRUCTURE AND ELECTRICAL-PROPERTIES

Doping effects after carbon implantation at 0.33 and 10 MeV were investigated at silicon wafers with different oxygen content. No distinct influence of the oxygen concentration on the carbon induced doping effect was found for rapid thermal annealing at 1250-degrees-C for 30 s whereas for furnace annealing at 1000-degrees-C the doping effect is higher for Czochralski-grown silicon wafers with their higher oxygen content. The gettering efficiency of a buried carbon implanted layer for additionally introduced iron atoms was investigated by deep level transient spectroscopy. Gettering sets in at a dose of 10(14) cm-2 and is completed for a carbon dose of 10(16) cm-2 for iron doses up to 10(13) cm-2. The microstructure of such a buried layer is characterised by a narrow band of dark contrast containing mainly stacking faults of the extrinsic type.