Lifetime control by palladium diffusion in silicon

This paper will discuss the use of palladium for the control of lifetime in silicon power devices. It is shown that palladium has the advantage over platinum of lower solubility (by a factor of 20-50). As a result, greater process control can be achieved for lifetimes in the range that is desireable for power rectifiers and thyristors (0.1 to 1 µsec). Experiments, conducted on diodes made with both p- and n-type silicon, are used to establish the dominant lifetime controlling level in each case, together with its capture parameters. Finally, an assessment is made of the advantages and disadvantages of palladium doping for semiconductor power devices.