Effects of background Fe concentrations in the annealing of ion‐implanted Si into InP substrates for InP metal‐insulator‐semiconductor field‐effect transistor applications

Carrier activation for Si implants typical of metal‐insulator‐semiconductor field‐effect transistors (MISFET) channels has been investigated as a function of background Fe doping in semi‐insulating InP substrates, and different implantation temperatures and annealing procedures. A dramatic dependence of dose threshold for carrier activation on the Fe doping and on the annealing technique has been observed for the first time. A study of carrier and atomic distributions indicates that Fe redistribution is more pronounced under rapid thermal anneal (RTA) than under conventional furnace anneal (CFA). The redistribution of Fe is shown to influence the electrical characteristics of the channel‐type implants. From these results and because RTA is more suitable for integrated devices we propose an implant sequence consisting of hot implants followed by RTA to realize device‐quality layers for integrated devices. On the other hand, for discrete devices a classical furnace annealing after room‐temperature implants gives very satisfactory results.