Gettering of metal impurities in silicon by fast neutron irradiation

Some irradiated defects were introduced into p-type CZ Si by fast-neutron irradiation, they interact with oxygen in CZ Si during high temperature annealing, enhance the oxygen out-diffusion on the wafer surface and promote the precipitation of oxygen in the silicon bulk. Utilizing the combination of fast-neutron irradiation and intrinsic gettering (IG), a new excellent gettering technology only with one-step high temperature heat-treatment was invented, instead of multistep processing in conventional IG technology. With our new gettering technology, the metal impurities (Fe,Ni) on the surface of p-type <111>-oriented CZSi wafers was efficiently inhibited.