Hydrogen redistribution and enhanced thermal donor formation at post implantation annealing of p-type hydrogen implanted Czochralski silicon

The hydrogen redistribution and the enhanced conversion of the region near the surface of hydrogen implanted p-type Czochralski (Cz) silicon wafers into n-type by thermal donor (TD) formation at low-temperature (450°C) post-implantation annealing have been investigated. For comparison low-temperature (260°C) RF hydrogen plasma treated Cz Si with subsequent annealing at 450°C was studied, too. Spreading resistance probe (SRP) analysis and secondary ion mass spectrometry (SIMS) were used for the samples characterization. It is shown that the hydrogen redistribution and hydrogen enhanced thermal donor formation in hydrogen implanted or hydrogen plasma treated p-type Cz Si leads to the formation of deep p–n junctions after 450°C annealing. The buried defect layer in hydrogen implanted Cz Si samples acts as an effective getter for hydrogen and therefore a delay in the formation of deep p–n junctions was observed as compared to hydrogen plasma treated samples with subsequent annealing at 450°C.