Formation of several kinds of oxygen‐related donors around 500 °C and effects of carbon in Czochralski silicon

We have found by resistivity measurements and deep‐level transient spectroscopy that four kinds of oxygen‐related shallow donors, OD1–OD4, successively appear around 500 °C in the time region 10–106 min and carbon greatly affects their generation behavior in Czochralski silicon. The formation of OD2 and OD3 donors was enhanced by the presence of carbon, while that of OD1 and OD4 donors was retarded. The OD1 donor is identified as the so‐called thermal donor that consists of several kinds of double donors observed so far by infrared studies. The OD2 donor is a new kind of donor discovered recently by us. OD3 and OD4 donors, which were formed by very prolonged annealing around 500 °C, are suggested to have correlations with so‐called new donors normally generated above 600 °C. The origins of these oxygen‐related donors are discussed in relation to oxygen precipitation.