INFLUENCE OF DIFFERENT THERMAL TREATMENT REGIMES ON THE HALL PARAMETERS AND THE LIFETIME OF CHARGE CARRIERS OF TRANSMUTATION DOPED SILICON CRYSTALS

The results of an experimental study of the Hall parameters and lifetimes of the minority charge carriers in transmutation doped n-Si < P > crystals, subjected to high-temperature annealings of different duration and cooled at different rates, are presented. It has been established that the processes of interdefect (or impurity-defect) interaction in a crystal when monotonically cooled from the annealing temperature to room temperature (at different cooling rates) do not correspond to a monotonous change in these rates. It is proved that in transmutation doped silicon crystals subjected to high-temperature annealing, the most noticeable influence on the change in Hall parameters was observed with the cooling at an intermediate rate (15 degrees C/min). It was found that after the high-temperature processing (1200 degrees C) of transmutation doped n-type silicon crystals for 2 h with the cooling rate of 15 degrees C/min, and also for 72 h and with all the cooling rates studied (1, 15 and 1000 degrees C/min), the generation of deep donor centers occurs in their volume. It was established that the highest lifetimes of minority charge carriers after high-temperature annealings will be in the samples that were cooled at the rate of 15 degrees C/min (among the series of high-temperature annealings of 2 and 72 h duration). It is shown that among all the investigated thermal treatments, the silicon crystals, annealed at 1200 degrees C during 72 h and cooled at the rate of 15 degrees C/min, have the maximum value of lifetime.