Shallow Thermal Donors in ANnealed Cz Silicon and Links ot the NL 10 EPR Spectrum: The Relevance of H, Al and N Impurites

摘要

Heat treament of Czochraski Si at -470 degree leads to the formation of shallow therma donors with ionisation energies of -36meV that ae detected by infrared absorption. The STDs produced in hydrogenated samples are shown to incorporate H atoms and give rise to a distinct set of electronic transitions. A different family of lines is detected n AL-doped samples. Such sampels also give rise to NL10 electron paramagnetic resonance spectra nad ENDOR measurements reveal the presence of H(D) or Al atoms in the dfect cores. STDN(H) and STDN(A) are produced siulatneously in hydrogneated Al-doped smal[les. Sampels pre-heated in nitrogen gas at high temperatures show yet a third set of IR electronic transitions but 14N is not detected by ENDOR. There is a suggestion that these centres incorporate a lattice vacancy. We demonstrate that there are at least three types of shallow thermal donors that have not always been distinguished by IR measurements in previous work.