Nanocrystalline Si-on-SiO2 samples were prepared under various processing conditions and were examined by using electron spin resonance and photoluminescence techniques. The results indicated the presence of 3 electron spin resonance centers which were associated with oxidized and annealed samples. One center was identified as being an E' defect (O vacancy). A second one was an O thermal donor which was most prevalent at low temperatures. The third one was a Si dangling-bond resonance which was more pronounced at higher temperatures. The thermal donor line exhibited a strong relationship to the 1.5eV emission which was exhibited by oxidized and annealed nanocrystalline samples. It was suggested that an oxide-related defect, which was similar to that reported in oxidized porous Si, might be the source of the optical emission.

Defect studies in as-deposited and processed nanocrystalline Si/SiO2 structures S.M.Prokes, W.E.Carlos, S.Veprek, C.Ossadnik: Physical Review B, 1998, 58[23], 15632-5