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It has been established by 1H NMR spectra measurements of the Si-SiO2 system composed on n- and p-type Si samples,that the line width of the chemical shift of protons of the n-type samples is broader that of the p-type ones.The extent goes ap with the extent to wich the movement of adsorbed molecules is hindered. One possible reason for that can be the strength of the magnetic interaction with the paramagnetic impurities of the adsorbent.In the present work set of experiments to investigate the effect is performed. Hydrogen content in SiO2 was varied by oxidation ambient composition and by SiH4 decomposition in NH3 ambient up to Si3N4 formation of SiO2. Hydrogen does not penetrate trough Si3N4 and it provide
its separation.After nitride deposition the difference in hydrogen content between n- and p- type wafers increases.To evaluate the hydrogen redistribution that occurs in the structures on p- type samples after nitride deposition we have recorded 1H NMR spectra of p-type wafwers before and after Si3N4 deposition. A small change in relative intensities of the resonance lines indicates that after Si3N4
deposition the number of Si-H bonds increases whereas the number of Si-OH bonds decreases. The Si-H bonds density increase my be connected with the interaction
between hydrogen and vacancies at the interface due to the spin injection. It has
been established that this effect depended on the strength of the magnetic field,
on the angle between the magnetic field and the sample, on the storage time in
magnetic fields and samples preparation condition. To evaluate the contribution of
different hydrogen species, its distribution in SiO2 on n- and p-type samples, the
influence of the ions drift in SiO2 on n- and p-type samples in electrical field at elevated temperature on the charge value in SiO2 was investigated.It has been established that in MNOS structure on p-type Si the treatment brings about the increase of the charge value, that is greater than in MNOS structures on n-type
samples and hence,the content of weak bonded hydrogen in is different. |