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In this work we perform a systematic study of the dissolution of a dislocation loop layer under the influence of inert SiO2/Si and nitrogen-rich SiO2/Si interfaces. The composition of the dislocation loop layer was just after its formation 10%–20% Frank dislocation loops and 90%–80% perfect prismatic loops. During subsequent inert (N2) ambient annealing the differences of the kinetics between the two loop populations have been studied as a function of the interface type. It has been shown that during the nonconservative Ostwald ripening process the defect band loses interstitials mainly due to the dissolution of perfect prismatic loops, while Frank loops remain almost unaffected by the presence of both interfaces. In parallel a competition between the interface and the population of Frank loops in absorbing the interstitials released by the prismatic loops took place. The nitrogen-rich SiO2/Si interface has been proved in general a less effective interstitial sink than the common one and under specific annealing conditions less effective even than the small Frank loops population. [ABSTRACT FROM AUTHOR]

In a previous work [Skarlatos et al., J. Appl. Phys. 93, 1832 (2003)] we investigated the influence of implantation energy on oxide growth and defect formation in nitrogen-implanted silicon substrates. It was shown that as the implantation energy decreases from medium to very low values the oxide reduction decreases. This was attributed to nitrogen out-diffusion, which is more effective when nitrogen is placed closer to the silicon surface. On the other hand very low implantation energy avoids the formation of dislocation loops in the silicon substrate, a key point for modern devices performance. In this second part we compare the nitrogen distribution and electrical properties of ultrathin (25–30 Å) oxides grown under the same oxidation conditions on very low (3 keV) and medium (25 keV) energy nitrogen-implantated silicon. Nitrogen distribution measurements show that a lower content of nitrogen remains within the oxides formed using 3 keV energy as compared to the 25 keV case supporting the results of the first part of this work. So at very low implantation energy the same oxide thickness is obtained increasing the implantation dose. On the other hand oxides formed through very low energy implants show superior electrical properties in terms of surface states and leakage currents due to the lower damage induced in the silicon substrate. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Abstract: In the present work we perform a systematic study of oxidation of very low energy nitrogen-implanted strained-silicon in terms of oxide growth, structural characterization of the implanted strained-silicon substrate and electrical properties of the ultra thin oxides as a function of the substrate strain level. Low energy (3keV) nitrogen (N2 +) implantation was performed in strained-Si/SiGe/Si substrates of various strain levels and oxidations were carried out for different times at 850°C. It has been found that nitrogen implantation efficiently blocks silicon oxidation, independently of the strain level of the substrate. TEM analysis revealed the full absence of extended defects in the strained-silicon substrate after the thermal treatments. The grown oxides exhibit very good electrical properties in terms of interface trap densities and leakage currents. [Copyright &y& Elsevier]

Metal-oxide-semiconductor tunnel diodes with gate oxides, in the range of 2.5-3.5 nm, grown either on 25 or 3 keV nitrogen-implanted Si substrates at (0.3 or 1) × 10[SUP15] cm[SUP-2] dose, respectively, are investigated. The dependence of N[SUP+, SUB2] ion implant energy on the electrical quality of the growing are investigated. The dependence of N[SUB2] oxide layers is studied through capacitance, equivalent parallel conductance, and gate current measurements. Superior electrical characteristics in terms of interface state trap density, leakage current, and breakdown fields are found for oxides obtained through 3 keV nitrogen implants. These findings together with the full absence of any extended defect in the silicon substrate make the low-energy nitrogen implantation technique an attractive option for reproducible low-cost growth of nanometer-thick gate oxides. [ABSTRACT FROM AUTHOR]

In this work we examine the structural and electrical properties including the memory performance of Al 2 O 3 /Si 3 N 4 /SiO 2 dielectric stacks implanted with low-energy nitrogen ions and subsequently thermal annealed at 850 or 1050 °C for 15 min. X-ray photoelectron spectroscopy reveals that the concentration and the chemical state of the nitrogen atoms within the Al 2 O 3 layer depends on the post-implantation annealing (PIA) temperature. Memory testing, performed on platinum gate capacitors, shows that charge retention of the programmed states is significantly improved for the high-temperature PIA samples as compared to the non-implanted samples. While such an improvement is not detected for the low-temperature PIA samples, the latter exhibit enhanced hole charging and thus, increased erase efficiency. Overall, our results suggest that the transport properties which control the erase and the retention characteristics of the blocking Al 2 O 3 layer can be tailored by nitrogen implantation and the PIA conditions and can be used for memory performance optimization. [ABSTRACT FROM AUTHOR]