日本大学生産工学部　生産工学部研究報告A51-2

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─ 6 ─jections at 25 eV. Figure 9 shows the net erosion yields as a functions of the injection dose in the cases of (a) N atom and (b) NH3 molecule injections. In the contrast to Figs.3 and 5, at the beginning of the injections, the substrate is strongly sput-tered due to the higher injection energy (Figs.9 and 8). More-over, in the latter of injections, after once the YN saturates (~ 28.0 × 1015/cm2 injection dose) the YC again increases for N injections (Fig.9 (a)), however, for NH3 injections, the incre-ment of YC is suppressed due to a large amount of injected hy-drogen atoms. It is speculated that many of incident N atoms make chemical bonds with H atoms and hardly form CN layer. These tendencies are similar to the cases of N and NH3 injec-tions at 25 eV.Comparing Figs.4 and 6 and, Figs.10 and 11 it can be seen that qualitatively similar CN layers are formed while the line shapes of number of N atoms in the substrate (Figs.4 and 10) and chemical bonds, CN=1, 1.5, and 2 (Figs.6 and 11) distri-butions are roughly changed from triangular to trapezoidal. These facts indicate that the formed CN layers at 50 eV have somewhat homogeneous distribution of N atoms than that of formed at 25 eV. Figure 8 shows dose dependence of the sput-tering yields of the subsrate carbon atoms for N and NH3 in-jections. In the initial stage of the injection, the yields show almost same dose dependences and amplitudes for both injec-tions. With growing the injection dose, however, the sputter-ing yield for N injections is clearly larger than those of NH3 injections. In contrast, on averagely, the sputtering yields shown in Fig.5 did not show plain increment when the injec-Fig.9: The net erosin yields Yα (α =C, H, or N atoms) vs. injection dose in the case of (a) N and (b) NH3 injections. The injectin energy is 50 eV and its direction is normal to the surface.(a)09.619.228.838.44857.667.2−101dose[1015 / cm2]sdleiynoisoretenN injections (50eV)YHYCYN(b)09.619.228.838.44857.667.2−101dose[1015 / cm2]sdleiynoisoretenNH3 injections (50eV)YHYCYNFig.11: The densities of bond number of carbon-nitrogen bonds (NCN=x, x = 1, 1.5, or 2) per unit volume vs. the height of the substrate for (a) N and (b) NH3 injections. In the gures, we denote the densities of bond number as “bond densities” for simplicity.(a)00.91.82.73.64.5020406080height [nm]mn[seitisneddnob−3]NCN=1NCN=1.5NCN=2N injections (50ev)(b)00.91.82.73.64.5020406080height [nm]mn[seitisneddnob−3]NCN=1NCN=1.5NCN=2NH3 injections (50ev)Fig.10: The densities of particle number of each atom (Nα, α =C, N, or H) per unit volume vs. the height of the substrate, for (a) N and (b) NH3 injections.(a)00.91.82.73.64.504080NCNHheight [nm]mn[seitisnedrebmun−3]NNN injections (50ev)(b)00.91.82.73.64.504080NCNHheight [nm]mn[seitisnedrebmun−3]NNNH3 injections (50ev)