It can be seen that the growth at the high deposition rate of 0.5 ML/min (Figure 4a) produced a large number of short NWs and small 3D islands. The number ratio of NWs to 3D islands is
1:2.3. The average length of the NWs and the average size of the 3D islands are about 126 nm and approximately 17 nm, respectively. At the high deposition rate, the Nutlin 3a Mn atoms have a short mean free path on the Si(110) surface and easily bind together or bind with the Si atoms to form the critical nuclei, leading to a high nucleation density. With decreasing Mn deposition rate, the number density of the NWs and 3D islands decreases significantly due to the low nucleation density. However, the average length of the NWs and the size of the 3D islands increase greatly. For example, at the low deposition rate of 0.02 ML/min (Figure 4d), the average length of the NWs and the size of the 3D islands are about 519 and 46 nm, respectively.
Meanwhile, the number ratio of NWs to 3D islands is also increased p38 MAPK inhibitor to 1:1.3, indicating that a low deposition rate can restrain the nucleation of 3D islands and favor the formation of NWs. Compared to the high deposition rate, the increase in NW length and island size at the low deposition rate can be attributed to the longer growth time because the amount of deposited Mn is the same (1 ML). Figure 4 STM images showing the influence of Mn deposition rate on the growth of NWs. Series of STM images (1,000 × 1,000 nm2) of the manganese silicide NWs and islands grown on the Si(110) surfaces at various depositing rates. (a) Approximately Mannose-binding protein-associated serine protease 0.02, (b) 0.05, (c) 0.2, and (d) 0.5 ML/min. The growth temperature and the Mn coverage were kept at 550°C
and 1 ML, respectively. Table 1 Average dimensions and number density of the NWs and 3D islands grown at different deposition rates Deposition rate (ML/min) Length of NWs (nm) Width of NWs (nm) Height of NWs (nm) Density of NWs (number/μm2) Size of 3D islands (nm) Height of 3D islands (nm) Density of 3D islands (number/μm2) 0.5 126.3 13.3 2.2 42 17.0 4.1 98 0.2 208.9 14.3 2.4 26 19.9 4.9 56 0.05 347.9 16.1 3.0 15 29.8 6.9 20 0.02 519.0 16.9 5.0 9 46.4 8.9 12 The growth temperature and Mn coverage for each deposition were kept at 550°C and 1 ML, respectively. Figure 5 is a series of STM images showing the influence of deposition time (i.e., Mn coverage) on the growth of NWs, with the temperature and deposition rate kept at 550°C and 0.2 ML/min, respectively. The statistical results of the dimensions and number density of the NWs as well as the 3D islands are listed in Table 2. It can be seen that in the short-duration range (e.g., 5 and 10 min), the NWs formed on the surface are almost uniform in width and height, and the 3D islands are almost uniform in size, as shown by Figure 5a,b.