Effects of deposition angle in low-temperature metal (100) epitaxial growth

The effects of oblique incidence on the surface roughness in low-temperature $\mathrm{Cu}∕\mathrm{Cu}\left(100\right)$ epitaxial growth are investigated via kinetic Monte Carlo simulations, which include the effects of shadowing as well as short-range and long-range attraction. While the effects of deposition angle are found to be relatively weak at $200\mathrm{K}$, at a slightly lower temperature $\left(160\mathrm{K}\right)$ both the surface roughness and the growth exponent $\beta$ depend strongly on deposition angle. These results resolve a long-standing puzzle regarding the growth behavior of $\mathrm{Cu}∕\mathrm{Cu}\left(100\right)$ over this temperature range. Our results also demonstrate that, in general, the effects of deposition angle must be considered in low-temperature growth even for moderate deposition angles.

Figure 1

Comparison of experimental results of Ernst et al. (Ref. 15) (filled circles) and Botez et al. (Ref. 16) (open circles) for $\mathrm{Cu}∕\mathrm{Cu}\left(100\right)$ growth at $160\mathrm{K}$, along with full MD (dashed lines) and one-atom MD (solid lines) results for different angles of deposition. Thickness is indicated in monolayers (ML).

Figure 2

Comparison of experimental results of Ernst et al. (Ref. 15) (filled circles) and Botez et al. (Ref. 16) (open circles) for $\mathrm{Cu}∕\mathrm{Cu}\left(100\right)$ growth at $200\mathrm{K}$ with one-atom MD simulation results (solid lines) corresponding to normal and off-normal deposition.

Figure 3

Comparison of one-atom MD results at $160\mathrm{K}$ at normal and off-normal incidence (solid lines), with off-normal incidence simulation results $(\theta =64°)$ obtained without LR attraction (long dashes), as well as in the absence of both SR and LR attraction (short dashes). Experimental results from Refs. 15, 16 are included for reference.