Full text loading...
Scheme of the DCM (a) and RFP sputtering setups (b) for Ni deposition on Si(100), with AFM photos of the deposited islanded Ni films. In DCMP (a), the plasma is localized in the discharge in crossed magnetic and electric fields area above the Ni target, the discharge is remote from the substrate, direct contact between the plasma and the substrate is limited, and sputtered neutral Ni atoms are mostly deposited. In the RFP setup (b), the discharge plasma fills the entire chamber space, the plasma is in a direct contact with the substrate, and deposition is largely influenced by Ni ions that deposit onto the self-biased substrate. Thus, in the DCM case (a) Ni is deposited from the neutral flux, and in the RFP case (b) Ni ions are also deposited. The AFM image (b) demonstrates a much narrower size distribution and much better spatial uniformity of the ND positions.
Distributions of the minimum distances between the NDs (nearest neighbor distances) in the array deposited in the RFP (a) and DCMP (b). The RFPP produces arrays with much more uniform distribution of Ni NDs on the surface.
Fragment of simulation pattern of NDs and visualization of the surface adatom density field around the NDs on the surface (a); directions of adatom fluxes on the surface and separatrix lines that define the AZPs (b).
Two simulation domains with the computed AZPs. (a) Calculated AZPs in the DCM (a) and RFP (b) processes. The color pattern around the NDs represents the density of Ni adatoms. Insets present an enlarged view of the selected area in the ND array. The plasma-enhanced process demonstrates larger absorption zones around smaller NDs. NDs 1 and 2 are in the common absorption zone (AZ) in a neutral gas-based process (c), and form isolated AZs in the RFPP (d).
Dependence of the absorption zone coefficient on the ND radius for DCM and RFP processes. Significant scattering of the values is caused by different sizes of absorption zones of the individual NDs (1000 NDs were used in the simulations). RFPP demonstrates a strong dependence of the size of absorption zone on the ND size, thus promoting the equalization of the ND size distribution function.
Article metrics loading...