Copper nanoparticles deposited inside the pores of anodized aluminium oxide using atomic layer deposition

Equally sized copper nanoparticles were deposited in the pores (200 nm) of anodic alumina membranes (Whatman Anodisc) using a low-temperature Atomic Layer Deposition technique. Copper was deposited from gas pulses of copper chloride and a water/hydrogen gas mixture. By employing long gas pulse lengths (30 s) it was possible to obtain an equal coverage of copper particles throughout the pores of the membrane. The aspect ratio (length of pores over width of pores) was 350. By varying the number of cycles, the size of the particles could be varied from a few nanometers up to 60–70 nm. Scanning electron microscopy was used to estimate the size and distribution of the copper particles. X-ray diffraction confirmed that the particles consisted of metallic copper.