Multi-component nanostructure design by atomic shadowing

This paper presents a method for multi-component three dimensional nanostructuring during physical vapor deposition, termed simultaneous opposite glancing angle deposition (SO-GLAD), which exploits atomic shadowing effects to control both the shape and the composition of nanorods parallel (in-plane) and perpendicular to the rod-axis. Periodic arrays of ~ 200-nm-wide Si–Ta two-component rods are grown by SO-GLAD onto monolayers of self-assembled close-packed 260-nm-diameter silica spheres. Simultaneous deposition of Si and Ta from opposite sides on a stationary substrate yields nanorods consisting of laterally separated Si and Ta components, since atomic shadowing causes deposition only onto the sphere-sides that are exposed to the respective deposition fluxes. Sequential deposition with a stationary and rotating substrate results in zigzag two-component nanosprings and vertical multilayer nanorods, respectively. A checkerboard arrangement is achieved by simultaneous deposition with intermittent 180° substrate rotations.