Modulating Surface Roughness of Low Temperature PECVD Germanium using Multilayer Drop Casting of 2.85 nm Silicon Nanoparticles

We investigate the effect of multilayer drop casting of silicon nanoparticles (Si-NPs) on the roughness of Germanium (Ge) films grown by low temperature plasma enhanced chemical vapor deposition (PECVD) germanium on an n-doped silicon (Si) substrate. The Si-NPs allow surface roughening and texture modification on a nanoscale. The surface roughness is shown to be controlled using the drop casting method in ambient pressure and temperature followed by topography measurements obtained via atomic force microscopy (AFM). By using the layer-by-layer deposition technique, with an increment of 100 μL each, we fabricated 5 samples with a total of 100 μL, 200 μL, 300 μL, 400 μL and 500 μL of the Si-NPs dispersion volume. A root mean square (RMS) roughness (Rq) of 8 nm is recorded for a ~30 nm thick Si-NPs nano-film.