Limiting Regimes for Electron-Beam Induced Deposition of Copper from Aqueous Solutions containing Surfactants.

Focused electron beam induced deposition of pure materials from aqueous solutions has been of interest in recent years. However, controlling the liquid film in partial vacuum is challenging. Here we modify the substrate to increase control over the liquid layer in order to conduct a parametric study of copper deposition in an environmental scanning electron microscope. We identified the transition from electron to mass-transport limited deposition as well as two additional regimes characterized by aggregated and high-aspect ratio deposits. We observe a high deposition efficiency of 1-10 copper atoms per primary electron that is consistent with a radiation chemical model of the deposition process.