Liquid-phase deposition of thin Si and Ge films based on ballistic hot electron incidence

Abstract

Using the reducing activity of ballistic hot electrons emitted from a nanocrystalline silicon (nc-Si) diode, it is demonstrated that thin Si and Ge films can be deposited under a situation that output electrons directly impinge upon a SiCl4 or GeCl4 solution-coated target substrate located in close proximity to the nc-Si emitter. After the electron incidence, uniform deposition of thin Si or Ge films was clearly observed in the irradiated area. In accordance with spectroscopic characterizations, no signs of contaminations were detected in deposited thin Si and Ge films, and those films exhibit features as oxidized nano-clusters. It is also shown that from a thermodynamic viewpoint, the output electron energy of the nc-Si emitter is suitable for promoting preferential reduction of target ions within the penetration depth in solutions followed by the nuclei formation.