Ultrasmooth silver thin films deposited with a germanium nucleation layer.
We demonstrate an effective method for depositing smooth silver (Ag) films on SiO(2)/Si(100) substrates using a thin seed layer of evaporated germanium (Ge). The deposited Ag films exhibit smaller root-mean-square surface roughness, narrower peak-to-valley surface topological height distribution, smaller grain-size distribution, and smaller sheet resistance in comparison to those of Ag films directly deposited on SiO(2)/Si(100) substrates. Optically thin ( approximately 10-20 nm) Ag films deposited with approximately 1-2 nm Ge nucleation layers show more than an order of magnitude improvement in the surface roughness. The presence of the thin layer of Ge changes the growth kinetics (nucleation and evolution) of the electron-beam-evaporated Ag, leading to Ag films with smooth surface morphology and high electrical conductivity. The demonstrated Ag thin films are very promising for large-scale applications as molecular anchors, optical metamaterials, plasmonic devices, and several areas of nanophotonics.
Logeeswaran Vj
Department of Electrical & Computer Engineering, Kemper Hall, University of California at Davis, One Shields Avenue, Davis, California 95616, USA.
Kobayashi
Nobuhiko P
NP
Islam
M Saif
MS
Wu
Wei
W
Chaturvedi
Pratik
P
Fang
Nicholas X
NX
Wang
Shih Yuan
SY
Williams
R Stanley
RS
D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D005857:Germanium / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008567:Membranes, Artificial; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D012666:Semiconductors; D012834:Silver / Q000737:chemistry*; D013499:Surface Properties
D046911:Macromolecular Substances; D008567:Membranes, Artificial; D005857:Germanium; D012834:Silver