Suppressing Effects of Ag Wetting Layer on Surface Conduction of Er Silicide/Si(001) Nanocontacts
Qing Han1,2, Qun Cai1,2**
1State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433 2Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093
Abstract：Current-voltage electrical characteristics of Er silicide/Si(001) nanocontacts are measured in situ in a scanning tunneling microscopy system. Introduced as a new technique to suppress surface leakage conduction on Si(001), a silver wetting layer is evaporated onto the substrate surface kept at room temperature with ErSi$_{2}$ nanoislands already existing. The effects of the silver layer on the current-voltage characteristics of nanocontacts are discussed. Our experimental results reveal that the silver layer at coverage of 0.4–0.7 monolayer can suppress effectively the current contribution from the surface conduction path. After the surface leakage path of nanocontacts is obstructed, the ideality factor and the Schottky barrier height are determined using the thermionic emission theory, about 2 and 0.5 eV, respectively. The approach adopted here could shed light on the intrinsic transport properties of metal-semiconductor nanocontacts.
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2018, Vol. 35 
