Dopant‐Cluster‐Mediated Electron Transport in the Excess‐Current Region of Ultrathin Silicon pn Junctions

Electron tunneling transport in ultrathin, highly doped silicon pn junctions is likely dominated by quasi‐one‐dimensional conduction paths. As devices are miniaturized, and doping concentrations are increased, deviations from the three‐dimensional model of transport may occur in the form of current inflections, representing local band‐to‐band tunneling (BTBT) transport. This work proposes a method to interpret such current inflections, emerging particularly in the excess‐current region of nanoscale silicon pn diodes, correlated with the formation of quasi‐one‐dimensional BTBT paths. By experimental and numerical study on ultrathin, highly doped silicon pn junctions, inflections in the excess‐current region can be attributed to the presence of deep‐potential multiple‐dopant clusters. The findings described here can encourage the development of a new approach to detect the presence of dopant clusters with specific characteristics, confined in quasi‐one‐dimensional paths in ultrathin pn junctions.