Single-electron tunneling through Si nanocrystals dispersed in phosphosilicate glass thin films

Electrical transport properties of extremely thin phosphosilicate glass (PSG) films containing Si nanocrystals (nc-Si) a few nanometers in diameter were studied. Samples were prepared by cosputtering Si and PSG targets, and post-annealing. Periodic Coulomb staircases were clearly observed in the DC current–voltage (I–V) characteristics along the vertical direction of films. Although the step structure was broadened with increasing temperature, it remained up to 200 K. The I–V curve could be well fitted by Monte Carlo simulation with a simple double-barrier structure model. Advantages of using PSG instead of SiO2 as surrounding matrices of nc-Si to observe single-electron tunneling effects are discussed.