Authors: C.Y. Ng, M. Yang, J.I. Wong and T.P. Chen
Affilation: Nanyang Technological University, Singapore
Pages: 435 - 438
Keywords: dielectric constant, silicon nanocrystal, effective medium approximation
The static dielectric constant of isolated silicon nanocrystal (nc-Si) embedded in a SiO2 thin film synthesized by Si+ implantation has been determined from capacitance measurement based on the Maxwell-Garnett effective medium approximation and the Stopping and Range of Ions in Matter (SRIM) simulation. The nc-Si in the SiO2 can be modeled based on multi sub-layers model with each sub-layer has an equal thicknesses. For the nc-Si with a mean size of ~4.5 nm, the dielectric constant so determined is 9.6, being consistent with a theoretical prediction. This value is significantly lower than the static dielectric constant (11.9) of bulk crystalline Si, indicating the significance of nc-Si quantum size effect. The information of nc-Si dielectric constant is not only important to the fundamental physics but also useful to the design and modeling of nc-Si-based memory devices.