Title |
Characterization of Electrical Properties of Si Nanocrystals Embedded in a SiO_{2} Layer by Scanning Probe Microscopy |
Authors |
김정민(Kim, Jung-Min) ; 허현정(Her, Hyun-Jung) ; 강치중(Kang, Chi-Jung) ; 김용상(Kim, Yong-Sang) |
Keywords |
Si Anocrystal ; Interface States ; Laser Ablation ; Scanning Probe Microscopy ; Localized Electrical Properties |
Abstract |
Si nanocrystal (Si NC) memory device has several advantages such as better retention, lower operating voltage, reduced punch-through and consequently a smaller cell area, suppressed leakage current. However, the physical and electrical reasons for this behavior are not completely understood but could be related to interface states of Si NCs. In order to find out this effect, we characterized electrical properties of Si NCs embedded in a SiO_{2} layer by scanning probe microscopy (SPM). The Si NCs were generated by the laser ablation method with compressed Si powder and followed by a sharpening oxidation. In this step Si NCs are capped with a thin oxide layer with the thickness of 1 ~2 nm for isolation and the size control. The size of 51 NCs is in the range of 10 ~50 m and the density around 10^{11}/cm^{2} It also affects the interface states of Si NCs, resulting in the change of electrical properties. Using a conducting tip, the charge was injected directly into each Si NC, and the image contrast change and dC/dV curve shift due to the trapped charges were monitored. The results were compared with C-V characteristics of the conventional MOS capacitor structure. |