摘要
An a-SiNx/nanocrystalline silicon [（nc-Si）/a-SiNx] sandwiched structure is fabricated in a plasma enhanced chemical vapour deposition （PECVD） system at low temperature （250℃）. The nc-Si layer is fabricated from a hydrogen-diluted silane mixture gas by using a layer-by-layer deposition technique. Atom force microscopy measurement shows that the density of nc-Si is about 2 ×10^11 cm^-2. By the pretreatment of plasma nitridation, low density of interface states and high-quality interface between the Si substrate and a-SiNs insulator layer are obtained. The density of interface state at the midgap is calculated to be 1 ×10^10 cm^-2eV^-1 from the quasistatic and high frequency C - V data. The charging and discharging property of nc-Si quantum dots is studied by capacitance-voltage （C- V） measurement at room temperature. An ultra-large hysteresis is observed in the C - V characteristics, which is attributed to storage of the electrons and holes into the nc-Si dots. The long-term charge-loss process is studied and ascribed to low density of interface states at SiNx/Si substrate.
An a-SiNx/nanocrystalline silicon [（nc-Si）/a-SiNx] sandwiched structure is fabricated in a plasma enhanced chemical vapour deposition （PECVD） system at low temperature （250℃）. The nc-Si layer is fabricated from a hydrogen-diluted silane mixture gas by using a layer-by-layer deposition technique. Atom force microscopy measurement shows that the density of nc-Si is about 2 ×10^11 cm^-2. By the pretreatment of plasma nitridation, low density of interface states and high-quality interface between the Si substrate and a-SiNs insulator layer are obtained. The density of interface state at the midgap is calculated to be 1 ×10^10 cm^-2eV^-1 from the quasistatic and high frequency C - V data. The charging and discharging property of nc-Si quantum dots is studied by capacitance-voltage （C- V） measurement at room temperature. An ultra-large hysteresis is observed in the C - V characteristics, which is attributed to storage of the electrons and holes into the nc-Si dots. The long-term charge-loss process is studied and ascribed to low density of interface states at SiNx/Si substrate.
基金
Supported by the National Basic Research Programme of China under Grant No 2006CB932202, and the National Natural Science Foundation of China under Grant Nos 60571008 and 60471021.
