雪崩热电子注入研究富氮SiO_xN_y纳米级薄膜的陷阱特性

采用雪崩热电子注入技术研究了富氮 Si Ox Ny 纳米级薄膜的陷阱特性。观察到该薄膜存在着受主型电子陷阱 ,随着注入的增长、界面上产生的这种陷阱将起主导作用 ,其密度大过施主型界面电子陷阱。揭示出界面陷阱密度在禁带中分布 ,其密度随雪崩注入剂量增加而增大 ,禁带上半部增大得尤其显著。指出雪崩注入过程中在 Si/ PECVD Si Ox Ny 界面上产生两种性质不同的电子陷阱 ,并给出它们在禁带中的位置及密度大小关系。支持了界面陷阱来源于悬挂键的物理模型 ,由于本实验的重要结果可用该理论模型圆满地解析。给出 PECVD形成纳米级薄膜的优化工艺条件 ,该条件成膜的界面特性良好、耐压范围高、抗雪崩注入能力及其他电子特性也较好

Study of Trap Characteristics of Nitrogen-rich SiOxNy Thin Film in Nanometre Range by Avalanche Hot-electron Injection

Trap characteristics of nitrogen rich SiO x N y thin film in nanometre range have been studied by means of avalanche hot electron injection technique. Electron trap of acceptor type, existing in the film, has been observed. With the increase of avalanche injection, the created electron trap of acceptor type in interface shall play a leading role. Its density is larger than the electron trap of donor type in interface. The distributions of interface trap density in forbidden band have been revealed. Its densities are increased with the avalanche injection dose. The densities of upper half part in forbidden band are increased more markedly than that densities of below half part. It is indicated that two kinds of electron traps, which have different properties, were generated in the Si/PECVD SiO x N y interface during avalanche injection. The positions in forbidden band and quantitative density relationship of these two electron traps are provided. The physical model of interface trap which is originated by the suspension was supported. The important result of experiment work is explained successfully by the physical model. The process condition of the thin film in nanometre range formed by PECVD is optimized. The thin film formed by the optimized condition possess better interface characteristic、 higher breakdown voltage、 stronger ability to resist avalanche injection and other good electrical characteristics.