MIS结构中快速热氮化的SiO_xN_y膜电荷特性

Charge Characteristics of Rapid Thermal Nitrided SiO_xN_y Film in MIS Structure

本文报导了采用光I—V法研究MIS结构中新型的快速热氮化的SiO_xN_y膜电荷特性。给出这种介质膜和传统的SiO_2膜的体电荷面密度及其分布重心位置等实验结果。文中还用“改进”的雪崩热电子注入装置研究MIS结构中快速热氮化的SiO_xN_y膜的电荷特性。结果指出:快速热氮化后的再氧化工艺可有效地降低SiO_xN_y膜的体电子陷阱和界面陷阱密度;雪崩注入到一定程度后平带电压漂移出现“回转效应”,随后又前漂,弱呈现“N”形。本文就此提出了物理解释。结果还给出:界面电荷陷阱密度在禁带中分布随雪崩注入剂量(时间)的变化关系。文中还对实验结果进行了分析讨论。

In this paper it is reported that the charge characteristics of new rapid thermal nitrided (RTN) SiOxNy film in MIS structure was investigated by the photo I-V method. The experimental results gave the bulk charge density, its distribution centroid position etc. for the RTN SiOxNy film and the conventional SiO2 film. This characteristics of the RTN SiOxNy film is also studied by the 'improved'instrument of avalanche hot-electron injection and the C-V technique. The result indicated that the reoxidation processing after RTN could reduce effectively the densities of bulk electron trapping and interface state in the SiOxNy films. The experimental results also showed that the flatband voltage shift presented 'turnaround effect' after a certain amounts of avalanche hot-electrons injected, subsequently, this shift occurred forward, and weakly-presented 'N' form. A physical model is given to explain the phenomenon. The change relationship of energy distribution for interface state density with injection dose is obtained. The theoretical analyses and discussions of these experimental results are made in this paper.