快重离子辐照高k材料引起的电学特性退化：潜径迹精细结构形成和热稳定性的影响研究

宇宙射线中的高能重离子除导致宇航元器件单粒子效应外，还会在器件材料中产生永久性的结构损伤，影响其长期可靠性。MOS器件中的栅介质材料是对于高能重离子辐照最为薄弱的环节。在新型纳米器件中，栅介质材料SiO2由于已达物理极限，已被高k材料所取代。而且，深空探测迫切需求一种可通过热退火修复空间辐射引起的器件性能退化的“自愈性”纳米器件。因此，本项目的开展对于评估纳米器件在空间辐射环境下的长期可靠性及“自愈性”纳米器件热退火参数的确定有重要意义。本项目依托兰州重离子研究装置，以HfO2等几种典型的高k材料及其MOS器件为研究对象，通过快重离子辐照结合多种表征手段的系统研究，获得快重离子在这些材料中潜径迹精细结构形成与辐照参数的依赖关系。特别是通过高能重离子微束手段对MOS结构的低注量定位辐照及退火实验，揭示少数离子甚至单个离子引起器件电学特性退化与微观结构损伤的内在联系。

High-energy heavy cosmic rays can cause permanent damage in the material of electronics, except inducing the single event effect, which finally affect the long-term reliability of devices. The gate dielectric of MOS devices is very sensitive to the high-energy heavy ions irradiation. With the further downscaling of the transistors, concentional SiO2 cannot meet the gate dielectric demand and it has been replaced by high dielectric constant (high-k) materials. On the other hand, the sustainable electronics that can recover the space-radiation-induced damage by thermal annealing is very promising for the deep space missions. Therefore, it is very significant to investigate the influence of the ion latent tracks as well as its thermal stability on the electrical properties of high-k materials induced by high-energy heavy ions. This study is very essential for the evaluation of long-term reliability of nano-devices and determination of parameters of themal annealing for the sustainable electronics. In this proposal, the fine structure formation of latent tracks as a function of various irradiation parameters in several typical high-k insulators, including HfO2, ZrO2 and TiO2, will be characterized. Especially, it is expected to disclose the influence on the electrical properties of MOS device caused by several or even single heavy ion irradiation-induced microscopic structure damage by using the heavy ion micro-beam irradiation combined with thermal annealing experiments. These results will also provide experimental data for the understanding mechanism of interaction between swift heavy ions and materials.