铪基稀土高k栅介质外延薄膜的微结构调制及其介电性能研究

项目名称： 铪基稀土高k栅介质外延薄膜的微结构调制及其介电性能研究

项目编号： No.51202013

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 无机非金属材料学科

项目作者： 张心强

作者单位： 北京有色金属研究总院

项目金额： 25万元

中文摘要： 目前非晶铪基高k栅介质在16 nm及以下技术节点应用时将面临更严峻的挑战：等效氧化物厚度不大于0.5 nm，带隙以及带隙偏移要足够大，漏电流要足够小。外延高k栅介质薄膜被认为是实现此目的最佳方法之一。然而，常态下HfO2的晶体结构为单斜相，很难在立方结构衬底上外延生长。稀土Gd、La的掺入对HfO2正方相或立方相稳定性、晶格参数以及相应的带隙、缺陷等有较大影响，为实现外延提供可能，然而目前缺乏系统的实验且尚未建立相关的理论研究。本项目拟展开GdHfO和LaHfO单晶高k栅介质薄膜的研究，研究Gd和La掺杂对HfO2晶体结构和晶格参数作用机制，以及其对HfO2外延薄膜带隙、氧空位、介电性能、界面反应和缺陷的作用机理，实现对结构特性及能带特性的调控。同时结合介电性能表征进行理论探讨，为铪基稀土高k栅介质在未来纳米集成电路中的应用提供科学依据。

中文关键词： 高介电常数；稀土氧化物；外延；栅介质；阻变

英文摘要： Hf-based amorphous gate dielectrics in use would face a great challenge of applying to 16 nm and the following technology node，such as (equivalent oxide thickness) EOT<0.5nm, large band gap and offset, low leakage current density. There is one of best methods to epitaxially grow high k dielectrics films. However, it is usually difficult to grow epitaxial films on cubic substrates, due to monoclinic phase of HfO2 at room temperature. Cubic Lattice stability, lattice parameters, band gap and defect of HfO2 are greatly affected by doping Gd or La, but the related system experiments and basic theories have not been made. This project is intended to make research of GdHfO and LaHfO epitaxial high k gate dielectrics. Internal mechanisms of crystal structure and lattice parameter between Gd or La and HfO2 will be studied. Action mechanisms of band gap, oxygen vacancies, interface reaction and defects in doped epitaxial HfO2 films will be discussed too. Crystal and energy properties could be controlled during the preparation. Basic date of epitaxial films will be given. The research results will provide theoretical guides of composition and process design for applications of high k dielectrics in the future nanometer integrated circuit on the base of the combination of electrical properties and related basic theory. At

英文关键词： high permitivity；rare metal oxides；epitaxy；gate dielectrics；resistive switching