体心立方金属中空位迁移规律

本文在考虑空位浓度对空位迁移能的影响和双空位效应的情况下,给出了体心立方金属中空位流与空位浓度梯度之间的定量关系。并指出当空位浓度超过一个临界值时,空位将向其浓度大的地方迁移。本文所用方法也可用于其它金属。 关键词：     

Stress-induced leakage current characteristics of PMOS fabricated by a new multi-deposition multi-annealing technique with full gate last process

In the process of high-k films fabrication, a novel multi deposition multi annealing(MDMA) technique is introduced to replace simple post deposition annealing. The leakage current decreases with the increase of the post deposition annealing(PDA) times. The equivalent oxide thickness(EOT) decreases when the annealing time(s) change from 1 to 2. Furthermore,the characteristics of SILC(stress-induced leakage current) for an ultra-thin SiO_2/HfO_2 gate dielectric stack are studied systematically. The increase of the PDA time(s) from 1 to 2 can decrease the defect and defect generation rate in the HK layer. However, increasing the PDA times to 4 and 7 may introduce too much oxygen, therefore the type of oxygen vacancy changes.     

辐照材料的肿胀理论(Ⅱ) 偏吸率与肿胀公式

本文用分区的方法,得到了在同时计及位错应力场和辐照效应的情况下,位错周围点缺陷分布函数的零级、一级和二级近似解,进而得到了偏吸率。利用所得的偏吸率及文献[1]的结果,给出了新的肿胀公式。新公式优于前人的理论,不仅理论本身自洽,而且与实验符合较好。     

辐照材料的肿胀理论(Ⅰ)——中性尾闾

本文从反应扩散方程出发,研究在辐照条件下,微洞和位错(无应力场)周围点缺陷的分布情况。对含有点缺陷复合项的定态的反应扩散方程,给出了一种近似求解的方法并分别得到了微洞和位错吸收点缺陷的汇强度。从所得结果与前人略去复合项的结果比较可知,微洞较大时,复合项对汇强度的影响变得重要;对于位错,当点缺陷产生率较大时,考虑了复合项后所得的汇强度可达前人结果的1.5倍以上。 关键词：     

Study on influences of TiN capping layer on time-dependent dielectric breakdown characteristic of ultra-thin EOT high-k metal gate NMOSFET with kMC TDDB simulations

The thickness effect of the TiN capping layer on the time dependent dielectric breakdown(TDDB) characteristic of ultra-thin EOT high-k metal gate NMOSFET is investigated in this paper.Based on experimental results,it is found that the device with a thicker TiN layer has a more promising reliability characteristic than that with a thinner TiN layer.From the charge pumping measurement and secondary ion mass spectroscopy(SIMS) analysis,it is indicated that the sample with the thicker TiN layer introduces more Cl passivation at the IL/Si interface and exhibits a lower interface trap density.In addition,the influences of interface and bulk trap density ratio N_(it)/N_(ot) are studied by TDDB simulations through combining percolation theory and the kinetic Monte Carlo(kMC) method.The lifetime reduction and Weibull slope lowering are explained by interface trap effects for TiN capping layers with different thicknesses.     

做人、做事、做事业——记恩师黄祖洽先生

<正>1师生缘1982年,我将要从中国科学技术大学本科毕业,正在考虑报考理论物理研究生.正巧我父亲的同事说北京师范大学低能核物理研究所最近来了一位非常著名的科学家黄祖洽院士做所长.黄先生是我国研制原子弹氢弹的功臣,为此他作为主要作者之一获得了国家自然科学一等奖,且于1980年当选为中国科学院学部委员(院士).当时我查了一下招生简章发现黄先生的招生方向正是我所喜欢的,就以     

辐照材料的肿胀理论(Ⅰ) 中性尾闾

本文从反应扩散方程出发,研究在辐照条件下,微洞和位错(无应力场)周围点缺陷的分布情况。对含有点缺陷复合项的定态的反应扩散方程,给出了一种近似求解的方法并分别得到了微洞和位错吸收点缺陷的汇强度。从所得结果与前人略去复合项的结果比较可知,微洞较大时,复合项对汇强度的影响变得重要;对于位错,当点缺陷产生率较大时,考虑了复合项后所得的汇强度可达前人结果的1.5倍以上。     

《磁光效应》实验

本文介绍一套自制的《磁光效应》教学实验装置，用光电法精密测量Ｆａｒａｄａｙ旋光谱．主要介绍实验装置以及用它测量的Ｆａｒａｄａｙ旋光谱．     

Crystallization behaviors of ultrathin Al-doped HfO_2 amorphous films grown by atomic layer deposition

In this work, ultrathin pure HfO_2 and Al-doped HfO_2films(about 4-nm thick) are prepared by atomic layer deposition and the crystallinities of these films before and after annealing at temperatures ranging from 550℃ to 750℃ are analyzed by grazing incidence x-ray diffraction. The as-deposited pure HfO_2 and Al-doped HfO_2 films are both amorphous. After550-℃ annealing, a multiphase consisting of a few orthorhombic, monoclinic and tetragonal phases can be observed in the pure HfO_2 film while the Al-doped HfO_2 film remains amorphous. After annealing at 650℃ and above, a great number of HfO_2 tetragonal phases, a high-temperature phase with higher dielectric constant, can be stabilized in the Al-doped HfO_2 film. As a result, the dielectric constant is enhanced up to about 35. The physical mechanism of the phase transition behavior is discussed from the viewpoint of thermodynamics and kinetics.     

辐照材料的肿胀理论(Ⅱ)——偏吸率与肿胀公式

本文用分区的方法,得到了在同时计及位错应力场和辐照效应的情况下,位错周围点缺陷分布函数的零级、一级和二级近似解,进而得到了偏吸率。利用所得的偏吸率及文献[1]的结果,给出了新的肿胀公式。新公式优于前人的理论,不仅理论本身自洽,而且与实验符合较好。 关键词：