相邻材料之间的相互扩散现象在半导体器件架构中非常普遍，并且可能对工业提出主要的可靠性挑战。为了充分捕捉和更好地理解这些现象，实验方法必须超越静态和事后研究，包括原位和操作中的设置。这里，软X射线和硬X射线光电子能谱学（SXPS和HAXPES）用于实时监测跨代理器件的扩散。该器件由Si/SiO \textsubscript{2} /Ti $_x$ W $_{1-x}$（300 nm）/Cu（25 nm）薄膜材料叠层组成，其中Ti $_x$ W $_{1-x}$膜充当Si和Cu之间的扩散阻挡层。扩散的监测是通过在原位退火到673 K的同时连续收集光谱来实现的。Ti内的TiW被发现是高度流动的退火过程中，扩散出的障碍，并积累在Cu表面。增加Ti $_x$ W $_{1-x}$膜内的Ti浓度增加了累积的Ti的量，并且在低至550 K的温度下首先在Cu表面检测到Ti。令人惊讶的是，在低Ti浓度（$x$ = 0.054）下，W也是可移动的并且与Ti一起扩散。这些结果为扩散屏障组合物在器械应用期间对其功效的重要性提供了关键证据，从而深入了解了其有效性和局限性的机制。
英文摘要：
Interdiffusion phenomena between adjacent materials are highly prevalent in semiconductor device architectures and can present a major reliability challenge for the industry. To fully capture and better understand these phenomena, experimental approaches must go beyond static and post-mortem studies to include in-situ and in-operando setups. Here, soft and hard X-ray photoelectron spectroscopy (SXPS and HAXPES) is used to monitor diffusion in real-time across a proxy device. The device consists of a Si/SiO\textsubscript{2}/Ti$_x$W$_{1-x}$(300 nm)/Cu(25 nm) thin film material stack, with the Ti$_x$W$_{1-x}$ film acting as a diffusion barrier between Si and Cu. The monitoring of diffusion is achieved through the continuous collection of spectra whilst in-situ annealing to 673 K. Ti within the TiW is found to be highly mobile during annealing, diffusing out of the barrier and accumulating at the Cu surface. Increasing the Ti concentration within the Ti$_x$W$_{1-x}$ film increases the quantity of accumulated Ti, and Ti is first detected at the Cu surface at temperatures as low as 550 K. Surprisingly, at low Ti concentrations ($x$ = 0.054), W is also mobile and diffuses alongside Ti. These results provide crucial evidence for the importance of diffusion barrier composition on their efficacy during device application, delivering insights into the mechanisms underlying their effectiveness and limitations.
Ultrafast transport and energy relaxation of hot electrons in Au/Fe/MgO(001) heterostructures analyzed by linear time-resolved photoelectron spectroscopy
A new type-II lepidocrocite-type TiO2/GaSe heterostructure: Electronic and optical properties, bandgap engineering, interaction with ultrafast laser pulses
Combining advanced photoelectron spectroscopy approaches to analyse deeply buried GaP(As)/Si(100) interfaces: Interfacial chemical states and complete band energy diagrams
Dirac semimetal strontium iridate thin films with strong spin-orbit interaction for magnetic heterostructures
Kotelnikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences（俄罗斯科学院科捷利尼科夫无线电工程与电子研究所）；National Research University "Higher School of Economics", Faculty of Physics（国立研究大学高等经济大学物理系）；Moscow Institute of Physics and Technology (National Research University)（莫斯科物理技术学院（国立研究大学））
Electronic and magnetic structure of epitaxial NiO/Fe$_3$O$_4$(001) heterostructures grown on MgO(001) and Nb-doped SrTiO$_3$(001)
我们研究了一些磁铁矿基薄膜的基本化学，电子和磁性。主要研究了MgO（001）和Nb-SrTiO $_3$（001）衬底上生长的NiO/Fe $_3$ O $_4$（001）双层薄膜。我们比较的结果与纯Fe $_3$ O $_4$（001）薄膜。结果发现，磁铁矿层被氧化，Fe $^{3+}$占主导地位的表面由于磁赤铁矿（$γ$ -Fe $_2$ O $_3$）的形成，这减少了磁铁矿层的厚度。从约20 nm的层厚度上的阳离子分布接近于化学计量的Fe $_3$ O $_4$。在NiO和Fe $_3$ O $_4$之间的界面处，我们发现Ni处于二价态，在Ni 2 p核心水平X射线光电子能谱中具有NiO典型的明确的光谱特征。通过XMCD可以排除明显的NiFe $_2$ O $_4$中间层的形成。磁光克尔效应测量揭示了显着更高的矫顽场相比，MgO（001）和45 $^{\circ}$旋转磁易轴上生长的磁铁矿薄膜。我们讨论了磁性层的自旋磁矩，发现磁矩随薄膜厚度的增加而增加。在较低的厚度下，在Nb-SrTiO $_3$上生长的NiO/Fe $_3$ O $_4$薄膜的自旋磁矩显著降低。20 nm或更高的厚度导致自旋磁矩接近块状磁铁矿的自旋磁矩。
Ultrafast electron dynamics in Au/Fe/MgO(001) analyzed by Au- and Fe-selective pumping in time-resolved two-photon photoemission spectroscopy: Separation of excitations in adjacent metallic layers
Tuning the Coercive Field in Ferroelectric Hf0.5Zr0.5O2-Al2O3 Heterostructures via Interfacial Charge Dynamics
School of Materials Science and Engineering, Georgia Institute of Technology（佐治亚理工学院材料科学与工程学系）；School of Electrical and Computer Engineering, Georgia Institute of Technology（佐治亚理工学院电气与计算机工程学系）；Center for Nanophase Materials Sciences, Oak Ridge National Laboratory（橡树岭国家实验室纳米相材料科学中心）；The Institute for Matter and Systems, Georgia Institute of Technology（佐治亚理工学院物质系统研究所）
Direct observation of decoupled Dirac states at the interface between topological and normal insulators
在拓扑绝缘体中的几种应用和奇异效应依赖于拓扑绝缘体和正常绝缘体之间界面处螺旋狄拉克态的存在。在本工作中，我们利用低能角分辨光电子能谱学对Si（111）衬底上生长的Bi $_2$ Se $_3$薄膜和Bi $_2$ Te $_3$ /Bi $_2$ Se $_3$异质结构的界面态进行了研究和表征。结果表明，狄拉克费米子确实存在于拓扑-正常-绝缘体边界，而不存在于拓扑-拓扑-绝缘体界面。此外，它表明，能带弯曲内存在的拓扑绝缘体膜导致的界面和表面态的能量的实质性分离。这些结果为进一步研究和实现拓扑绝缘体薄膜异质结构中的界面相关现象奠定了基础。
Lattice parameters of Sc$_{\boldsymbol{\mathsf{x}}}$Al$_{\boldsymbol{\mathsf{1-x}}}$N layers grown on GaN(0001) by plasma-assisted molecular beam epitaxy
