Phase transition of high-dielectric insulating films studied by extremely asymmetric X-ray diffraction and X-ray photoelectron spectroscopy

利用同步辐射掠入射x射线衍射（GIXRD）研究了HfO_2和hfoox薄膜的结晶过程。采用原子层沉积法（ALD）在化学二氧化硅界面层上制备了HfO_2和hfa10ox薄膜。沉积的HfO_2薄膜的x射线衍射（XRD）图谱不仅包含单斜相，还包含正交相或四方相。随着退火温度的升高，正交相或四方相减少或消失。hhfalox薄膜在900℃退火后结晶。结晶相为CaF_2型立方相。利用极不对称x射线衍射研究了沉积后退火对HfO_2/Si界面的影响。对比退火前后试样的摇摆曲线，发现沉积后退火过程中，在HfO_2层与衬底的界面处生长了密度为3 g/cm^3的界面层。沉积样品的振动曲线的综合强度的波长依赖关系随着观测位置的变化而波动。这种波动被退火抑制了。从这些结果我们得出结论，引入到衬底的应变在退火后变得均匀。此外，通过曲线拟合定量估计应变，揭示了HfO_2层下存在压缩应变。研究了在不同退火条件下，采用逐层沉积退火（l - d&a）法制备的HfA10x(N)/SiO_2/Si薄膜。在这一次，在不同的温度下，在NH_3环境中进行原位退火。此外，对部分样品进行了沉积后退火（PDA）处理。对于每个样品，用应变敏感x射线衍射评估了界面晶格应变，用x射线光电子能谱（XPS）测量了Al原子附近的局部介电常数。通过测量放牧入射条件下Si（001）衬底的Si 113反射的x射线摇摆曲线来观察应变场。结果表明，在不含PDA的情况下，随着原位退火温度的升高，压缩应变的引入使得局部介电常数降低。对于PDA样品，在不同的原位退火温度下，晶格应变和局部介电常数的差异很小。少

We have studied the crystallization process of HfO_2 and HfAlOx films using grazing incidence X-ray diffraction (GIXRD) with synchrotron radiation. The HfO_2 and HfA1Ox films were grown by atomic layer deposition (ALD) on a chemical Si02 interfacial layer. X-ray diffraction (XRD) patterns of the HfO_2 film as-deposited contain not only the monoclinic phase but also the orthorhombic or tetragonal phase. With increasing annealing temperature, the orthorhombic or tetragonal phase decreases and disappears. The HfAlOx film crystallized after annealing at 900 ℃. The crystallographic phase was the cubic phase of CaF_2 type.We studied the effect of post-deposition annealing on a HfO_2/Si interface of by extremely asymmetric X-ray diffraction. Comparing the rocking curves before annealing the sample with those of the annealed sample, it is found that an interfacial layer with a density of 3 g/cm^3 grows at the interface between the HfO_2 layer and the substrate during post-deposition annealing. … More The wavelength dependency of the integrated intensities of the rocking curve for the as-deposited sample fluctuated with the observation position. This fluctuation was suppressed by annealing. From these results we concluded that the strain introduced into the substrate becomes homogeneous by annealing. Moreover, a quantitative estimation of the strain by curve fitting reveals the existence of compressive strain under the HfO_2 layer.We studied HfA10x(N)/SiO_2/Si films which were fabricated by the layer-by-layer deposition and annealing (LL-D＆A) method with different annealing conditions. In this time, in-situ annealing was performed at various temperatures in a NH_3 ambient. In addition, post-deposition annealing (PDA) was performed for some samples. For each sample, the interfacial lattice strain was evaluated using strain-sensitive X-ray diffraction and the local dielectric constant near the Al atoms was measured by X-ray photoelectron spectroscopy (XPS). Observation of the strain field was done by measuring the X-ray rocking curve of the Si 113 reflection of the Si (001) substrate under grazing incidence conditions. It was found that in the case of the samples without PDA, for higher in-situ annealing temperatures compressive strain is introduced and the local dielectric constant becomes lower. For the samples with PDA, the differences of the lattice strain and the local dielectric constant are small for different in-situ annealing temperatures. Less