Proust Vanessa, Kirscher Quentin, Nguyen Thi Kim Ngan, Obringer Lisa, Ishii Kento, Rault Ludivine, Demange Valérie, Berthebaud David, Ohashi Naoki, Uchikoshi Tetsuo, Berling Dominique, Soppera Olivier, Grasset Fabien
CEA, DES, ISEC, DMRC, Université de Montpellier, F-30200 Marcoule, France.
Research Center for Functional Materials, National Institute for Materials Science (NIMS), Tsukuba 305-0044, Japan.
Nanomaterials (Basel). 2022 Jul 7;12(14):2334. doi: 10.3390/nano12142334.
In the frame of the nanoarchitectonic concept, the objective of this study was to develop simple and easy methods to ensure the preparation of polymorphic HfO2 thin film materials (<200 nm) having the best balance of patterning potential, reproducibility and stability to be used in optical, sensing or electronic fields. The nanostructured HfO2 thin films with micropatterns or continuous morphologies were synthesized by two different methods, i.e., the micropatterning of sol-gel solutions by deep ultraviolet (DUV) photolithography or the electrophoretic deposition (EPD) of HfO2 nanoparticles (HfO2-NPs). Amorphous and monoclinic HfO2 micropatterned nanostructured thin films (HfO2-DUV) were prepared by using a sol-gel solution precursor (HfO2-SG) and spin-coating process following by DUV photolithography, whereas continuous and dense monoclinic HfO2 nanostructured thin films (HfO2-EPD) were prepared by the direct EPD of HfO2-NPs. The HfO2-NPs were prepared by a hydrothermal route and studied through the changing aging temperature, pH and reaction time parameters to produce nanocrystalline particles. Subsequently, based on the colloidal stability study, suspensions of the monoclinic HfO2-NPs with morphologies near spherical, spindle- and rice-like shapes were used to prepare HfO2-EPD thin films on conductive indium-tin oxide-coated glass substrates. Morphology, composition and crystallinity of the HfO2-NPs and thin films were investigated by powder and grazing incidence X-ray diffraction, scanning electron microscopy, transmission electron microscopy and UV-visible spectrophotometry. The EPD and DUV photolithography performances were explored and, in this study, it was clearly demonstrated that these two complementary methods are suitable, simple and effective processes to prepare controllable and tunable HfO2 nanostructures as with homogeneous, dense or micropatterned structures.
在纳米结构概念框架下，本研究的目的是开发简单易行的方法，以确保制备出多晶型HfO₂薄膜材料（<200 nm），使其在用于光学、传感或电子领域时，在图案化潜力、可重复性和稳定性方面达到最佳平衡。通过两种不同方法合成了具有微图案或连续形态的纳米结构HfO₂薄膜，即通过深紫外（DUV）光刻对溶胶 - 凝胶溶液进行微图案化，或对HfO₂纳米颗粒（HfO₂ - NPs）进行电泳沉积（EPD）。使用溶胶 - 凝胶溶液前驱体（HfO₂ - SG）并通过旋涂工艺随后进行DUV光刻，制备了非晶和单斜晶HfO₂微图案化纳米结构薄膜（HfO₂ - DUV），而通过HfO₂ - NPs的直接EPD制备了连续且致密的单斜晶HfO₂纳米结构薄膜（HfO₂ - EPD）。通过水热法制备HfO₂ - NPs，并通过改变老化温度、pH值和反应时间参数进行研究，以制备纳米晶体颗粒。随后，基于胶体稳定性研究，使用形态接近球形（近球形）、纺锤形和稻粒形的单斜晶HfO₂ - NPs悬浮液，在导电铟锡氧化物涂层玻璃基板上制备HfO₂ - EPD薄膜。通过粉末和掠入射X射线衍射、扫描电子显微镜、透射电子显微镜和紫外可见分光光度法研究了HfO₂ - NPs和薄膜的形态、组成和结晶度。探索了EPD和DUV光刻性能，并且在本研究中清楚地表明，这两种互补方法是制备具有均匀、致密或微图案化结构的可控且可调谐HfO₂纳米结构的合适、简单且有效的工艺。
