Department of Chemistry & Biochemistry and Materials Science Institute, University of Oregon , Eugene, Oregon 97403, United States.
School of Electrical Engineering and Computer Science, Oregon State University , Corvallis, Oregon 97331, United States.
ACS Appl Mater Interfaces. 2017 Mar 29;9(12):10897-10903. doi: 10.1021/acsami.7b00915. Epub 2017 Mar 14.
Metal oxide thin films are critical components in modern electronic applications. In particular, high-κ dielectrics are of interest for reducing power consumption in metal-insulator-semiconductor (MIS) field-effect transistors. Although thin-film materials are typically produced via vacuum-based methods, solution deposition offers a scalable and cost-efficient alternative. We report an all-inorganic aqueous solution route to amorphous lanthanum zirconium oxide (LaZrO, LZO) dielectric thin films. LZO films were spin-cast from aqueous solutions of metal nitrates and annealed at temperatures between 300 and 600 °C to produce dense, defect-free, and smooth films with subnanometer roughness. Dielectric constants of 12.2-16.4 and loss tangents <0.6% were obtained for MIS devices utilizing LZO as the dielectric layer (1 kHz). Leakage currents <10 A cm at 4 MV cm were measured for samples annealed at 600 °C. The excellent surface morphology, high dielectric constants, and low leakage current densities makes these LZO dielectrics promising candidates for thin-film transistor devices.
金属氧化物薄膜是现代电子应用中的关键组成部分。特别是，高介电常数材料对于降低金属-绝缘体-半导体（MIS）场效应晶体管的功耗很有意义。虽然薄膜材料通常是通过真空基方法生产的，但溶液沉积提供了一种可扩展且具有成本效益的替代方案。我们报告了一种全无机水性溶液途径来制备非晶态镧锆氧化物（LaZrO，LZO）介电薄膜。LZO 薄膜是通过金属硝酸盐的水性溶液旋涂而成，并在 300 至 600°C 的温度下退火，以生产出致密、无缺陷且光滑的薄膜，其表面粗糙度小于亚纳米级。利用 LZO 作为介电层的 MIS 器件可获得 12.2-16.4 的介电常数和 <0.6%的损耗角正切（1 kHz）。在 600°C 退火的样品中，测量到的漏电流 <10 A cm 在 4 MV cm 下。这些 LZO 电介质具有优异的表面形貌、高介电常数和低漏电流密度，使其成为薄膜晶体管器件的有前途的候选材料。
