Jia Yifan, Fu Yi, Liu Xiangtai, Wang Zhan, Jiang Pengcheng, Lu Qin, Wang Shaoqing, Guan Yunhe, Li Lijun, Chen Haifeng, Hao Yue
Key Laboratory of Advanced Semiconductor Devices and Materials, Xi'an University of Posts Telecommunications, Xi'an, 710121, China.
Wide Bandgap Semiconductor Technology Disciplines State Key Laboratory, Xidian University, Xi'an, 710071, China.
Sci Rep. 2025 Jan 7;15(1):1154. doi: 10.1038/s41598-025-85686-9.
(AlO)(HfO) films with varying compositions were deposited on silicon substrates via plasma-enhanced atomic layer deposition (PEALD), and metal-oxide-semiconductor (MOS) capacitors were fabricated. The impact of varying induced Al content on the dielectric properties of HfO was examined through electrical measurements. The results showed that increasing Al content raised the flat-band voltage, reduced the interface state density (D), and significantly lowered the leakage current at a given voltage. Moreover, room temperature I-V measurements indicated that Schottky emission (~ 0.8-4.8 MV/cm), Poole-Frenkel (PF) emission (~ 4.8-7.3 MV/cm), and Fowler-Nordheim (FN) tunneling (~ 7.3-8.3 MV/cm) were the dominant current mechanisms under varying electric fields. At higher temperatures (75-100 °C), the leakage mechanism in Al-rich samples (50-100%) shifted from FN tunneling to PF emission at high electric fields (~ 3.3-6.87 MV/cm). The composition and energy band alignments of the films were characterized using X-ray photoelectron spectroscopy (XPS) and ultraviolet (UV) spectrophotometry, showing that introducing Al into HfO increases the bandgap, reduces the dielectric constant, and significantly lowers oxygen vacancies. Thus, it is further demonstrated that HfO films with the appropriate Al content can effectively enhance dielectric properties and adjust the material parameters of the dielectric layer.
通过等离子体增强原子层沉积（PEALD）在硅衬底上沉积了不同成分的(AlO)(HfO)薄膜，并制备了金属氧化物半导体（MOS）电容器。通过电学测量研究了不同诱导Al含量对HfO介电性能的影响。结果表明，增加Al含量会提高平带电压，降低界面态密度（D），并在给定电压下显著降低漏电流。此外，室温下的I-V测量表明，在不同电场下，肖特基发射（0.8 - 4.8 MV/cm）、普尔-弗伦克尔（PF）发射（4.8 - 7.3 MV/cm）和福勒-诺德海姆（FN）隧穿（7.3 - 8.3 MV/cm）是主要的电流机制。在较高温度（75 - 100°C）下，富Al样品（50 - 100%）在高电场（3.3 - 6.87 MV/cm）下的漏电流机制从FN隧穿转变为PF发射。使用X射线光电子能谱（XPS）和紫外（UV）分光光度法对薄膜的成分和能带排列进行了表征，结果表明将Al引入HfO会增加带隙，降低介电常数，并显著降低氧空位。因此，进一步证明了具有适当Al含量的HfO薄膜可以有效地增强介电性能并调整介电层的材料参数。
