Wong Hei, Li Weidong, Zhang Jieqiong, Liu Jun
Department of Electrical Engineering, City University of Hong Kong, Hong Kong, China.
Yangtze Memory Technologies Co., Ltd., East Lake High-Tech Development Zone, Wuhan 430078, China.
Nanomaterials (Basel). 2025 Jun 21;15(13):963. doi: 10.3390/nano15130963.
By embedding an aluminum-laminated layer within LaO thin films and subjecting them to high-temperature rapid thermal annealing, a LaO/LaAlO/LaO sandwich dielectric was formed. This structure enhances the interface properties with both the silicon substrate and the metal gate electrode, improving current conduction. Comprehensive analysis using X-ray Photoelectron Spectroscopy (XPS) revealed that this novel process not only facilitates the formation of a high-quality lanthanum aluminate layer, as indicated with Al 2p peak at 74.5 eV, but also effectively suppresses silicate layer growth, as supported by the weak Si-O signal from both the Si 2s (153.9 eV) and O 1s (533 eV) peaks at the dielectric/Si interface in the Al-laminated samples. Fourier Transform Infrared (FTIR) spectroscopy revealed a significant reduction in the OH absorption peak at 3608 cm OH-related band centered at 3433 cm. These improvements are attributed to the aluminum-laminated layer, which blocks oxygen and hydroxyl diffusion, the LaAlO layer scavenging interface silicon oxide, and the consumption of oxygen during LaAlO formation under thermal annealing. Electrical measurements confirmed that the dielectric films exhibited significantly lower interface and oxide trap densities compared to native LaO samples. This approach provides a promising method for fabricating high-quality lanthanum-based gate dielectric films with controlled dielectric/substrate interactions, making it suitable for nano-CMOS and memristive device applications.
通过在氧化镧（LaO）薄膜中嵌入铝层并对其进行高温快速热退火，形成了LaO/LaAlO/LaO三明治电介质。这种结构增强了与硅衬底和金属栅电极的界面特性，改善了电流传导。使用X射线光电子能谱（XPS）进行的综合分析表明，这种新工艺不仅促进了高质量铝酸镧层的形成，如74.5 eV处的Al 2p峰所示，而且有效地抑制了硅酸盐层的生长，这在含铝层样品的电介质/硅界面处Si 2s（153.9 eV）和O 1s（533 eV）峰的微弱Si - O信号中得到了证实。傅里叶变换红外（FTIR）光谱显示，在3608 cm处的OH吸收峰以及以3433 cm为中心的OH相关带显著降低。这些改进归因于铝层，它阻止了氧和羟基的扩散；LaAlO层清除了界面氧化硅；以及在热退火过程中LaAlO形成时氧的消耗。电学测量证实，与原生LaO样品相比，电介质薄膜表现出显著更低的界面和氧化物陷阱密度。这种方法为制造具有可控电介质/衬底相互作用的高质量镧基栅电介质薄膜提供了一种有前景的方法，使其适用于纳米CMOS和忆阻器器件应用。
