Kalinin Ivan A, Roslyakov Ilya V, Khmelenin Dmitry N, Napolskii Kirill S
Department of Materials Science, Lomonosov Moscow State University, 119991 Moscow, Russia.
Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
Nanomaterials (Basel). 2022 Dec 25;13(1):94. doi: 10.3390/nano13010094.
Microheaters with long-term stability are crucial for the development of a variety of microelectronic devices operated at high temperatures. Structured Ta/Pt bilayers, in which the Ta sublayer ensures high adhesion of the Pt resistive layer, are widely used to create microheaters. Herein, a comprehensive study of the microstructure of Ta/Pt films using high-resolution transmission electron microscopy with local elemental analysis reveals the twofold nature of Ta after annealing. The main fraction of Ta persists in the form of tantalum oxide between the Pt resistive layer and the alumina substrate. Such a sublayer hampers Pt recrystallization and grain growth in bilayered Ta/Pt films in comparison with pure Pt films. Tantalum is also observed inside the Pt grains as individual Ta nanoparticles, but their volume fraction is only about 2%. Microheaters based on the 10 nm Ta/90 nm Pt bilayers after pre-annealing exhibit long-term stability with low resistance drift at 500 °C (less than 3%/month).
具有长期稳定性的微型加热器对于各种在高温下运行的微电子器件的发展至关重要。结构化的Ta/Pt双层膜，其中Ta子层确保了Pt电阻层的高附着力，被广泛用于制造微型加热器。在此，使用具有局部元素分析功能的高分辨率透射电子显微镜对Ta/Pt薄膜的微观结构进行的全面研究揭示了退火后Ta的双重性质。Ta的主要部分以氧化钽的形式存在于Pt电阻层和氧化铝衬底之间。与纯Pt薄膜相比，这样的子层阻碍了双层Ta/Pt薄膜中Pt的再结晶和晶粒生长。在Pt晶粒内部也观察到钽以单个Ta纳米颗粒的形式存在，但其体积分数仅约为2%。预退火后的基于10 nm Ta/90 nm Pt双层膜的微型加热器在500°C下表现出长期稳定性，电阻漂移低（小于3%/月）。
