Structure and Dielectric Property of High-k ZrO2 Films Grown by Atomic Layer Deposition Using Tetrakis(Dimethylamido)Zirconium and Ozone

• Main Authors: Junqing Liu, Junpeng Li, Jianzhuo Wu, Jiaming Sun
• Format: Article
• Language: English
• Published: SpringerOpen 2019-05-01
• Series: Nanoscale Research Letters
• Subjects: Atomic layer deposition; ZrO2; Electrical property; Thermal annealing
• Online Access: http://link.springer.com/article/10.1186/s11671-019-2989-8

Abstracts High-k metal oxide films are vital for the future development of microelectronics technology. In this work, ZrO2 films were grown on silicon by atomic layer deposition (ALD) using tetrakis(dimethylamido)zirconium and ozone as precursors. The relatively constant deposition rate of 0.125 nm/cycle is obtained within the ALD temperature window of 200–250 °C. The film thickness can be precisely controlled by regulating the number of ALD cycle. The ZrO2 films formed at 200–250 °C have an O/Zr atomic ratio of 1.85–1.9 and a low content of carbon impurity. ZrO2 film begins to crystallize in ALD process above 210 °C, and the crystal structure is changed from cubic and orthorhombic phases to monoclinic and orthorhombic phases with increasing the deposition temperature to 350 °C. Moreover, the effect of annealing temperature on dielectric properties of ZrO2 film was studied utilizing ZrO2-based MIS device. The growth of the interface layer between ZrO2 and Si substrate leads to the decrease in the capacitance and the leakage current of dielectric layer in the MIS device after 1000 °C annealing. ZrO2 film exhibits the relatively high dielectric constant of 32.57 at 100 kHz and the low leakage current density of 3.3 × 10−6 A cm−2 at 1 MV/cm.