基底偏压对 Zr-B-O-N 薄膜结构及性能的影响

Zirconium diboride(ZrB₂) thin films possess high melting point and low resistivity, and has a wide application potential in Cu interconnection of silicon based devices. However, the deposited ZrB₂ films usually show crystal structure, and its grain boundary provides a fast diffusion path for Cu atoms. Amorphous structure can be obtained by doping nonmetallic elements (N or O atoms) to improve its diffusion barrier performance. In this paper, Zr-B-O-N films were deposited on single crystal Si (100) substrates by reactive magnetron sputtering under different substrate bias voltages. The microstructure, electrical and diffusion barrier performance of the films were characterized by atomic force microscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy and four point probe. The results show that the deposited Zr-B-O-N films are amorphous and have flat surface, the roughness increases with the increase of substrate bias voltage. When the substrate bias voltage is 150 V, the formed amorphous Zr-B-O-N film with a thickness of 10 nm can effectively block Cu atom diffusion at 700 ℃. Therefore, Zr-B-O-N film is a kind of potential diffusion barrier materials in the future.