DC substrate bias enables preparation of superior-performance TiN electrode films over a wide process window. (November 2019)

• Record Type: Journal Article
• Authors: Sun, Nana; Zhou, Dayu; Shi, Shuyan; Liu, Wenwen; Zhao, Xiuming; Liu, Feng; Tian, Zhongjie; Li, Shuaidong; Wang, Jingjing; Ali, Faizan
• Is Part Of: Materials research bulletin. Volume 119(2019)
• Publication Date: 2019-11
• Subjects: A. Nitrides -- A. Thin films -- B. Sputtering -- B. Microstructure -- C. Atomic force microscopy -- C. Electron microscopy -- C. X-ray diffraction -- D. Crystal structure -- D. Electrical properties; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2019.110575
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: Highlights: The effects of deposition parameters on the properties of TiN films were studied in detail. The lowest resistivity of 31 μΩ · cm is achieved with a DC bias voltage of −150 V. A suitable substrate bias enables growth of smooth TiN films with low resistivity in working pressure range of 0.3–1.1 Pa. A suitable substrate bias enables growth of smooth TiN films with low resistivity in temperature range from RT to 350 °C. Abstract: When stacking with various underlying layers in the microelectronics devices, titanium nitride electrode films are not only desired to meet the critical requirements for high conductivity and low surface roughness, but also to be deposited over a wide processing window. In this work, a negative substrate bias was introduced as an additional power for the reactive sputtering of titanium nitride films. Upon systematically adjusting the substrate bias, working pressure and substrate temperature, the evolution of film properties was studied in detail in terms of resistivity, growth rate, crystal structure, surface morphology and composition. It was shown that an optimized substrate bias is beneficial for film densification and grain reorientation. As a result, titanium nitride films with superior-performance (resistivity ≤ 53.2 μΩ·cm and surface roughness ≤0.66 nm) can be grown over a wide working pressure range of 0.3–1.1 Pa and substrate temperature range from room temperature to 350 °C.