Electrical Characteristics and Reliability of SiCN/Porous SiOCH Stacked Dielectric: Effects of Deposition Temperature of SiCN Film

Abstract

Silicon carbonitride (SiCN) films deposited using silazane singe-precursor with different temperatures were capped onto porous carbon-doped silicon oxide (p-SiOCH) dielectric films. Effects on the electrical and reliability characteristics of the fabricated SiCN/p-SiOCH stacked dielectrics were investigated. Experimental results indicated that increasing the deposition temperature of the SiCN film increased barrier capacity against Cu migration under thermal and electrical stress and time-dependence-dielectric-breakdown reliability for the SiCN/p-SiOCH stacked dielectric. Therefore, this study provides a promising processing to deposit a SiCN barrier by elevating the deposition temperature and using N-methyl-aza-2,2,4-trimethylsilacyclopentane singe-precursor, which can be applied to back-end-of-line interconnects for advanced technological nodes in the semiconductor industry. A larger capacitance, however, is the main issue due to a larger intrinsic dielectric constant of the SiCN film and stronger plasma-induced damage on the p-SiOCH film. As a result, the related actions will be taken in the future research to improve this issue.

Chemical Structure, Optical and Dielectric Properties of PECVD SiCN Films Obtained from Novel Precursor

“…The chemical bonding structure and composition of the films define their functional characteristics; it is most clearly expressed for non-stoichiometric compounds, like silicon carbonitride. Depending on the elemental composition, SiCN films possesses a set of properties that make them attractive as materials for different applications, such as different layers in modern semiconductor electronics [2][3][4], hard and protective coatings [5,6], piezoresistive material for pressure sensors [7], passivation and antireflective coatings for silicon solar cells [8], coatings in optoelectronics [9,10], etc.…”

“…Recently, studies have appeared devoted to the study of the effect of the phenyl group of the precursor on the structure and properties of silicon-based films. In [34] the films with the small pore size with narrow distribution were formed in benzene-bridged structure using (EtO) 3 Si -C 6 H 4 -Si(OEt) 3 . The films possessed improved mechanical and dielectric properties.…”