Suppression of crack formation in wafer-scale amorphous SiNx films by residual hydrogen-ligands manipulation
Year: 2024
Type: article
Abstract: Plasma-Enhanced Chemical Vapor Deposition (PECVD) of amorphous silicon nitride (SiNx) thin films is a critical procedure in microelectronics serving as a surface passivation layer and dielectric barrier. However, intrinsic film stress continuously builds up along with PECVD growth, leading to film cracking. How to achieve crack-free PECVD amorphous SiNx film within a large thickness range remains a critical unresolved challenge in semiconductor industry. In this study, we revealed that high residual NH ligands from the NH3 precursor could induce excessive tensile strain at the SiNx/Si wafer interface and consequently aggravate SiNx film crack formation. With a heating pretreatment on the wafer, residual H ligands were effectively reduced to achieve homogenous chemical composition in SiNx film. As a result, the crack number declined ∼42% and the remaining crack length was substantially shorter in contrast to the original SiNx film. This work demonstrates the crucial role of residual ligands on internal strain regulation and points out a pathway to achieve crack-free PECVD SiNx films in industrial manufacturing.
Source: Nano Trends
Authors: Yutao Dong, Xin Yin, Wenjian Liu, Fayaz A. Shaikh, Ziyi Zhang, Xudong Wang
Institutions: University of Wisconsin–Madison, Lam Research (United States)
Language: English
Subfield: Mechanics of Materials
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,000
Award: G1427113850
OpenAlex ID: W4400016036