Simultaneous Determination of Young's Modulus and Density of Ultrathin Low‐k Films Using Surface Acoustic Waves
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2024-02-20 |
| Journal | physica status solidi (a) |
| Authors | Li Zhang, Xia Xiao, Jinsong Zhang, Zhuo Liu, Yiting Huang |
| Institutions | Tianjin University |
Abstract
Section titled “Abstract”The nondestructive testing (NDT) of mechanical properties in ultrathin low dielectric constant (low‐ k ) films is a major challenge in integrated circuit manufacturing. Young’s modulus and density are closely related parameters for low‐ k films. This study presents a method for NDT of Young’s modulus and density of porous low‐ k black diamond (SiOC:H, BD) films. A linear frequency modulation (LFM) surface acoustic wave (SAW) interdigital transducer (IDT) with a frequency range of 20-250 MHz is designed to generate SAW signals on the samples. The series of SAW waveforms obtained on the samples are processed to obtain experimental SAW dispersion curves across a broad frequency range. By comparing these experimental curves with theoretical dispersion curves, as well as their first‐order derivatives, Young’s modulus and density of porous low‐ k BD films with thicknesses of 100, 300, 500, and 1000 nm are characterized. To verify Young’s modulus measurements from the SAW method, a control experiment using nanoindentation is conducted. The results demonstrate that the SAW method can reduce the impact of the substrate and is independent of the film thickness. This study presents a highly accurate measuring method for simultaneous multiparameter evaluation of ultra‐thin low‐ k films.