Adhesion Comparison of Low Dielectric Constant Thin Films Using Four Point Bend and Nanoscratch Testing

• Main Author: Vilceus, Daniel
• Format: Others
• Published: Scholar Commons 2008
• Subjects: Epoxy; Fracture; Hardness; Modulus; Notch; silicon; American Studies; Arts and Humanities
• Online Access: https://scholarcommons.usf.edu/etd/547; https://scholarcommons.usf.edu/cgi/viewcontent.cgi?article=1546&context=etd

As the semiconductor technology moves further into scaled down device structures, modern day complexities in the fabrication processes become more prevalent. This thesis focuses on the issues associated with mechaincal and adhesion failure in low dielectric constant (low-k) thin films. In this thesis the four point bend test and nanoscratch test method was used for evaluating adhesion of boro-phosphate-silicate glass (BPSG) and tetraethylorthosilicate (TEOS) low-k thin films to silicon subtrates. Nanoindation tests were also performed on the low-k films to evaluate material properties such as hardness and elastic modulus. The sample preparation and testing set up for the four point bend test and nanoscratch test were observed to be greatly disparate. Nanoscratch and nanoindentation sample preparation and sample testing were able to be carried out much quicker than in four point bending. It was observed that nanoscratch testing holds an immense potential for reducing the time needed to evaluate thin film adhesion then in FPB testing. Nanoindentation performed on the BPSG and TEOS dielectric thin films showed uniform mechinacal properties throughout the surface of the films. The adhesion energy for BPSG and TEOS using FPB testing ranged from 29.5390 J/m² - 3.0379 J/m². While the adhesion energy for BPSG and TEOS using nanoscratch testing ranged from 0.0012 J/m² - 0.0028 J/m². It was observed that the difference in adhesion energy for FPB and nanoscratch testing was due to differing failures modes.