Adhesion analysis of silane coupling agent/copper interface with density functional theory

Abstract

Nanotechnology devices with strong adhesion strength are required due to the miniaturization and reduction of the thickness of electronic devices. This paper describes a technique to select a silane coupling agent effective for obtaining the strong adhesion with copper by use of a density functional theory (DFT) in addition to an experimental peel test. We calculated the adhesion energy at the interface between three candidate silane coupling agents, aminoethyl-aminopropyltrimethoxysilane (AEAPS), mercaptopropyltrimethoxysilane (MPS), and aminopropyltrimethoxysilane (APS), and the copper in order to evaluate the adhesion strength at the interface. The adhesion energy obtained from DFT simulations increased in the order of AEAPS/copper > MPS/copper >APS/copper. The peel strength obtained from an experimental peel test increased in the same order as the adhesion energy obtained from the DFT simulation. Thus, AEAPS was selected as an effective coupling agent for obtaining the strong adhesion with copper. The selection method with the DFT simulation in addition to a peel test is considered to be effective for selecting the best material with the highest adhesion strength.