Surface roughness effect on copper–alumina adhesion

• Published in: Microelectronics and reliability Vol. 53; no. 9-11; pp. 1548 - 1552
• Main Authors: Lim, Ju Dy, Susan, Yeow Su Yi, Daniel, Rhee MinWoo, Leong, Kam Chew, Wong, Chee Cheong
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier Ltd 01.09.2013; Elsevier
• Subjects: ADHESION; ADHESIVE BONDING; Adhesive strength; Alumina; ALUMINUM OXIDE; Atomic force microscopy; BONDING; Bonding strength; Condensed matter: structure, mechanical and thermal properties; Contact; Copper; COPPER (PURE); DEPOSITION; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Mechanical and acoustical properties; Mechanical contact (friction...); Physical properties of thin films, nonelectronic; Physics; Solid mechanics; Structural and continuum mechanics; Surface area; SURFACE FINISH; Surface roughness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Bonding strength; Surface roughness; Copper; Surface area; Alumina; Atomic force microscopy; Roughness; Rough surfaces; Adhesion; Oxide ceramics; Contact surface; Interfaces; Metal coating; Adhesive strength; Modelling; Mechanical contacts
• ISSN: 0026-2714; 1872-941X
• DOI: 10.1016/j.microrel.2013.07.016

•We have examined the alumina substrate with three different surface roughness and compare their adhesive strength.•We have estimated the surface area based on these surface roughness using AFM 2D model.•Area in contact increases with surface roughness.•Bonding strength at the interface increases with surface roughness.•Increment of bonding strength is mainly due to the area in contact. The surface roughness of the substrate itself could play an important role for the bonding at the interface. In this paper, a correlation of the surface roughness of a rigid alumina substrate and its 2D model of estimated surface area has been studied using Atomic Force Microscopy (AFM). With rougher surface, the adhesive strength between a deposited copper film and the alumina substrate is higher due to the larger contact area at the interface. For 99.99% pure copper–96% pure alumina, this effect can account for an adhesive strength increment of more than 50%.