AlNi Multilagen

Thermomechanical stress and deformation effects in reactive Al/Ni multilayers for de-bonding

Contact person

Prof. Peter Schaaf
Group of Materials for Electricial Engineering and Electronics

Phone: +49 3677 69-3611

Funding information

Project leader: Deutsche Forschungsgemeinschaft 

Project number: SCHA 632/9-2

Participating groups: Group of Materials for Electrical Engineering and Electronics, Electronics Technology Group

Period of funding: 01.10.2023 - 30.09.2025


The first phase of the project was concerned with determining the effects of mechanical and thermomechanical stresses on the transformation reaction and phase formation in reactive Ni/Al multilayer systems (RMS). This included both intrinsic and extrinsic stresses resulting from mechanical loading as well as stresses caused by geometrical limitations such as passivation layers. So far, it has been shown that extrinsically applied stresses have no significant influence on the reaction behavior of the Al/Ni reactive multilayer system (RMS) and its phase formation. However, the investigations show that cracking or delamination of the reactive multilayer system occurs after or during the reaction with certain substances, especially on single-crystal silicon. In addition, the reaction rate and temperature were changed as a result. Therefore, the intrinsic thermomechanical stresses during and after the reaction are much more important than the extrinsic stresses. The next phase of the project will take these intrinsic stresses into account and aims to utilize these intrinsic stresses for selective delamination of the layers "at the push of a button". For this purpose, the corresponding thermomechanical properties must be further characterized and tailored for debonding processes. Debonding and delamination applications are of great importance for dismantling and recycling in the field of microsystems technology. Individual components are difficult or uneconomical to separate from the overall system, which severely impairs sustainability and the circular economy (conservation of resources). In the field of application, the integration of the RMS into a microelectronic system will be necessary. In addition to voltage-induced delamination, detailed investigations into long-term stability are necessary ...