Temperature Enhanced Large Area Nano Transfer Printing on Si/SiO₂Substrates Using Si Wafer Stamps

Metal nano structures on various substrates such as Si wafers, SiO2 surfaces, or glass are of great importance on a variety of devices.The state of the art fabrication methods like optical and electron beam lithography are wet, complex, and costly processes. Nano transfer printing (nTP) canprovide a simple, fast, and low cost alternative. In the nano transfer process, thin metal layers are deposited on a stamp and transferred by pressing the stamp on the substrate. In this study, we focus on the interface between the transferred metals and the substrate. A high adhesion can be achieved by forming silanols on the substrate surface and hydroxyl groups on the metal one. When the metal and substrate surfaces are pressed against one another, reversible metal-oxygen-silicon bonds are generated and water is formed. The nTP is strongly improved when water is removed by applying temperatures of around 200°C (390°F). Large area nano transfer printing of metal structures consisting of gold, aluminum, or magnetic Permalloy™ is demonstrated.