Printer for the ultraflat contacting of integrated circuits and 3D metalizations

• Subject Area: Electrical Engineering and Information Technology
• Term: Funded in 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 538860329

This proposal aims at the procurement of a system ("printer") for the additive manufacturing of low-inductance and ultra-flat chip contacts as well as passive electrical structures ("metallizations") on two- and three-dimensional surfaces. In the current state of the art, packaging and interconnect technology often represents the bottleneck for miniaturization of high-performance quantum systems. An important limitation is often the minimal length as well as the parasitic inductance of conventional electrical contacts using wire bonds. The requested device allows a significant reduction of the minimum height of the contacts down to a few micrometers as well as a significant reduction of the connection length, which correlates one-to-one with the parasitic inductance. Since the requested device enables printing of the contacting as well as the coil/resonator structures needed for spin-based qubits in one go, parasitic inductances between coil/resonator and the chip of a few 100 pH can be achieved, enabling direct driving of the coil/resonator without the 50 Ω matching typically used. Direct injection of current into the coil structure is thereby significantly more energy efficient, enabling significant power dissipation savings in future integrated spin-based quantum systems. In addition, the proposed device enables the metallization of arbitrary three-dimensional geometries, which will be used to fabricate three-dimensional coils and resonators. Such three-dimensional microcoils and microresonators exhibit significantly better homogeneity of the generated high-frequency magnetic fields compared to planar geometries. RF or microwave magnetic fields of high homogeneity are a basic requirement for almost all modern pulsed control sequences for spin qubits. The 3D coils or resonators can be manufactured in the first step by means of e.g. a 3D-printed mold and the requested device. In the second step, the driving ICs are placed next to the resonator/coil using pick-and-place, and then in the final third step, again using the requested device, the electrical contact with low insertion inductance between IC and resonator/coil is established. In this way, integrated quantum systems can be realized which improve the state of the art in terms of performance and energy efficiency and will also allow a future production in medium quantities. Overall, the requested device will be used for research into new concepts for increasing the performance and miniaturizability of quantum sensors by means of hybrid microintegration.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Drucker für ultraflache Chipkontaktierungen und 3D-Metallisierungen (Teilfinanzierung)
• Instrumentation Group: 2110 Formen-, Modellherstellung und gießereitechnische Maschinen
• Applicant Institution: Universität Stuttgart
• Leader: Professor Dr. Jens Anders