Bachelor defense by Nanna Schwarz Jørgensen

Optimization of nanofabrication and structural characterization: Towards data driven research

Abstract:
Decoherence due to environmental interactions emerge as a main obstacle when realizing a scalable quantum computer. Here, an optimization of quantum circuit fabrication protocols is investigated by examining the curing and removal of E-beam resist on aluminum substrates. Two screening design of experiments (DOEs) were formulated to identify the process control parameters (PCPs) most impactful in the fabrication of quantum resonator devices. The results were analysed by implementing atomic force microscopy (AFM) and subsequent data analysis. In particular, the curing process of the applied resist emerged as a central PCP in optimizing the fabrication protocol prebaking at 185C provided results of significantly lower quality than both a 115\degree C prebake and vacuum pumping as curing methods. N-methyl-2-pyrrolidone (NMP) and sonication also contributed to improved structural cleanliness. The best results were not fully reproducible, indicating that uncontrolled PCPs still affect the performance.