Formation of silicon carbide defect qubits with optically transparent electrodes and atomic layer deposited silicon oxide surface passivation

Defect qubits in silicon carbide are an emerging system for quantum information science and technology. It is important to passivate and protect the surface to preserve the particular defect configurations as well as to provide means to tune the opto-electronic properties via electronic or opto-electronic gating. In this work, we construct defect qubit device structures that integrate Indium-Tin-Oxide (ITO) electrodes and a thin atomic layer deposited (ALD) silicon-oxide surface passivation. The devices are formed via 12C ion implantation and high temperature annealing of 4H and 6H silicon carbide. The process involves the integration of optically transparent indium tin oxide electrodes and a surface passivation film of silicon-oxide by atomic layer deposition. We find good contact is formed between ITO and SiC, and after complete processing, the measured broad-band photoluminescence (PL) with excitation at 785 nm in a scanning PL system is consistent with the formation of silicon vacancies. We find minimal change in the room temperature emission in regions beneath the ITO electrodes and the SiOx-SiC passivated surface. We evaluate the ability of an electric field to tune the optically detected magnetic resonance (ODMR) response of the qubit system by simulations of the spectrum with a modified spin Hamiltonian that considers the Stark Effect. We quantify the simulated strength of the electric-field tuning of the energy levels and ODMR response for the various identified spin 3/2 transitions of the silicon vacancy.