Simplified MOS Quantum Dots for Materials Characterization

Using single-layer metal gate patterns, metal-oxide-semiconductor (MOS) quantum dot devices with charge sensors are fabricated and measured as a simplified approach to developing more rigorous qualifying metrics than transport for materials and interfaces. Materials and interfaces are often identified as sources of charge traps and time instabilities difficult to assess with transport techniques, and the ability to form quantum dots and charge sense in these systems enables charge offset drift and, potentially, spin relaxation measurements to critically assess the feasibility of the materials and methods for use in qubit applications. Various multiple-dot designs with charge sensors have been fabricated, and the tunability and charge offset stability of these devices will be discussed in the context of developing tools for qualifying materials for quantum.