A Parallel Single-Electron Box Array Scanning Probe

The coupling of scanning microscopy and contact potential difference (CPD) measurements has enabled a wide range of surface characterization capabilities, such as the identification of dopants in a material, mapping of the charge distribution of a sample, and the imaging of the band bending of semiconductors. The two most common scanning CPD methods to date are electrostatic force microscopy (EFM) and Kelvin force probe microscopy (KFPM). These two methods, however, require relatively large potentials between the tip and the sample (1-3 V for KFPM). Such large potentials can distort the charge distribution of the surface to be measured. The method proposed in this dissertation work will be to implement a scanning microscope using single-electron boxes (SEBs) as the primary charge/potential sensor, as opposed to tip-sample interactions used in EFM and KFPM. SEBs operate at very small biases (typically < 1 mV) and are very sensitive to charge and voltage fluctuations. For these reasons, implementing a scanning SEB (S-SEB) probe can work around the high bias conditions required by EFM and KFPM. In this dissertation work, a high-resolution, high-sensitivity S-SEB has been designed and fabricated by implementing parallel SEBs with large charging energy (~ 10 meV), measured using radio-frequency reflectometry, and using a silicon nitride membrane tip.