Detection of a single-charge defect in a metal-oxide-semiconductor structure using vertically coupled Al and Si single-electron transistors

Abstract

An Al-AlO_x-Al single-electron transistor (SET) acting as the gate of a narrow (~ 100 nm) metal-oxide-semiconductor field-effect transistor (MOSFET) can induce a vertically aligned Si SET at the Si/SiO_2 interface near the MOSFET channel conductance threshold. By using such a vertically coupled Al and Si SET system, we have detected a single-charge defect which is tunnel-coupled to the Si SET. By solving a simple electrostatic model, the fractions of each coupling capacitance associated with the defect are extracted. The results reveal that the defect is not a large puddle or metal island, but its size is rather small, corresponding to a sphere with a radius less than 1 nm. The small size of the defect suggests it is most likely a single-charge trap at the Si/SiO_2 interface. Based on the ratios of the coupling capacitances, the interface trap is estimated to be about 20 nm away from the Si SET.

5 pages and 5 figures

References in corpus (5)

• Transport spectroscopy of a single dopant in a gated silicon nanowire
• Is charge noise in single electron transistors and charge qubits caused by metallic grains?
• Electric-field-dependent spectroscopy of charge motion using a single-electron transistor
• Electron spin blockade and singlet-triplet transition in a silicon single electron transistor
• Coulomb blockade in a Si channel gated by an Al single-electron transistor

Cited by in corpus (3)

• Electron tunnel rates in a donor-silicon single electron transistor hybrid
• Waiting time distributions in a two-level fluctuator coupled to a superconducting charge detector
• Detection of variable tunneling rates in silicon quantum dots