Printed array of thin-dielectric metal-oxide-metal (MOM) tunneling diodes

A large area array of metal-oxide-metal (MOM) tunneling diodes with an ultrathin dielectric (∼3.6 nm aluminum oxide) have been fabricated via a transfer-printing process. The MOM diodes exhibit an excellent tunneling behavior that is suitable for rectifying high-frequency ac current into direct current (dc). Direct tunneling and Fowler-Nordheim tunneling have been observed over eight orders of magnitude in current density. The ratio between forward and reverse current is as large as two orders of magnitude. Simulations have been carried out to extract the static device parameters and have confirmed the existence of a dipole layer at the aluminum/aluminum oxide interface of the printed tunneling diodes. Capacitance measurements have shown that the permittivity of the ultrathin aluminum oxide film is smaller than that of bulk aluminum oxide. The mechanical yield of the transfer-printing process is better than 80%, confirming that transfer printing is a promising candidate for the efficient fabrication of quantum devices over large areas.