Title :
Sub-micron field-effect transistor using granular NbN thin films
Author :
Zhang, L. ; Yoshikawa, N. ; Sugahara, M.
Author_Institution :
Fac. of Eng., Yokohama Nat. Univ., Japan
fDate :
3/1/1993 12:00:00 AM
Abstract :
The conductance modulation induced by an electrostatic field is observed in highly resistive NbN granular thin films at low temperatures. The measurement is performed using a three-terminal device with FET structure, whose channel is made of NbN thin films. The field effect is interpreted based on the single electron charging effect of small intergrain junctions. The submicron-size channel (0.5 mu m) is fabricated by using the electron-beam lithography technique. The conductance modulation is found to be enhanced by the reduction of the channel size. In order to assess the feasibility of the FET using FET phenomena, the gate voltage dependence of the I-V curve and of the conductance of the channel part is examined. The charging effect is discussed on the basis of a one-dimensional array model of the small tunnel junctions.<>
Keywords :
electron beam lithography; field effect transistors; niobium compounds; superconducting junction devices; superconducting thin films; superconductive tunnelling; type II superconductors; 0.5 micron; I-V curve; conductance modulation; electron-beam lithography; electrostatic field; field-effect transistor; gate voltage dependence; granular NbN thin films; highly resistive NbN; low temperatures; one-dimensional array model; single electron charging effect; small intergrain junctions; small tunnel junctions; sub micron FET; submicron-size channel; three-terminal device; Circuits; Electrodes; Electrons; FETs; Granular superconductors; Superconducting films; Superconducting transition temperature; Thermal resistance; Thin film transistors; Tunneling;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
