Accession Number : ADA294853

Title :   Fabrication Technology and Measurement of Coupled Quantum Dot Devices.

Descriptive Note : Final rept. 1 Nov 91-31 Jan 95,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF ELECTRICAL ENGINEERING AND COMPU TER SCIENCE

Personal Author(s) : Antoniadis, Dimitri A. ; Smith, Henry I. ; Burkhardt, Martin

PDF Url : ADA294853

Report Date : 31 JAN 1995

Pagination or Media Count : 170

Abstract : This report describes the fabrication and measurement of planar tunneling devices. X-ray lithography was used to define gate patterns in order to achieve lateral electrostatic confinement in a two dimensional electron gas. Technologies were developed for the printing of features with linewidth of 50 nm and below, a lithographic resolution which is necessary for the fabrication of narrow tunneling barriers. Development of technologies such as this can also be used for large scale fabrication of silicon and GaAs devices and circuits with critical dimensions of 100 nm and below. Quantum dots in which the capacitances to the dot were minimized, were fabricated using high resolution lithography. Decreased capacitances to the dot increase the charging energy of a quantum dot, making it possible to observe single electron effects at elevated temperatures. The conductance of a device, featuring eight electrodes to control size and shape of a quantum dot, was measured in a Heliox insertion probe at a temperature of 300 mK. Measurements of several quantum dot sizes were performed and the results were discussed. The same device was biased to produce two unequal quantum dots in series. The results are discussed and compared with theoretical predictions.

Descriptors :   *TUNNELING(ELECTRONICS), *GATES(CIRCUITS), *QUANTUM ELECTRONICS, COUPLING(INTERACTION), CONTROL, TWO DIMENSIONAL, GALLIUM ARSENIDES, THEORY, FABRICATION, ELECTRON GAS, HIGH RESOLUTION, X RAYS, LITHOGRAPHY, ELECTRONS, ELECTRODES, SILICON, PLANAR STRUCTURES, BARRIERS, PATTERNS, CAPACITANCE.

Subject Categories : Electricity and Magnetism
      Quantum Theory and Relativity

Distribution Statement : APPROVED FOR PUBLIC RELEASE