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Electron Device Optimization

IP.com Disclosure Number: IPCOM000041249D
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Laibowitz, RB: AUTHOR [+3]

Abstract

The resistance or differential resistance of ultra-small (mesoscopic) structures can be adjusted by selective irradiation to alter the distribution of inherent scatterers, such as impurities, vacancy dislocations or surface irregularities.

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Electron Device Optimization

The resistance or differential resistance of ultra-small (mesoscopic) structures can be adjusted by selective irradiation to alter the distribution of inherent scatterers, such as impurities, vacancy dislocations or surface irregularities.

Ultra-small device structures, such as lines or rings of linewidths of 100nm, are made of metal chosen to yield a coarse approximation of the desired base resistance and magnetoresistance. Further refinement of these properties is done by altering the scattering sites. When the device size is generally smaller than the inelastic scattering length appropriate for the sample, a distribution of strong scatterers is present. That distribution can be changed by irradiation with a beam of focussed particles, as with an electron or ion beam. Irradiation can occur over all or part of the device and be done during measurement of the electrical properties of interest for precise adjustment. Scatterer distribution can also be changed by local stress or heat.

In mesoscopic rings, two magnetoresistance oscillations take place at frequencies differing by a factor of two (h/e)-I and (h/2e)-I . Altering the scatter site distribution changes the phase of the lower frequency. When magnetoresistance is measured directly or indirectly, the resistance or field sensitivity can be optimized by choosing the best scatterer distribution or phase relation between the two oscillations. Further control comes with changing speci...