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Contactless, High-Speed Electronic Sampling Probe

IP.com Disclosure Number: IPCOM000037907D
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2005-Jan-30
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Faris, SM: AUTHOR [+4]

Abstract

A vacuum tunneling probe may be used for the sampling of electrical transients.

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This is the abbreviated version, containing approximately 69% of the total text.

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Contactless, High-Speed Electronic Sampling Probe

A vacuum tunneling probe may be used for the sampling of electrical transients.

The sampling device consists of a metal tip in close proximity to an electrical conductor in which the transient propagates. An optical pulse incident on this metal-vacuum-metal tunneling junction is rectified by nonlinearities in the current- voltage characteristic of the junction. The coincidence of electrical and optical pulses changes the junction response, thereby providing a cross-correlation of the pulses. By varying the delay between the pulses, the complete cross- correlation is obtained. This vacuum tunneling junction is expected to have a frequency response better than 200 THz (5 fs). The contactless probe may also be laterally scanned in order to probe different parts of the circuit. With a scan length of the order of microns, it is possible to look for inhomogeneities and defects of individual elements in an integrated circuit.

The sampler is shown schematically in the drawing. A dc tunneling current ib produced by a dc voltage bias is used to maintain a constant tip-sample separation. Electrical pulses at the junction will effectively change the bias, producing a current ie . Optical pulses will be rectified by the nonlinearities of the junction producing a current io . Because the nonlinear properties of the junction depend on the bias, coincident optical and electrical pulses will produce an additional component ioe of...