Transmission line measurement


Transmission line measurement

Transmission line measurement or Transfer Length Measurement is a technique used in semiconductor physics and engineering to determine the contact resistance between a metal and a semiconductor. The technique involves making a series of metal-semiconductor contacts separated by various distances. Probes are applied to pairs of contacts, and the resistance between them is measured by applying a voltage across the contacts and measuring the resulting current. The current flows from the first probe, into the metal contact, across the metal-semiconductor junction, through the sheet of semiconductor, across the metal-semiconductor junction again (except this time in the other direction), into the second contact, and from there into the second probe and into the external circuit to be measured by an ammeter. The resistance measured is a linear combination (sum) of the contact resistance of the first contact, the contact resistance of the second contact, and the sheet resistance of the semiconductor in-between the contacts.

If several such measurements are made between pairs of contacts that are separated by different distances, a plot of resistance versus contact separation can be obtained. Such a plot should be linear, with the slope of the line being the "sheet resistance" in ohms per centimeter or ohms per meter. The intercept of the line with the y-axis, is two times the contact resistance. Thus the sheet resistance as well as the contact resistance can be determined from this technique.


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Transmission line — This article is about the radio frequency transmission line. For the power transmission line, see electric power transmission. In communications and electronic engineering, a transmission line is a specialized cable designed to carry alternating… …   Wikipedia

  • Single-wire transmission line — A single wire transmission line (or single wire method) is a method of supplying electrical power through a single wired electrical conductor. Single wire earth return (SWER) or single wire ground returns today supply single phase electrical… …   Wikipedia

  • Measurement microphone calibration — In order to take a scientific measurement with a microphone, its precise sensitivity must be known (in volts per Pascal). Since this may change over the lifetime of the device, it is necessary to regularly calibrate measurement microphones. This… …   Wikipedia

  • Line-of-sight propagation — refers to electro magnetic radiation including light emissions traveling in a straight line. The rays or waves are diffracted, refracted, reflected, or absorbed by atmosphere and obstructions with material and generally cannot travel over the… …   Wikipedia

  • Measurement while drilling — Well logging Gamma ray logging Spontaneous potential logging Resistivity logging Density logging Sonic logging Caliper logging Mud logging LWD/MWD v · …   Wikipedia

  • Acoustic transmission lines — An acoustic transmission line is the acoustic analog of the electrical transmission line, typically thought of as a rigid walled tube that is long and thin relative to the wavelength of sound present in it. Pipe organs, woodwinds, and the like… …   Wikipedia

  • Speech transmission index — Speech Transmission Index, short STI is a measure of speech transmission quality. The absolute measurement of speech intelligibility is a complex science. The STI measures some physical characteristics of a transmission channel (a room, electro… …   Wikipedia

  • Electric Line — The term wireline usually refers to a cabling technology used by operators of oil and gas wells to lower equipment or measurement devices into the well for the purposes of well intervention and reservoir evaluation. Braided line can contain an… …   Wikipedia

  • Flow measurement — is the quantification of bulk fluid movement. Flow can be measured in a variety of ways. Positive displacement flow meters acumulate a fixed volume of fluid and then count the number of times the volume is filled to measure flow. Other flow… …   Wikipedia

  • Motorcycle testing and measurement — A Triumph Sprint ST on a chassis dynamometer …   Wikipedia


We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.