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Voltage Measurement in Semiconductor Device by Electron Beam

IP.com Disclosure Number: IPCOM000083943D
Original Publication Date: 1975-Aug-01
Included in the Prior Art Database: 2005-Mar-01
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Herman, PA: AUTHOR [+3]

Abstract

In the circuit device that is shown schematically, a voltage is to be measured at a point PM by an electron-beam technique. When an electron beam is scanned across the circuit device, secondary electrons are produced that vary in energy according to the voltage on the point that is being scanned.

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Voltage Measurement in Semiconductor Device by Electron Beam

In the circuit device that is shown schematically, a voltage is to be measured at a point PM by an electron-beam technique. When an electron beam is scanned across the circuit device, secondary electrons are produced that vary in energy according to the voltage on the point that is being scanned.

The electron beam apparatus switches the beam between the point PM and a point PR where a reference voltage is maintained. Components of the system that are not shown respond to the two values of secondary electrons and calculate the voltage at the voltage measuring point PM.

The voltages of points PM and PR generally differ, and a preliminary calibration operation is performed to establish the relationship between the signal that is derived from the electron beam and the voltage at the corresponding point on the circuit device. Ordinarily this operation is performed by switching the beam between a point where the reference voltage is maintained and a point where a range of calibration voltages is provided. In the system of the drawing, this operation is performed by holding the beam on a single point, PR, and switching the voltage at this point between the reference voltage and the calibration voltage.

A switch connects the signal Reference Frequency selectively to the electron- team apparatus for normal operation or to a terminal. Calibrate, for calibration. A chopper (represented schematically by a double-po...