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Contactless Resistance Measurement by a Combination of E-Beam and Photoemission Methods

IP.com Disclosure Number: IPCOM000038338D
Original Publication Date: 1987-Jan-01
Included in the Prior Art Database: 2005-Jan-31
Document File: 2 page(s) / 14K

Publishing Venue

IBM

Related People

Beha, JG: AUTHOR [+5]

Abstract

This article is concerned with the contactless measuring of line resistances in circuit packaging, combining E-beam technology and laser-excited photoemission. At present there is a large and steadily growing interest in contactless resistance measurements. One topic in which this is an important problem is the conduction-line testing in packaging technology. Up to now only the measurement of opens and shorts was possible by using contactless E-beam measurement methods. Presently there is no solution for contactless resistance measurements on highly integrated structures. The only approach which currently exists is the measurement of RC-time constants by an E-beam method from which the resistance can be calculated if the capacities of the system are known.

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Contactless Resistance Measurement by a Combination of E-Beam and Photoemission Methods

This article is concerned with the contactless measuring of line resistances in circuit packaging, combining E-beam technology and laser-excited photoemission. At present there is a large and steadily growing interest in contactless resistance measurements. One topic in which this is an important problem is the conduction-line testing in packaging technology. Up to now only the measurement of opens and shorts was possible by using contactless E-beam measurement methods. Presently there is no solution for contactless resistance measurements on highly integrated structures. The only approach which currently exists is the measurement of RC-time constants by an E-beam method from which the resistance can be calculated if the capacities of the system are known. This request for additional knowledge about the capacities is a serious drawback in this approach. From the known order of magnitude of the capacities, this E-beam method is able to determine minimum detectable resistances between 5 and 10 ML. The line resistance measurement method proposed here uses a combination of E-beam and photoemission methods. The key features of this method are that it is independent of the line capacitance and that the structures used for the determination of the voltage between the two ends of the conduction line are clearly separated in energy, therefore allowing voltage measurement with high accuracy. The independence from capacities is reached by using a steady- state approach with a continuous current flowing in the conducting line. To achieve a continuous current in the line to be tested, electrons are injected at one end of the conducting line by an E-beam and the electrons are extracted from the other end of the line by photoemission. The combination of E-beam (injection of electrons, i.e., the number of secondary electrons is smaller than the number of incident electrons) and photoemission allows a clear energy separation of the electron distributions emitted from the two ends of the conducting line. Because of the energy separation, the potential of a high voltage resolution of a few millivolts is given, which is a precondition to be...