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Detection of Resistive Shorts in Active Devices

IP.com Disclosure Number: IPCOM000073820D
Original Publication Date: 1971-Feb-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

DeStafeno, J: AUTHOR [+2]

Abstract

A scanning electron beam is employed to make two probe electrical conduction continuity measurements on a completed semiconductor device. This method of testing for shorts permits determination of transistor defects buried under multilayer metallization and passivation structures while requiring only one mechanical contact.

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Detection of Resistive Shorts in Active Devices

A scanning electron beam is employed to make two probe electrical conduction continuity measurements on a completed semiconductor device. This method of testing for shorts permits determination of transistor defects buried under multilayer metallization and passivation structures while requiring only one mechanical contact.

A stationary contact is made to the device by a wire bond. In effect, a second contact is made by the scanning electron beam. The stationary contact collects beam induced current which is amplified and displayed on a cathode-ray tube raster pattern synchronized with the scanning electron beam. The conduction between regions in the specified semiconductor devices is displayed as the pattern of light and dark metallized contacts to the device regions.

When irradiated by an electron beam, an active device displays characteristic contrasting changes of the sequential junctions. If the emitter and collector of a transistor are white and the base black when neighboring diffusions are shorted, then the sequential contrast arrangement changes and neighboring junctions have the same contrast. This contrast phenomenon is used for resistive shorts determination for transistors buried under several layers of metallization- passivation structure. The contrast effect is relayed from the transistors to their metal contact strips. Transistor shorts are observed as displayed by the contrast differences on the upp...