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Integrated Circuit Inspection

IP.com Disclosure Number: IPCOM000089933D
Original Publication Date: 1968-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Kresge, JD: AUTHOR [+3]

Abstract

Quality inspection of miniature integrated circuit chips or wafers with a scanning electron microscope is adaptable to an automated process. Circuit wafer 1 is placed within the vacuum chamber of scanning electron microscope 2 and scanned with electron beam 3. As beam 3 traverses the conductors, junctions and substrate of the wafer, varying current is induced with each scan which is detected across leads 4. Only two connections are required by leads 4, across either two voltage planes or the ground plane and one voltage plane. The beam-induced current, after amplification at 5, is directed to comparing unit 6.

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Integrated Circuit Inspection

Quality inspection of miniature integrated circuit chips or wafers with a scanning electron microscope is adaptable to an automated process. Circuit wafer 1 is placed within the vacuum chamber of scanning electron microscope 2 and scanned with electron beam 3. As beam 3 traverses the conductors, junctions and substrate of the wafer, varying current is induced with each scan which is detected across leads 4. Only two connections are required by leads 4, across either two voltage planes or the ground plane and one voltage plane. The beam-induced current, after amplification at 5, is directed to comparing unit 6.

The induced current value is digitized and compared with previously stored values resulting from beam scans of an acceptable wafer and retained in storage unit 7. Computer 8 controls the scan generator and synchronizes the comparison of current values for corresponding scans. Wafers having defects in metalization, junctions, alignment or electrical characteristics can be detected for rejection or rework.

The inspection system can be arranged for inspecting wafers, bearing redundant elements, and programming the computer to direct subsequent interconnections between acceptable components.

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