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Method for a Power Test Screen of a Semiconductor Device Tested at Two Temperatures

IP.com Disclosure Number: IPCOM000176322D
Original Publication Date: 2008-Nov-12
Included in the Prior Art Database: 2008-Nov-12
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Abstract

This invention is a method for setting a power measurement screen for semiconductor devices tested at two different test temperatures using IDDQ measurements, with a delta IDDQ measurement used at the lower test temperature.

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Method for a Power Test Screen of a Semiconductor Device Tested at Two

Temperatures

The invention is a method that allows for an improved correlation for setting quiescent current

(IDDQ)

power screen limits between a test taken at two temperatures(semiconductor wafer and

module) by using an optimized dual voltage difference when taking the IDDQ reading at the

lower temperature. This improved correlation is due to reducing leakage in the semiconductor

caused by device variation in gate oxide thickness. This allows for the device variation to be

accounted for insitu instead of having to provide these data to the tester separately. By

improving the correlation between the two IDDQ tests, a yield improvement is seen at both tests

resulting in cost savings by:
1.

Not failing wafer die that would pass at module test(loss die cost)

Not building wafer die that fail at module test(loss module package costs)

This invention uses IDDQ testing for power screening where as previous publications use IDDQ

testing for defect detection only.

Description of Method
Method for setting a power screen limit for testing a semiconductor device at two temperatures

by using quiescent current (IDDQ) and a dual voltage delta comprising the steps of: measuring a first quiescent current at a first voltage at a first lower temperature; (wafer below) measuring a second quiescen...