Dynamically switched voltage screen

Electricity: measuring and testing – Fault detecting in electric circuits and of electric components – Of individual circuit component or element

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Reexamination Certificate

active

06927595

ABSTRACT:
This invention teaches an apparatus and method for determining a more efficient quality assurance or reliability test screen without falsely rejecting, i.e., over stressing, short channel length devices during voltage stress test screening. Short channel lengths devices fabricated on a semiconductor wafer have a higher tendency to fail at voltage levels that would otherwise not harm long channel length devices. The failures, however, are not related to device defects. Protection to the more vulnerable devices is provided by determining the speed of the die prior to the voltage test screen, thus, segregating the devices based on operational speed performance. Next, a lower voltage is effectively applied during wafer probe test to the faster devices, which directly correspond to the population of short channel devices. A preferred measurement for device speed entails measuring the drain-to-source current of each FET, and dividing the resultant sum by the device gate channel width. The devices with the higher values represent the faster devices. Alternatively, since faster devices draw more current, the supply current specification may be adjusted based on operational speed measurements, for fast and slow devices accordingly.

REFERENCES:
patent: 4335457 (1982-06-01), Early
patent: 4351108 (1982-09-01), Johnson
patent: 4871963 (1989-10-01), Cozzi
patent: 4902969 (1990-02-01), Gussman
patent: 5093982 (1992-03-01), Gussman
patent: 5099196 (1992-03-01), Longwell et al.
patent: 5196787 (1993-03-01), Ovens et al.
patent: 5286656 (1994-02-01), Keown et al.
patent: 5519331 (1996-05-01), Cowart et al.
patent: 5552739 (1996-09-01), Keeth et al.
patent: 5604447 (1997-02-01), Takano
patent: 5625288 (1997-04-01), Snyder et al.
patent: 6259268 (2001-07-01), Crozier et al.
patent: 6574760 (2003-06-01), Mydill
patent: 6094786 (1994-08-01), None
IBM Technical Disclosure Bulletin, “Noise Reduction Method for VLSI Logic Chips”, vol. 30, No. 3, Aug. 1987.
IBM Technical Disclosure Bulletin, “Test System for Narrowing the Range of Performance Characteristics of Monolithic Integrated Circuits”, vol. 15, No. 4, Sep. 1972.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Dynamically switched voltage screen does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Dynamically switched voltage screen, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dynamically switched voltage screen will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3451412

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.