ASTM F1259M-96(2003)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: F1259M – 96 (Reapproved 2003)
Standard Guide for
Design of Flat, Straight-Line Test Structures for Detecting
Metallization Open-Circuit or Resistance-Increase Failure
Due to Electromigration (Metric)
This standard is issued under the fixed designation F1259M; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.2 test structure—a passive metallization structure, with
terminals to permit electrical access that is fabricated on a
1.1 This guide covers recommended design features for test
semiconductor wafer by the normal procedures used to manu-
structures used in accelerated stress tests, as described in Test
facture microelectronic integrated devices.
Method F1260M, to characterize the failure distribution of
3.1.3 metallization—the thin-film metallic conductor that
interconnect metallizations that fail due to electromigration.
serves as the primary conductor path in electrical interconnects
1.2 This guide is restricted to structures with a straight test
of microelectronic integrated circuits.
line on a flat surface that are used to detect failures due to an
open-circuit or a percent-increase in resistance of the test line.
4. Significance and Use
1.3 This guide is not intended for testing metal lines whose
4.1 This guide is intended for the design of test structures
widths are approximately equal to or less than the estimated
used in measuring the median-time-to-failure and sigma (see
mean size of the metal grains in the metallization line.
Test Method F1260M) of metallizations fabricated in ways that
1.4 This guide is not intended for test structures used to
are of interest to the parties to the test.
detect random defects in a metallization line.
4.2 This guide is intended to provide design features that
1.5 Metallizations tested and characterized are those that are
facilitate accurate test-line resistance measurements used in
used in microelectronic circuits and devices.
estimating metallization temperature. The design features are
2. Referenced Documents also intended to promote temperature uniformity along the test
line and a minimum temperature gradient at the ends of the test
2.1 ASTM Standards:
line when significant joule heating is produced during the
F1260M Test Method for Estimating Electromigration Me-
accelerated stress test.
dian Time-To-Failure and Sigma of Integrated Circuit
Metallizations (Metric)
5. Design Features
F1261M Test Method for Determining the Average Electri-
3 5.1 The test structure shall have at least four terminals: two
cal Width of a Straight, Thin-Film Metal Line (Metric)
to conduct current and two to measure the voltage. The basic
3. Terminology features are illustrated in Fig. 1.
5.1.1 The metallization to be characterized by the test
3.1 Definitions of Terms Specific to This Standard:
structure shall be in the form of a straight test line of width w,
3.1.1 test chip—an area on a semiconductor wafer contain-
where w shall be larger than the estimated mean size of the
ing one or more test structures having a specified or implied
metal grains in the metallization of the test line.
purpose.
NOTE 1—The median-time-to-failure, t , (see Test Method F1260M)
will be a monotonically increasing function of line width w, when w is
This guide is under the jurisdiction of ASTM Committee F01 on Electronics larger than the mean size of the metal grains in the test line.
and is the direct responsibility of Subcommittee F01.11 on Nuclear and Space
NOTE 2—If the mean size of the metal grains in the test line is larger
Radiation Effects.
than the line width, there is an increasing probability, for decreasing line
Current edition approved June 10, 2003. Published June 2003. Originally
width, that failure will occur in the wider end segment of the structure,
approved in 1989. Last previous edition approved in 1996 as F1259M – 96. DOI:
rather in the test line, for decreasing line width. This is because both t
10.1520/F1259M-96R03.
and sigma increase with decreasing line width in this regime.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
5.1.2 The length of the test line shall be 800 µm. Adjacent-
Standards volume information, refer to the standard’s Document Summary page on
running lines may be included in the desi
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