ASTM F534-97

Standard Test Method for Bow of Silicon Wafers

SCOPE
1.1 This test method covers determination of the average amount of bow of nominally circular silicon wafers, polished or unpolished, in the free (non-clamped) condition.  
1.2 This test method is intended primarily for use with wafers that meet the dimension and tolerance requirements of SEMI Specifications M1.
1.3 This test method can also be applied to circular wafers of other semiconducting materials, such as gallium arsenide, or electronic substrate materials, such as sapphire or gadolinium gallium garnet, that have a diameter of 25 mm or greater, a thickness of 0.18 mm or greater, and a ratio of diameter to thickness up to 250. Wafers to be tested may have one or more fiducial flats provided they are located in such a way that the slice can be centered on the support pedestals (see 7.1.2) without falling off.  
1.4 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.
1.5  This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Jan-2002
• ICS: 29.045 - Semiconducting materials
• Technical Committee: F01 - Electronics

Relations

• Replaced By: ASTM F534-02 - Standard Test Method for Bow of Silicon Wafers
• Effective Date: 10-Jan-2002

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn. Contact ASTM International (www.astm.org) for the latest information.
Designation: F 534 – 97
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
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Bow of Silicon Wafers
This standard is issued under the fixed designation F 534; 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 (e) indicates an editorial change since the last revision or reapproval.
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1. Scope and Work Station Requirements
1.1 This test method covers determination of the average
3. Terminology
amount of bow of nominally circular silicon wafers, polished
3.1 Definitions:
or unpolished, in the free (non-clamped) condition.
3.1.1 back surface—of a semiconductor wafer, the exposed
1.2 This test method is intended primarily for use with
surface opposite to that upon which active semiconductor
wafers that meet the dimension and tolerance requirements of
devices have been or will be fabricated.
SEMI Specifications M1.
3.1.2 bow—of a semiconductor wafer, the deviation of the
1.3 This test method can also be applied to circular wafers
center point of the median surface of a free, unclamped wafer
of other semiconducting materials, such as gallium arsenide, or
from a median-surface reference plane established by three
electronic substrate materials, such as sapphire or gadolinium
points equally spaced on a circle with diameter a specified
gallium garnet, that have a diameter of 25 mm or greater, a
amount less than the nominal diameter of the wafer.
thickness of 0.18 mm or greater, and a ratio of diameter to
3.1.2.1 Discussion—If the median surface of a free,
thickness up to 250. Wafers to be tested may have one or more
unclamped wafer has a curvature that is everythere the same,
fiducial flats provided they are located in such a way that the
bow is a measure of its concave or convex deformation,
slice can be centered on the support pedestals (see 7.1.2)
independent of any thickness variation that may be present.
without falling off.
Positive values of bow denote a convex (mounded) median
1.4 The values stated in inch-pound units are to be regarded
surface when the wafer is positioned with its front surface up.
as the standard. The values given in parentheses are for
Conversely, negative values of bow denote a concave (dished)
information only.
median surface when the wafer is positioned with its front
1.5 This standard does not purport to address the safety
surface up. Although bow may be caused by unequal stresses
concerns, if any, associated with its use. It is the responsibility
on the two exposed surfaces of the wafer, it cannot be
of the user of this standard to establish appropriate safety and
determined from measurements on a single exposed surface.
health practices and determine the applicability of regulatory
3.1.3 front surface—of a semiconductor wafer, the exposed
limitations prior to use.
surface upon which active semiconductor devices have been or
will be fabricated.
2. Referenced Documents
3.1.4 median surface—of a semiconductor wafer, the locus
2.1 ASTM Standards:
of points in the wafer equidistant between the front and back
F 533 Test Method for Thickness and Thickness Variation
surfaces.
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of Silicon Slices
F 657 Test Method for Measuring Warp and Total Thickness
4. Summary of Test Method
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Variation on Silicon Wafers by Noncontact Scanning
4.1 The wafer is supported, front surface upward, on three
2.2 SEMI Standard:
points equally spaced on the circumference of a circle whose
M1 Specifications for Polished Monocrystalline Silicon
diameter is slightly smaller than the wafer diameter. The
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Slices
distance between the center point of the front surface and the
2.3 Federal Standard:
reference plane formed by the three supporting points is
Fed. Std. No. 209B Controlled Environment Clean Room
measured with a lightly loaded indicator. The wafer is turned
over and the measurement is repeated with the wafer supported
at three points directly opposite (through the thickness of the
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wafer) from the original three points. An average value of the
This test method is under the jurisdiction of ASTM Committee F-1 on
Electronics and is the direct responsibility of Subcommittee F01.06 on Silicon bow of the wafer is calculated from these two measurements.
Materials and Process Control.
Current edition approved June 10, 1997. Published August 1997. Originally
published as F534 – 77 T. Last previous edition F534 – 91.
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Annual Book of ASTM Standards, Vol 10.05. Available from GSA Business Service Centers in Boston, New York, Atlanta,
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Available from Semiconductor Equipment and Materials International, 805 E. Chicago, Kansas City, MO, Fort Worth, Denver, Seattl
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