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SEMI M8-0703 © SEMI 1984, 2003 3 6.2 If test wafers are specifi ed to be edge contour ed, the profile shall conform to the requirements in Section 5.2 of SEMI M 1 and to the dim ension C y in the associated polished sili…

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SEMI M8-0703 © SEMI 1984, 2003 2
5 Ordering Information
5.1 Small Diameter Wafers
5.1.1 Items that may be specified when ordering silicon
wafers are listed in SEMI M18. Not all of these items
are required for ordering small diameter (2 in., 3 in.,
100 mm, and 125 mm) test wafers. The following
items are included in the three specification groups
shown in Table 1; numbers in square brackets following
the item are the item numbers in SEMI M18:
5.1.1.1 Group 1, General and Geometrical — Growth
method [1.1], diameter [6.1], surface orientation [6.9],
thickness [6.7], orientation fiducials (flats and notches)
[6.2–6.5], and edge profile [6.6].
5.1.1.2 Group 2, Surface Characteristics — Surface
defects as listed in Tables 3 and 4 [7.1–7.2, 8.1–8.16].
5.1.1.3 Group 3, Basic Intrinsic Properties —
Conductivity type [1.3], dopant [1.4], and resistivity
[2.1].
Table 1 Classifications for Small Diameter Wafers
Classification Applicable Specification Groups
A 1, 2, 3
B 1, 2
C 1
5.1.2 Not all of the above items must be specified
explicitly; the specifications for many of the items are
determined by the combination of wafer classification
and nominal diameter. In all cases, the following must
be specified on the purchase order for all classes of
small diameter test wafers:
5.1.2.1 Wafer Classification (A, B or C),
5.1.2.2 Nominal diameter and surface orientation,
5.1.2.3 Growth method (see Section 7.1),
5.1.2.4 Lot acceptance procedures (see Section 9.1),
5.1.2.5 Certification (if required) (see Section 12),
5.1.2.6 Packing and Marking (see Section 13),
5.1.2.7 Any options listed in the table, and
5.1.2.8 Appropriate test methods when more than one
is listed for the parameter in Table 1 of SEMI M18.
5.1.3 For Class A and B test wafers, that require
controlled surface characteristics, certain surface defect
limits (see Section 11), must be specified in addition to
the items listed in Section 5.1.2, see Table 3, Sections
8.1–8.16.
5.1.4 For Class A wafers, the following must be
specified in addition to the items listed in Sections 5.1.2
and 5.1.3 (see Section 8.1):
5.1.4.1 Conductivity type
5.1.4.2 Resistivity
5.2 Large Diameter Wafers
5.2.1 Items that may be specified when ordering silicon
wafers are listed in SEMI M18. Not all of these items
are required for ordering large diameter (150, 200, and
300 mm) test wafers. The following items are included
in the two specification groups shown in Table 2;
numbers in square brackets following the item are the
item numbers in SEMI M18.
Table 2 Wafer Classifications for Large Diameter
Wafers
Classifications Applicable Specification Groups
Mechanical 1
Process 1, 2
5.2.1.1 Group 1, General and Geometrical ― Growth
method [1.1], diameter [6.1], surface orientation [6.9],
thickness [6.7], orientation fiducials (flats and notches)
[6.2–6.5], and edge profile [6.6].
5.2.1.2 Group 2, Surface and Intrinsic Properties ―
Surface defects as listed in Table 3 [7.1–7.2, 8.1–8.16],
conductivity type [1.3], dopant [1.4], and resistivity
[2.1].
5.2.2 Not all the specifications must be specified
explicitly; the specifications for many of the items are
determined by wafer classification and nominal
diameter. In all cases the following must be specified
on the purchase order for all classes of large diameter
test wafers:
5.2.2.1 Wafer Classification (Mechanical or Process),
5.2.2.2 Nominal diameter and surface orientation,
5.2.2.3 Growth method (see Section 7.1),
5.2.2.4 Lot acceptance procedures (see Section 9.1),
5.2.2.5 Certification (if required) (see Section 12),
5.2.2.6 Packing and Marking (see Section 13),
5.2.2.7 Any options listed in the table, and
5.2.2.8 Appropriate test methods when more than one
is listed for the parameter in Table 1 of SEMI M18.
6 Dimensions and Permissible Variations
6.1 The material shall conform to the parameters as
specified in Table 3, 4, or 5.
SEMI M8-0703 © SEMI 1984, 2003 3
6.2 If test wafers are specified to be edge contoured,
the profile shall conform to the requirements in Section
5.2 of SEMI M1 and to the dimension C
y
in the
associated polished silicon wafer standard applicable to
the same nominal diameter and thickness. If edge
profiling is not specified explicitly, there is no
specification for the geometrical dimensions of any
profiles that may exist on the wafers.
6.3 The material shall conform to the crystallographic
orientation details as listed in the tables.
7 Materials and Manufacture
7.1 The material shall consist of wafers from crystals
grown by the process specified in the purchase order or
contract.
8 Electrical Requirements
8.1 Class A test wafers and process test wafers (only)
shall conform to the details specified in the purchase
order or contract, as follows:
8.1.1 Conductivity type
8.1.2 Resistivity
9 Sampling
9.1 Unless otherwise specified, ASTM Practice E 122
shall be used. When so specified, appropriate sample
sizes shall be selected from each lot in accordance with
ANSI/ASQC Z1.4. Each quality characteristic shall be
assigned an acceptable quality level (AQL) and lot total
percent defective (LTPD) value in accordance with
ANSI/ASQC Z1.4 definitions for critical, major, and
minor classifications. If desired and so specified in the
contract or order, each of these classifications may
alternatively be assigned cumulative AQL and LTPD
values. Inspection levels shall be agreed upon between
the supplier and the purchaser.
10 Test Methods
NOTE 1: Silicon wafers are extremely fragile. While the
mechanical dimensions of a wafer can be measured by use of
tools such as micrometer calipers and other conventional
techniques, the wafer may be damaged physically in ways that
are not immediately evident. Special care must therefore be
used in the selection and execution of measurement methods.
NOTE 2: The crystal growth method (for example,
Czochralski or Float Zone) and dopant (for example, boron,
phosphorous or antimony) used are difficult to ascertain in
finished wafers. Verification test procedures for certification
of these characteristics shall be agreed upon between the
supplier and the purchaser.
10.1 Use test methods for the specified quantities as
listed in Table 1 of SEMI M18.
11 Surface Defect Criteria
11.1 Minimal Conditions or Dimensions — The
minimal conditions or dimensions for defects stated
below shall be used for determining wafer acceptability.
Anomalies smaller than these limits shall not be
considered defects.
11.2 area contamination — any foreign matter on the
surface in localized areas which is revealed under the
inspection lighting conditions as discolored, mottled, or
cloudy appearance resulting from smudges, stains,
water spots, etc.
11.3 crack — any anomaly conforming to the
definition and greater than 0.25 mm (0.010 inch) in
total length.
11.4 crow's foot — any anomaly conforming to the
definition and greater than 0.25 mm (0.010 inch) in
total length.
11.5 dimple — any smooth surface depression greater
than 3 mm in diameter.
11.6 edge chip and indent — any edge anomaly
including saw exit marks conforming to the definition
and greater than 0.25 mm (0.010 inch) in radial depth
and peripheral length.
11.7 hand scribe mark — any mark such as that caused
by a diamond scribe that is visible under diffuse
illumination.
11.8 haze — haze is indicated when the image of a
narrow beam tungsten lamp filament is detectable on
the polished wafer surface. (Under some conditions
contamination may appear as haze.)
11.9 orange peel — any roughened surface conforming
to the definition that is observable under diffuse
illumination.
11.10 particulate contamination — distinct particles
resting on the surface, which is revealed under,
collimated light as bright points.
11.11 pit — any individually distinguishable non-
removable surface anomaly conforming to the
definition and visible when viewed under high intensity
illumination.
11.12 saw marks — any surface irregularities
conforming to the definition that is observable under
diffuse illumination.
11.13 scratch — any anomaly conforming to the
definition and having a length-to-width ratio greater
than 5:1.
11.14 slip — any pattern of short ridges aligned along
<110> directions and visible under diffuse illumination.
SEMI M8-0703 © SEMI 1984, 2003 4
11.15 striations — any helical features conforming to
the definition and visible under diffuse illumination.
12 Certification
12.1 Upon request of the purchaser in the contract or
order, a manufacturer’s or supplier’s certification that
the material was manufactured and tested in accordance
with this specification, together with a report of the test
results, shall be furnished at the time of shipment.
12.2 In the interest of controlling inspection costs, the
supplier and the purchaser may agree that the material
shall be certified as “capable of meeting” certain
requirements. In this context, “capable of meeting”
shall signify that the supplier is not required to perform
the appropriate tests in Section 9. However, if the
purchaser performs the test and the material fails to
meet the requirement, the material may be subject to
rejection.
13 Packing and Marking
13.1 Special packing requirements shall be subject to
agreement between the supplier and the purchaser.
Otherwise, all wafers shall be handled, inspected, and
packed in such a manner as to avoid chipping,
scratches, and contamination, and in accordance with
the best industry practices, to provide ample protection
against damage during shipment.
13.2 The wafers supplied under this specification shall
be identified by appropriately labeling the outside of
each box or other container and each subdivision
thereof in which it may reasonably be expected that the
wafers will be stored prior to further processing.
Table 3 Specifications for Small Diameter Silicon Test Wafers
Item Specification
CLASSIFICATION
A B C
1.0
General Characteristics
1.1 Growth Method User specified
1.2 Crystal Orientation User specified
1.2.1 Crystal Orientation User specified
1.3 Conductivity Type User specified
1.4 Dopant User specified
1.5 Nominal Edge Exclusion Distance for
FQA
Not specified
2.0
Electrical Characteristics
2.1 Resistivity User specified
2.2 Radial Resistivity Variation (RRG) Optional
2.3 Resistivity Striations Unspecified
2.4 Minority Carrier Lifetime Unspecified
3.0
Chemical Characteristics
3.1 Oxygen Concentration Unspecified
3.2 Radial Oxygen Variation Unspecified
3.3 Carbon Concentration Unspecified
4.0
Structural Characteristics
4.1 Dislocation Etch Pit Density None Optional Unspecified
4.2 Slip None Optional Unspecified
4.3 Lineage None Optional Unspecified
4.4 Twins None Optional Unspecified
4.5 Swirl None Optional Unspecified
4.6 Shallow Pits None Optional Unspecified
4.7 OISF Optional Optional Unspecified
4.8 Oxide Precipitates Unspecified