ASTM F1238-95(1999)

Standard Specification for Refractory Silicide Sputtering Targets for Microelectronic Applications

SCOPE
1.1 This specification covers sputtering targets fabricated from metallic silicides (molybdenum silicide, tantalum silicide, titanium silicide, and tungsten silicide). These targets are referred to as refractory silicide targets, and are intended for use in microelectronic applications.
1.2 The values stated in SI units are regarded as standard.

General Information

• Status: Historical
• Publication Date: 09-Dec-1999
• ICS: 31.100 - Electronic tubes
• Technical Committee: F01 - Electronics
• Drafting Committee: F01.17 - Sputter Metallization

Relations

• Replaced By: ASTM F1238-95(2003) - Standard Specification for Refractory Silicide Sputtering Targets for Microelectronic Applications
• Effective Date: 10-Dec-1999

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: F 1238 – 95 (Reapproved 1999)
Standard Specification for
Refractory Silicide Sputtering Targets for Microelectronic
Applications
This standard is issued under the fixed designation F 1238; 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.
NOTE 1—Silicon content may be calculated from the following for-
1. Scope
mula:
1.1 This specification covers sputtering targets fabricated
Ratio 3 A
from metallic silicides (molybdenum silicide, tantalum silicide,
Silicon, % 5 3 100
~Ratio 3 A! 1 B
titanium silicide, and tungsten silicide). These targets are
referred to as refractory silicide targets, and are intended for
where:
use in microelectronic applications.
A 5 atomic weight of silicon, and
2, 3, 4
1.2 The values stated in SI units are regarded as standard. B 5 atomic weight of metal, (see Table 1 ).
4.3 Impurities—Maximum impurity levels shall conform to
2. Terminology
the requirements prescribed in Table 2.
2.1 Definitions of Terms Specific to This Standard:
4.4 Low Alpha Grade—When low alpha grade targets are
2.1.1 raw material lot—powder mix lot from which a
ordered they shall contain a maximum impurity level of
number of targets is fabricated.
uranium and thorium as agreed upon by the supplier and the
2.1.2 relative density—actual target density related to theo-
purchaser. The method of analysis for these elements shall also
retical density, (see 3.1.3), stated as percent.
be agreed upon.
2.1.3 theoretical density—calculated density for given com-
NOTE 2—An alternative method for defining low alpha grade targets is
position as described in 5.3.
to specify an alpha-emission rate. Specific methodology and emission rate
shall be agreed upon by supplier and purchaser.
3. Ordering Information
4.5 When required by purchaser, supplier will provide a 25
3.1 Orders for these targets shall include the following:
g sample of material that is representative of the total produc-
3.1.1 Type and ratio (see 4.1 and 4.2),
tion process for the particular raw material lot, (see Section 8).
3.1.2 Whether low alpha grade is required, (see 4.4),
3.1.3 Minimum relative density, if other than 90 %, (see
5. Physical Properties
5.1),
5.1 Minimum relative density shall be 90 %. Other relative
3.1.4 Configuration, (see 6.1),
densities may be specified by the purchaser.
3.1.5 Whether certification is required, (see 10.1).
5.2 Actual target density shall be determined by Archimedes
4. Chemical Composition
principle or other acceptable techniques.
5.3 Theoretical density shall be calculated from the follow-
4.1 Type—Targets shall be classified by the following major
ing formula:
constituents:
4.1.1 Molybdenum silicide, (Mo/Si),
C 1 ~Ratio 2 2! 3 A
Theoretical density 5
4.1.2 Tantalum silicide, (Ta/Si),
C/D 1 ~Ratio 2 2! 3 A/E
4.1.3 Titanium silicide, (Ti/Si), and
4.1.4 Tungsten silicide, (W/Si).
4.2 Ratio—Target composition shall be stated as the atomic
Molybdenum disilicide and WSi (equilibrim tetragonal phase) densities were
ratio of silicon to metal, such as Ta/Si 2.5. Ratio tolerance shall
computed from crystal lattice parameters tabulated in “Crystal Data-Determinative
be 6 0.1. Therefore, the acceptable range for a 2.5 target would
Tables, Third Edition,” Vol 2, U. S. Department of Commerce, National Bureau of
Standards and the Joint Committee on Powder Diffraction Standards, 1973, and
be 2.4 to 2.6.
JCPDS Data File Number 11-195. Tantalum disilicide (hexagonal) and
a-TiSi (orthorhombic) data are from Einspruch, N. G. and Larrabee, G. B., VLSI
This specification is under the jurisdiction of ASTM Committee F-01 on Electronics Microstructure Science, Vol 6, Table A.1, Academic Press, NY, NY,
Electronics and is the direct responsibility of Subcommittee F01.17 on Sputter 1983.
Metallization. Binary Alloy Phase Diagrams, Vol 2, ASM, Metals Park, OH.
Current edition approved Sept. 15, 1995. Published November 1995. Originally Einspruch, N. G., and Larrabee, G. B., VLSI Electronics Microstructure
e1
published as F 1238 – 89. Last previous edition F 1238 – 89 (1994) . Science, Vol 6, Table A.1, Academic Press, NY, NY, 1983.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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