ASTM F1723-96

Standard Practice for Evaluation of Polycrystalline Silicon Rods by Float-Zone Crystal Growth and Spectroscopy

SCOPE
1.1 This practice recommends procedures for sampling polycrystalline silicon rods and growing single crystals from these samples by the float-zone technique. The resultant single crystal ingots are analyzed by spectrophotometric methods to determine the trace impurities in polysilicon. These trace impurities are acceptor (usually boron or aluminum, or both), donor (usually phosphorus or arsenic, or both), and carbon impurities.
1.2 The useful range of impurity concentration covered by this practice is 0.002 to 100 parts/billion atomic (ppba) for acceptor and donor impurities, and 0.05 to 5 parts/million atomic (ppma) for carbon impurity. These impurities are analyzed in the ingot samples by infrared or photoluminescence spectroscopy.
1.3 This practice is applicable only to evaluation of polysilicon ingots grown by a method that utilizes a slim silicon rod (filament) upon which polycrystalline silicon is deposited.
1.4 This practice uses hot acid to etch away the surface of the polysilicon rod. The etchant is potentially harmful and must be handled in an acid exhaust fume hood with utmost care at all times. Hydrofluoric acid solutions particularly are hazardous and should not be used by anyone who is not familiar with the specific preventative measures and first aid treatments given in the appropriate Material Safety Data Sheet.
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: 71.040.50 - Physicochemical methods of analysis
• Technical Committee: F01 - Electronics

Relations

• Replaced By: ASTM F1723-02 - Standard Practice for Evaluation of Polycrystalline Silicon Rods by Float-Zone Crystal Growth and Spectroscopy (Withdrawn 2003)
• 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NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn.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 1723 – 96
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 Practice for
Evaluation of Polycrystalline Silicon Rods by Float-Zone
1
Crystal Growth and Spectroscopy
This standard is issued under the fixed designation F 1723; 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.
INTRODUCTION
This practice replaces Method F 574, and Practice F 41. Method F 574 and Practice F 41 are
obsolete, describing multi-pass zoning and vacuum zoning practices, and resistivity measurements for
the calculation of impurity concentrations. One pass zoning and analysis by spectrophotometric
techniques to identify and quantify the acceptor and donor elements have replaced the obsolete
methods. Expanded sampling plans, the use of reference specimens, and practices for sampling of
ingots are improvements made to these standards.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This practice recommends procedures for sampling
2
polycrystalline silicon rods and growing single crystals from D 5127 Guide for Electronic Grade Water
F 26 Test Methods for Determining the Orientation of a
these samples by the float-zone technique. The resultant single
3
crystal ingots are analyzed by spectrophotometric methods to Semiconductive Single Crystal
F 47 Test Method for Crystallographic Perfection of Silicon
determine the trace impurities in polysilicon. These trace
3
impurities are acceptor (usually boron or aluminum, or both), by Preferential Etch Techniques
F 397 Test Method for Resistivity of Silicon Bars Using a
donor (usually phosphorus or arsenic, or both), and carbon
3
impurities. Two-Point Probe
F 723 Practice for Conversion Between Resistivity and
1.2 The useful range of impurity concentration covered by
Dopant Density for Boron-Doped and Phosphorus-Doped
this practice is 0.002 to 100 parts/billion atomic (ppba) for
3
Silicon
acceptor and donor impurities, and 0.05 to 5 parts/million
3
F 1241 Terminology of Silicon Technology
atomic (ppma) for carbon impurity. These impurities are
F 1389 Test Method for Photoluminescence Analysis of
analyzed in the ingot samples by infrared or photolumines-
3
Single Crystal Silicon for III-V Impurities
cence spectroscopy.
F 1391 Test Method for Substitutional Carbon Content of
1.3 This practice is applicable only to evaluation of poly-
3
Silicon by Infrared Absorption
silicon ingots grown by a method that utilizes a slim silicon rod
F 1630 Test Method for Low Temperature FT-IR Analysis
(filament) upon which polycrystalline silicon is deposited.
3
of Single Crystal Silicon for III-V Impurities
1.4 This practice uses hot acid to etch away the surface of
2.2 Federal Standards:
the polysilicon rod. The etchant is potentially harmful and must
Federal Standard 209E Airborne Particulate Cleanliness
be handled in an acid exhaust fume hood with utmost care at all
4
Classes in Cleanrooms and Clean Zones
times. Hydrofluoric acid solutions particularly are hazardous
2.3 SEMI Standards:
and should not be used by anyone who is not familiar with the
5
C 3 Specification for Gases
specific preventative measures and first aid treatments given in
5
C 7 Specification for Reagents
the appropriate Material Safety Data Sheet.
1.5 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
3.1 Definitions: Terms used in this practice are defined in
responsibility of the user of this standard to establish appro-
Terminology F 1241 or below.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2
Annual Book of ASTM Standards, Vol 11.01.
3
Annual Book of ASTM Standards, Vol 10.05.
1 4
This practice is under the jurisdiction of ASTM Committee F-1 on Electron- Available from Superintendent of Documents, U.S. Government Printing
icsand is the direct responsibility of Subcommittee F01.06 on Silicon Materials and Office, Washington, DC 20402.
5
Process Control. Book of SEMI Standards, available from Semiconductor Equipment and
Current edition approved July 10, 1996. Published September 1996. Materials International, 805 E. Middlefield Road, Mountain View, CA 94043.
1

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F 1723
3.2 Definitions of Terms Specific to This Standard: 5.3 The concentration of acceptor and donor elements and
3.2.1 control rod, n—a cylinder of polysilicon taken from a carbon in the polysilicon is used by the crystal grower to
polysilicon rod with a unif
...