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Background Statement for SEMI Draft Document 5657B
Revision to SEMI C66-0308 with title change to:GUIDE FOR TRIMETHYLALUMINUM (TMAl), 99.5% QUALITY
Notice: This background statement is not part of the balloted item. It is provided solely to assist the recipient in reaching an informed decision based on the rationale of the activity that preceded the creation of this Document.
Notice: Recipients of this Document are invited to submit, with their comments, notification of any relevant patented technology or copyrighted items of which they are aware and to provide supporting documentation. In this context, “patented technology” is defined as technology for which a patent has issued or has been applied for. In the latter case, only publicly available information on the contents of the patent application is to be provided.
Background
SEMI C66 is due for five-year review. This process is required by the Regulations Governing SEMI Standards Committees to ensure that the standard(s) are still valid.
At first, the document was balloted with no technical change, only some formatting changes. Document was rejected on the basis that it does not fit anymore the needs from the industry. The 2nd ballot, 5657A, includes some technical changes in addition to the formatting changes aiming at making the document aligned with current industry requirements. This 3rd ballot makes additional changes based on feedback received during balloting of the 2nd ballot, 5657A, which failed TC Chapter adjudication in October 2015.
Notice: Additions are indicated by underline and deletions are indicated by strikethrough.
Ballot Adjudication Information
Task Force Review / Committee AdjudicationGroup: / Task Force Review / Committee Adjudication
Date: / Precursors Task Force / Joint EU Gases & Liquid Chemicals TC Chapters meeting
Time & Timezone: / October 25, 2016 / October 26, 2016
Location: / 14:00 – 17:00, CET / 10:00 – 13:00, CET
City, Country: / Alpexpo Conference Center / Alpexpo Conference Center
Leader(s): / Jean-Marie Collard (Solvay)
/ Jean-Marie Collard (Solvay)
Standards Staff: / James Amano, / James Amano,
This meeting’s details are subject to change, and additional review sessions may be scheduled if necessary. Contact the task force leaders or Standards staff for confirmation.
Telephone and web information will be distributed to interested parties as the meeting date approaches. If you will not be able to attend these meetings in person, but would like to participate by telephone/web, please contact Standards staff.
Check on calendar of events for the latest meeting schedule.
SEMI Draft Document 5657B
Revision to SEMI C66-0308 with title change to: GUIDE FOR TRIMETHYLALUMINUM (TMAl), 99.5% QUALITY
Notice: Additions are indicated by underline and deletions are indicated by strikethrough.
1 Purpose
1.1 The purpose of this document is to provide a guideguidelines for trimethylaluminium used in the semiconductor industry.
2 Scope
2.1 The scope of this document covers a Tierof high purity trimethylaluminium,which is used in the semiconductor industry for the deposition of aluminium metal by vapour deposition techniques and aluminium oxide based layers by atomic layer deposition.
NOTICE:SEMI Standards and Safety Guidelines doThis standard does not purport to address all safety issues, if any, associated with theirits use. It is the responsibility of the users of the Documentsthis standard to establish appropriate safety and health practices, and determine the applicability of regulatory or other limitations prior to use.
3 Limitations
3.1 None
3 4 Referenced Standards and Documents
3.1 4.1 SEMIStandard
SEMI C1 Guide for the Analysis of Liquid Chemicals
3.2 4.2 ASTMStandard[1]
ASTM D5127 — Standard Guide for Ultra Pure Water Used in the Electronics and Semiconductor Industry
NOTICE: Unless otherwise indicated, all documents cited shall be the latest published versions.
4 5 Terminology
4.1 5.1 Abbreviations and Acronyms
Acronym
5.1.1 TMAl— Trimethylaluminium
4.1.1 5.1.2 PFA – Perfluoroalkoxy alkane polymer
5 6 Physical Properties (for information only)
Table 1: Properties of Trimethylaluminum
Molecular Formula / Al(CH3)3CAS Number / 75-24-1
Molecular weight (g/mol) / 72.09
Boiling point (°C) point at 760 mm Hg760mmHg / (261°F) 127°C
Vapour pressure
(P=mmHg, T=K) / log10P = 8.22-2134/T
Freezing point (°C) / (60°F) 155°C
Liquid density at 20°C (g/ml) / 0.752g/ml
Solubility in water / Reacts violently
Appearance / Pyrophoric colourless liquid
7 Suggested Values
Requirements
5.1 7.1 The suggested valuesrequirements for trimethylaluminium for Tier A are listed in Table 21.
6 8 Grade 1 Procedures
8.1 This section does not apply to this chemical.
9 Grade 2 Procedures
9.1 This section does not apply to this chemical.
10 Grade 3 Procedures
6.1 10.1 This section does not apply to this chemical.
Grade 2 Procedures
This section does not apply to this chemical.
Grade 3 Procedures
This section does not apply to this chemical.
7 11 Grade 4 Procedures
7.1 11.1 This section does not apply to this chemical.
8 12 Tier A Procedures
8.1 12.1 NOTE 1: Standardized test methods are being developed for all parameters at the purity level indicated. Until standardized test methods are published, test methodology shall be determined by user and producer. The Global Liquid Chemicals Committee considers a method to be valid only if method validation according to SEMI C1 has been demonstrated.
8.2 12.2 Trace Metals Analysis The following method has given can be used satisfactory results in determining trace metal impurities at the specified value for the elements listed in Table 21. Alternate methods may be used as long as validation according to SEMI C1 is demonstrated.
8.2.1 12.2.1 Special Reagents All water used in the trace metals analysisshould be de-ionizeddeionized water meeting the criteria for Type E1.1 in ASTM D5127.
8.2.2 12.2.2 Mixed Acid 1% HF –- 2% HNO3 prepared by dilution of ultra pure acids with appropriate weights of de-ionizeddeionized water.
8.2.3 12.2.3 Standards Composite standard solutions containing 0, 1, 2, and 4 ppb multi-element standards are prepared by diluting with mixed acid of appropriate weights for ICP-MS. Single-element standard (Si) is prepared for ICP-OES.
8.2.4 12.2.4 Sample Preparation In a clean environment, place 10 g of sample in a clean PFA Teflon closed bottle equipped with an inlet and outlet tube and evaporate under a nitrogen purge at 25C. When dry, close the inlet and the outlet tube and digest the residue at 100C for 30 minutes with 5 mL of mixed acid solution. Cool and transfer the contents with de-ionizeddeionized water. Dilute the transferred contents with de-ionizeddeionized water to a final volume of 25 mL25mL.
8.2.5 12.2.5 Analysis Analyze the samples by inductively coupled plasma optical emission spectrometry (ICP-OES) for silicon (Si) and phosphorous (P). The sample can also be analysed for pPhosphorus can also be analysed for by high resolution inductively coupled plasma mass spectrometry. Analyze the sample for all other metallic elements by inductively coupled plasma mass spectrometry (ICP-MS).
8.3 12.3 Oxygen Analysis The following method can be used has given satisfactory results in determining oxygen level at the specified value using 1H FTNMR. Note oxygen is not present in gaseous form as it reacts with TMAl forming dimethylaluminium monomethoxide. The oxygen concentration isdetermined from the alkoxide (OMe) peak which is referenced to a suitable internal reference standard.
8.3.1 12.3.1 Sample PreparationUnder an inert atmosphere transfer 0.2ml of TMAl into an NMRtube. Add 1ml of a solution of the internal standard in deuterated benzene.
8.3.2 12.3.2 Analysis Calculate oxygen from the integration of the alkoxide peak with reference to that of the internal standard.
8.4 12.4 Hydrocarbons Analysis The following method can be used has given satisfactory results in determining total hydrocarbons at the specified value using 1H FTNMR.
8.4.1 12.4.1 Sample Preparation The sample as prepared under ¶ 1211.3.1 above may be used.
8.4.2 12.4.2 Analysis Calculate hydrocarbons from the integrations of peaks in the hydrocarbon region with that of the internal standard. For convenience hydrocarbons may be calculated as hexane.
8.4.3 12.4.3 Assayby NMR Ratio of the singlet from TMAl methyl proton to total integration of all peaks in the range −-0.5 to 8ppm.
9 13 Tier B Procedures
9.1 13.1 This section does not apply to this chemical.
10 14 Tier C Procedures
10.1 14.1 This section does not apply to this chemical.
11 15 Tier D Procedures
11.1 15.1 This section does not apply to this chemical.
Table 1: Impurity Limits and Other Requirements for Trimethylaluminium
Table 2: Suggested Values for TrimethylaluminumPrevious SEMI Reference # / ----CXXXXX
Tier A
(GuideGuideline)
Assay (1H NMR) / >99.5%
Hydrocarbons (1H NMR) / 5.0ppm#1
Oxygen (O) (1H NMR) / 10ppm#1
Phosphorous (P)(ICP-OES
or Hi Res ICP-MS) / 1000 500ppb
Silicon (Si) (ICP-OES) / 1.0ppm#1
Arsenic (As) / 500 100ppb
Antimony (Sb) / --
Barium (Ba) / 100 50ppb
Boron (B) / 400 100ppb
Cadmium (Cd) / --
Calcium (Ca) / 100 50ppb
Chromium (Cr) / 100 50ppb
Cobalt (Co) / -- 50ppb
Copper (Cu) / 150ppb
Iron (Fe) / 100 80ppb
Lead (Pb) / 1000 50ppb
Lithium (Li) / -- 50ppb
Magnesium (Mg) / 50ppb
Manganese (Mn) / 50ppb
Nickel (Ni) / 400 50ppb
Potassium (K) / 1000 50 ppb
Sodium (Na) / 500 40ppb
Strontium (Sr) / -- 50ppb
Tin (Sn) / 100 50ppb
Titanium (Ti) / 100 50ppb
Vanadium (V) / --
Zinc (Zn) / 200 100ppb
#1 These contaminants are only of concern only when TMAl is being used for aluminum metal deposition.
#1 These contaminants are only of concern when TMAl is being used for aluminium metal deposition.
NOTICE: SEMI makes no warranties or representations as to the suitability of the Standards and Safety Guidelines set forth herein for any particular application. The determination of the suitability of the Standard or Safety Guideline is solely the responsibility of the user. Users are cautioned to refer to manufacturer’s instructions, product labels, product data sheets, and other relevant literature, respecting any materials or equipment mentioned herein. Standards and Safety Guidelines are subject to change without notice.
By publication of this Standard or Safety Guideline, SEMI takes no position respecting the validity of any patent rights or copyrights asserted in connection with any items mentioned in this Standard or Safety Guideline. Users of this Standard or Safety Guideline are expressly advised that determination of any such patent rights or copyrights and the risk of infringement of such rights are entirely their own responsibility.
This is a Draft Document of the SEMI International Standards program. No material on this page is to be construed as an official or adopted Standard or Safety Guideline. Permission is granted to reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other reproduction and/or distribution without the prior written consent of SEMI is prohibited.
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