FTIR Detection of Outgassing Chemicals: Instantaneous and Comprehensive Identification and Quantitation

Transcription

1 FTIR Detection of Outgassing Chemicals: Instantaneous and Comprehensive Identification and Quantitation John C. Hulteen, Ph.D. Environmental Specialist 3M St. Paul, MN DISKCON 2000 San Jose, CA September 19, 2000

2 Airborne Molecular Contaminants (AMC) Sources: plastics, tapes, adhesives, pumps, process chemicals, solvents, people, etc. Effects: corrosion, hazing, molecular contamination, adhesion, etc. Major Issue : How do you quantitate and speciate molecular compounds that are outgassed from disk drive materials in a timely manner.

3 An Innovative New Alternative to Existing Technologies. Detection of acids, bases, volatiles and semi-volatiles simultaneously. Quantitation and identification of compounds. Fast collection and analysis time - manufacturing requirement. Low detection limits as required by the microelectronics industry. Rugged method and instrumentation for plant application. Simple equipment maintenance and operation.

4 3M Proprietary FTIR Static Headspace (SHS) temperature controller infrared source and detector heated 4.5 L chamber sample drawer

5 FTIR Static Headspace (SHS): Outgassing Profile FTIR Static HS Gas Cell IR Source Total Cumulative Outgassing vs Time IR Detector Absorbance Units SAMPLE FITR Spectra ng/cm 2 Time

6 FTIR Static Headspace (SHS): Outgassing Profile FTIR Static HS Gas Cell Total Cumulative Outgassing vs Time Absorbance Units SAMPLE FITR Spectra ng/cm 2 Time

7 FTIR Static Headspace (SHS): Outgassing Profile FTIR Static HS Gas Cell Total Cumulative Outgassing vs Time Absorbance Units SAMPLE FITR Spectra ng/cm 2 Time

8 FTIR Static Headspace (SHS): Outgassing Profile FTIR Static HS Gas Cell Total Cumulative Outgassing vs Time Absorbance Units SAMPLE FITR Spectra ng/cm 2 Time

9 FTIR Static Headspace (SHS): Outgassing Profile FTIR Static HS Gas Cell Total Cumulative Outgassing vs Time Absorbance Units SAMPLE FITR Spectra ng/cm 2 Time

10 Determination of Extent of Outgassing in SHS FTIR 9 8 ppm v of acrylate in cell TOTAL OUTGASSING OF THE SATURATED ACRYLATE HEADSPACE WAS REACHED AT THIS TEMPERATURE OR Purge with N 2 TOTAL OUTGASSING Time (min) Stop N 2 purge and reseal cell Label Tape at 85 C

11 The Basic Principle of Infrared Spectroscopy Formic Acid O C 1775 cm -1 H O H O 638 cm -1 C H O H 1105 cm-1 C H O H O Absorbance 2945 cm -1 H O C O H Energy (wavenumbers cm -1 ) Fingerprint Region

12 FTIR Detection of Acids Collection Time < 2 minutes hydrofluoric acid (HF) 3 ppm v Absorbance acrylic acid 16 ppm v hydrochloric acid (HCl) 29 ppm v acetic acid 11 ppm v Energy (wavenumbers cm -1 )

13 Example of Outgassing Acids in Tape Products Tape Sample A Formic acid detected in outgas after 2 minutes. Formic Acid Standard Fully outgassed at 570 ng/cm 2 or 41 ppm w after 120 minutes. FTIR outgassing spectra of a tape sample and standard at 85 o C Cummulative Outgassing Concentration (ng/cm2) :00 0:28 0:57 1:26 1:55 2:24 Time (hr:min)

14 Example of Outgassing Acids in Tape Products Tape Sample B Acetic acid detected in outgas after 2 minutes. Acetic Acid Standard Fully outgassed at 740 ng/cm 2 or 33 ppm w after 14 hours. FTIR outgassing spectra of a tape sample and standard at 85 o C Cummulative Outgassing Concentration (ng/cm2) :00 2:24 4:48 7:12 9:36 12:00 14:24 16:48 Time (hr:min)

15 FTIR Detection of Bases Collection Time < 2 minutes ammonia 8.5 ppm v Absorbance diethyl amine 25 ppm v methyl amine 40 ppm v Energy (wavenumbers cm -1 )

16 Example of Outgassing Bases in Tape Products Tape Sample C Ammonia Standard Ammonia detected in outgas after 2 minutes. Fully outgassed at 245 ng/cm 2 or 32 ppm w after 30 minutes. FTIR outgassing spectra of a tape sample and standard at 85 o C Cummulative Outgassing Concentration (ng/cm2) :00 0:14 0:28 0:43 0:57 1:12 Time (hr:min)

17 FTIR Detection of Semi-Volatiles Collection Time < 2 minutes Octamethylcyclotetrasiloxane 10 ppm v Absorbance ethylhexyl acrylate 21 ppm v phenol 10 ppm v Energy (wavenumbers cm -1 )

18 Example of Outgassing Semi- Volatiles in Tape Products Tape Sample D Siloxane (OMCTS) Standard Siloxanes detected in outgas after 2 minutes. Fully outgassed at 20 ng/cm 2 or 2 ppm w after 30 minutes. 25 FTIR outgassing spectra of a tape sample and standard at 85 o C Note: OMCTS is a surrogate standard for all siloxanes through the 800 cm -1 band. Cummulative Outgassing Concentration (ng/cm2) :00 0:07 0:14 0:21 0:28 0:36 0:43 0:50 0:57 1:04 Time (hr:min)

19 Simultaneous Detection of Multiple Compounds in Tape Samples 3 Cummulative Outgas Concentration (ppmv) acetic acid (MA) ammonia (MB) methacrylic acid (MA) siloxanes (MC) 0 0:00 0:07 0:14 0:21 0:28 0:36 0:43 0:50 0:57 1:04 Time (hr:min)

20 FTIR Static Headspace Can quantitate and speciate, in a timely manner, molecular compounds that are outgassed from materials destined for the hard disk drive. Useful on manufacturing floor for routine evaluation of semi-finished or finished goods for unwanted contaminants and control charting. Useful in product development and product certification activities.