SiREM Photonics is dedicated to the development of optical remote sensing quantitative measurement methods and instrumentation for continuous environmental monitoring (CEM) and continuous process monitoring (CPM) for semiconductor manufacturing. Custom designed and built compact optical spectrometers can be integrated within a gas sampling or data analysis/streaming automation platform which allows for complete online environmental and/or process monitoring. As most gas and aerosol molecules absorb light, proportional to their concentration, the presence of specific compounds can be determined by their spectral patterns providing real-time monitoring data of emissions.

Project services include global field measurement services, instrument design, implementation, installation, and maintenance along with professional training and chemistry consultation, data interpretation, management and reporting for a wide variety of industrial sectors.

Examples of Sectors for Photonics Services:

  • Semiconductor – House and point-of-use abatement testing and chemistry consultation, house thermal oxidizer abatement testing; wet and dry process tool emissions testing; development of ultra-sensitive real-time measurement methods and instrumentation for greenhouse gases, cleanroom airborne molecular contaminants and wet process exhausts of acids, amines and VOCs; installation/maintenance/training of CEM instrumentation, worker exposure monitoring and gas cabinet tracer testing; R&D for process development.
  • Oil/Gas and Petrochemical – Fence-line and ambient air station measurement method development, installation, operation, and maintenance; process emissions testing and control; continuous emissions monitoring (CEM) instrumentation and data management, installation, and operation of continuous, real-time particulate monitoring systems.
  • Regulatory Agencies and Research Organizations – Development and validation of new sub-ppbv level measurement methods for air pollutants; fence-line and ambient air station monitoring.
  • Cement, Incinerator, Fertilizer and Electrical Power – Abatement system monitoring; installation/maintenance training of CEM instrumentation; ambient air and pond monitoring; development of measurement methods and instrumentation for low-level (pptv) monitoring.

 Photonics Technologies

  • Open-path and extractive Fourier transform infrared (FTIR) spectroscopy
  • Extractive tunable diode laser (TDL) and quantum cascade laser (QCL) spectroscopy
  • Open-path and extractive ultraviolet (UV) absorption spectroscopy
  • Gas chromatography (GC) and quadrupole mass spectrometry (QMS)
  • UV and IR based real-time sensor development involving pulsed and LED light sources, bandpass filtering, and high-speed detectors

Representative Examples of Photonics Custom Chemistry Projects

The examples below highlight some of the key projects that were designed in conjunction with the client for complex monitoring and data management solutions.

Measurement Methods/Technology Development and Integrated Systems & Services for the Semiconductor Industry

Airborne Molecular Contaminant Monitoring. Developed and deployed enhanced extractive FTIR and QCL measurement methods for extremely low (pptv) level airborne molecular contaminants in cleanrooms that may impact process wafers. The monitoring technique focuses on the primary airborne chemical by-products, HF (for fluorinated organic and inorganic compounds), HCl (for chlorinated organic and inorganic compounds) and NH3 (for amines), as well as select VOCs and HNO3.

Semiconductor III-V Process Chemistries and Exhausts. Developed and validated real-time measurement methods for wet and dry semiconductor substrate clean and etch processes. Primary techniques focused on attenuated total reflectance (ATR) monitoring via FTIR and QCL of aqueous baths for arsenic, gallium, and indium-based compounds, as well as extractive FTIR/QCL tool exhaust monitoring of arsenic and gallium-based vapors and aerosols.

Greenhouse Gas Monitoring per EPA Rule 40 CFR Part 98, Subpart I. In collaboration with Texas Instruments (per EPA Method 301) an enhanced extractive FTIR measurement method for monitoring very low (sub-ppbv) levels of greenhouse gases (GHGs) emitted from semiconductor fab acid stacks was developed and validated. Further collaboration with the International Sematech Manufacturing Initiative and EPA to have the technique written into 40 CFR Part 98, Subpart I as an approved measurement method toward reporting GHG emissions.

Semiconductor Process Effluents, Abatement Systems and Stacks throughout the US. Developed and validated (per EPA Methods 301 and 320) extractive FTIR measurement methods for monitoring low (ppbv) levels of HF, and other inorganic acids, as well as fluorinated greenhouse gases, volatile organics, ammonia, and related amines. A multitude of stacks, wet scrubbers, thermal oxidizers, point-of-use abatement systems and end-of-pipe tool exhaust emissions have been tested over 20 years.

FTIR-CEM Monitoring of Acid Stack Emissions at a Texas Semiconductor Facility. Developed, installed, operated, and maintained an FTIR based CEM for continuous monitoring of acid gas emissions (including HF, HCl, H2SO4, SiF4 and various other PFCs) out of two stacks in a scrubber yard at a semiconductor facility in Dallas, Texas. The system included an automated gas handling manifold that switched between emission sources, house nitrogen and calibration gases for on-the-fly data QA/QC checking and reporting.

Real-time Fluorine Monitoring at Semiconductor Process Effluents, Cleanrooms, Sub- fabs and Stacks. In collaboration with Motorola, a new technology for continuous real-time monitoring of molecular fluorine (F2) produced from CVD chamber cleans and various dry etch tools was developed. Measurement protocol for the technique (called fluorine chemiluminescence) was written to incorporate into an International Sematech document that provides guidelines for the industry to follow in characterizing process tool emissions. This technique has been further utilized outside of process tool emissions, including worker exposure monitoring in clean rooms/subfabs and characterizing wet scrubber, as well as stack, emissions to gauge environmental impacts.

Perfluorocarbon (PFC) Abatement Optimization and Efficiency Characterizations. Provided ongoing R&D design, chemistry consultation and measurement services to a prominent abatement system manufacturer in order to provide the industry with a new low-maintenance, high-efficiency scrubber/burner/scrubber point-of-use abatement system optimized for reducing PFC and GHG emissions. The ongoing work occurs mostly through in-house laboratory testing with some on-site field testing.

Ambient Air, Fence-line, and Continuous Environmental Monitoring

Perimeter Landfill and Oil/Gas Refinery Locations. Developed an extractive quantum cascade laser (QCL) based ambient air monitoring station capable of continuous, real-time detection of H2S and CH4 to levels on the order of 10 ppbv. The monitoring station is fully automated and includes a meteorological tower with wind speed/direction and temperature/pressure sensors to identify and track emission sources and plumes.  Automated data QA/QC routines, including gas spiking audits, and real-time data streaming (with 3-minute data rates) is featured.

Houston Regional Monitoring (HRM) Network, Houston, TX. An extractive FTIR CEM ambient air monitoring system that operated on a continuous basis was developed and in use for 10 years as part of the HRM network. The monitoring station included a dual-cell FTIR spectrometer configured with long path lengths, an integrated meteorological station and LAN for remote control and data archival, all located in a climate-controlled shelter next to an elementary school. Pollutants monitored, validated, and reported included VOCs, HRVOCs, BTEX, NH3, CO and freons.

Ambient Air Community Monitoring Station, Seabrook, TX. Developed and program management of an extractive FTIR CEM ambient air monitoring system that operated on a continuous basis for 4 years at a public park in Seabrook, Texas. The monitoring station included a dual-cell FTIR spectrometer configured with long path lengths, an integrated meteorological station and LAN for remote control and data archival. Pollutants monitored, validated, and reported included VOCs, HRVOCs, BTEX, NH3, CO, freons and O3.

Petrochemical Facility, Rayong, Thailand. A full perimeter open path FTIR (OP-FTIR) fence-line monitoring system for 40+ VOCs was designed and installed at a petrochemical facility in Rayong, Thailand. The system entails three OP-FTIR spectrometers, complete with auto scanning mounts, and a series of 14 retroreflecting arrays, along with two meteorological sensor towers and LAN for remote control and data analysis/archival. Installation of the complete field system, plant personal training, acceptance tested and certified the installation against NIST traceable calibrated gas standards was completed. Additional support of operation and maintenance and spectral analysis was conducted remotely as needed.

Petrochemical Facility, TX. Spectral analysis services and field operation/maintenance support for an ongoing program consisting of a single fence-line OP-FTIR spectrometer and a series of four retroreflecting arrays. Data are integrated with met data and an auto scanner to help locate and reduce 1,3-butadiene releases from the plant.

Texas Oil/Gas Refinery Measurement Services, Houston, TX. Program management of a series of OP-FTIR field measurements and data analysis/reporting for a large EPA mandated study (2 years) of ground and elevated flare emissions near Houston, Texas. Combustion efficiencies were empirically determined over a test matrix of flare operating parameters and fuel compositions.

Contact us for more details on these projects or consultation on how Photonics can be applied to your environmental and/or process monitoring applications

Curt Laush, Ph.D. Photonics Laboratory Manager claush@siremlab.com
Brent Pautler, Ph.D. Chemistry Services Manager bpautler@siremlab.com