Silicon semiconductor wafer design, production: fumes with ultrafine particles (UFP)

List of chemicals used in the manufacture of semiconductors. Experts identify three basic steps needed to make semiconductors: crystal growing, wafer fabrication, and assembly.

However, there are many and varied interim processes within each of those stages.

(Hi stranger, a blog by Steven Van Hull, nicely illustrates and explains some semiconductor processes. We link to Mr. Hull’s blog because the images there may clarify issues associated with lasers, ultrafine particles (UFP), chemicals and silicon semiconductor manufacture.)

Our customers use our products in the semiconductor applications discussed in this post, including laser fume extraction and capture of renegade process fumes that include both particles and odors.

Composite wafers: silica + metals, chemicals, plastics, acids

Lasers are used in at least two aspects of the manufacture of semiconductors, cutting (saws may be used as well) and marking.

Cutting – Lasers may be used to cut the chips from the silica wafers after they undergo a variety of processes that involve chemicals, acids, metals – even plastics — to produce multiple chips on each wafer.

Marking– Near the end of manufacturing processes, semiconductors are marked with product identification and traceability codes.

Lasers can produce UFP

Processes that generate very high temperatures produce airborne UFP, including welding, 3D printers and lasers.

UFP are measured using the nanoscale, or nanometers.

A single nanometer is 1/1,000,000,000 (one billionth) of a meter.

If they’re so tiny, why do we care?

Nanoscale particles are invisible without special instruments.

However, they are inhalable.

Some researchers have found that UFP can be carried by the circulatory system from the lungs to other parts of the body, including the brain.

“As a result of their physical characteristics, inhaled UFPs differ from larger particles in their deposition patterns in the lung, their clearance mechanisms, and in their potential for translocation from the lung to other tissues in the body. Some animal studies have also demonstrated translocation of UFPs via the olfactory nerve to the brain.”

Understanding the Health Effects of Ambient Ultrafine Particles, HEI Perspectives, January 2013

Although the exact nature of the particles depends upon the material cut or marked by the laser, it may be the size of the particles is as relevant to their impact on human health as their actual substance.

A fume extractor equipped with a HEPA filter can capture small particles before they are spread through the work area.

In Current Intelligence Bulletin 65, NIOSH discusses engineering controls for exposure to nanoscale particles:

“HEPA filtration has been shown to be effective in capturing nanoscale particles and should be considered in situations where emissions may be regular, where processes are repeated, and where higher quantities are used in a way that may lead to emissions.”

Current Intelligence Bulletin 65, Occupational Exposure to Carbon Nanotubes and Nanofibers, April 2013

Another reason for fume extraction: lasers optics can be damaged by particles

Lasers must be calibrated to precisely produce the desired depth and width of incisions into any material; tolerances are extremely small.

Debris produced by use of the laser — without a fume extractor that pulls UFP away from the laser’s optical mechanisms — can adhere to the optics and make calibration difficult.

Dirty optics can also cause cleaning downtime and may even create hot spots on the lens that damage the laser.

Laser in your lab or production facility?

Sentry Air's Model 300 Portable Fume Extractor

Model 300 Portable Fume Extractor can be configured with HEPA filtration for particle capture and activated carbon filtration for chemical odors or acid gas fumes.

If you design and prototype semiconductors, you and your laser both deserve protective fume extraction.

We produce a range of portable fume extractors that don’t require dedicated ductwork.

Our most popular portable fume extractor is the Model 300.

Heavy-duty casters and a handle make it easy to push or pull the unit to the source of fumes.

For example, if your production processes are enclosed in cabinets that are periodically opened, creating a fume aerosol, you can easily move the fume extractor to the cabinet.

The unit is equipped with a pre-filter that prolongs the life of the main filters. Our quick-change pre-filter option insures work won’t be interrupted for long periods of time.

 

Renegade fumes?

If your facility does its best to control fumes and yet your place smells like a factory, it could be that fumes from various process machines are escaping into the broader room air.

Sentry Air's Model 700 Ambient Air Cleaner.

The Model 700 can be configured with four types of filters, including HEPA and activated carbon.

We offer two types of ambient air cleaners with multiple mounting and installation options, the Model 2000 and the Model 700.

Since the EPA’s NESHAP regulations may apply to your facility, both models can be useful tools in meeting those requirements

Shown to the left, the Model 700 is a powerful air purifier that can be suspended from the ceiling, mounted on an elevated stand, or attached to a wall-mounted shelf.

We’d love to talk with you

Mist collection, nano scale particle capture, acid gas applications — our products are used to help protect workers and equipment across many industries.

If you’re looking for fume extraction solutions for your semiconductor processes, please contact us.

Our Application Specialists can help you solve your fume problems. Call Sentry Air Systems at 800.799.4609, email sales@sentryair.com, visit our website, or fill out the feedback form below.

 

Resources – Health Hazards

A Guide on Health Hazards and their control in wafer fabrication facilities
http://www.mom.gov.sg/Documents/safety-health/factsheets-circulars/Handling%20Health%20Hazards%20and%20their%20Control%20in%20Wafer%20Fabrication%20Facilities.pdf

Fine and ultrafine particles emitted from laser printers as indoor air contaminants in German offices
http://www.ncbi.nlm.nih.gov/pubmed/22095199

Exposure to Inhalable, Respirable, and Ultrafine Particles in Welding Fume
http://annhyg.oxfordjournals.org/content/early/2012/04/26/annhyg.mes025.full.pdf+html

Understanding the Health Effects of Ambient Ultrafine Particles
http://pubs.healtheffects.org/getfile.php?u=893

Potential Hazards
https://www.bnl.gov/pv/files/pdf/art_170.pdf

Dicing of Gallium Arsenide (GaAs) Wafers with the Laser MicroJet® Challenges, Improvements and Safety Issues
http://www.synova.ch/fileadmin/user_upload/conferences/2002_Icaleo_Dicing_GaAs.pdf

Resources – Processes

Semiconductor device fabrication
http://en.wikipedia.org/wiki/Semiconductor_device_fabrication

National Emission Standards for Hazardous Air Pollutants (NESHAP) for Source Category: Manufacture of Semiconductors — Background Information for
Proposed Standards
http://www.epa.gov/ttn/atw/semicon/smatr_bid.pdf

Substrate Manufacture
https://www.osha.gov/SLTC/semiconductors/substratemfg.html

How are microprocessors made?
http://electronics.stevenvh.net/cpu/index.php