Occupational Safety and Health Administration OSHA

Alert: Due to routine maintenance on the OSHA website, some pages may be temporarily unavailable.
To report an emergency, file a complaint with OSHA or ask a safety and health question, call 1-800-321-6742 (OSHA).


Alloying and Annealing

After the metallized interconnections have been deposited and etched, a final step of alloying and annealing may be performed. To perform alloying, the metallized substrate is placed in a low-temperature diffusion furnace. Usually aluminum is placed in the furnace to form a low-resistance contact between the aluminum metal and silicon substrate. Finally, either during the alloy step or following it, the wafers are often exposed to a gas mixture containing hydrogen in a diffusion furnace at 400-500ºC. This annealing step is designed to optimize and stabilize the characteristics of the device by combining hydrogen with uncommitted atoms at or near the silicon-silicon dioxide interface.

The following are the potential hazards of alloying and annealing.


Potential Hazard

  • Possible employee exposure to various metals, aluminum being the most common.

Possible Solutions

  • Identify metal hazards and perform appropriate exposure evaluations.
    • Perform exposure measurements for the compounds used.
    • Keep exposures below acceptable exposure levels.
  • Address all dermal exposures.
  • Provide appropriate ventilation to reduce metals concentration levels in the air.
  • Provide PPE as appropriate to prevent contact. [29 CFR 1910 Subpart I]
  • Use respiratory protection when necessary to further reduce exposure and protect employees. [29 CFR 1910.134]
  • Maintain adequate housekeeping to remove unwanted metals and reduce concentration levels.

Additional Information

OSHA Safety and Health Topics Pages:

Back to Top

Thank You for Visiting Our Website

You are exiting the Department of Labor's Web server.

The Department of Labor does not endorse, takes no responsibility for, and exercises no control over the linked organization or its views, or contents, nor does it vouch for the accuracy or accessibility of the information contained on the destination server. The Department of Labor also cannot authorize the use of copyrighted materials contained in linked Web sites. Users must request such authorization from the sponsor of the linked Web site. Thank you for visiting our site. Please click the button below to continue.