The need for a particulate and contamination-free wafer surface requires frequent cleaning. The major types of cleaning are:
- Deionized water and detergent scrubbing.
- Solvent: isopropyl alcohol (IPA), acetone, ethanol, terpenes.
- Acid: HF, H2SO4 and H2O2, HCl, HNO3, and mixtures.
- Caustic: NH4OH
The following are the potential hazards of cleaning.
- Possible employee exposure to acid and caustic solutions used during cleaning.
- Typical acids may include mixtures of HF, H2SO4, H2O2, HCl, and HNO3.
- Caustic solutions include mainly NH4OH.
- Occupational Health Guidelines for Chemical Hazards. US Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 81-123, (1981, January). Provides a table of contents of guidelines for many hazardous chemicals. The files provide technical chemical information, including chemical and physical properties, health effects, exposure limits, and recommendations for medical monitoring, personal protective equipment (PPE), and control procedures.