Handling and Remediation of Toxic Materials By Adam Schmolling April 29, 2016 Abstract: The semiconductor industry uses a number of harmful chemicals. This presentation covers the handling of these chemicals.

This presentation will: Introduce the chemicals, and what they do to humans. Outline how these chemicals are used in the semiconductor manufacturing process. Explain how manufacturers are handling these chemicals. Cover environmental issues in third world countries. Address what manufacturers are considering to further clean up the semiconductor manufacturing process.

Some of the harmful chemicals used: AcetoneArsenicArsineBenzeneCadmium Methyl Chloroform PhosphineToluene Trichloroethylene Trichloroethylene

Acetone An industrial solvent. Used in the polishing of silicon wafers. OHSA PEL: 500 ppm OSHA STEL: 750 ppm OSHA CEILING: (immediate danger) 3000 ppm

Arsenic Used in rat poison. Used as a dopant in semiconductors. OSHA PEL: 10 micro grams / m 3

Arsine Gas made with Arsenic Used for vapor deposition In route through inhalation Garlic / fishy smell, which does not provide enough warning which does not provide enough warning Flammable and highly toxic OSHA PEL: 0.05 ppm

Benzene Used in photo-electrochemical etching Has the famous Benzene ring Sweet aromatic odor Used extensively in assorted industries Liquid at room temperature, but evaporates into air quickly. evaporates into air quickly.

Cadmium Used as a dopant Banned by EU Causes a number of ailments

Methyl Chloroform Used in washing of silicon wafers OSHA PEL: 350 ppm OSHA STEL: 450 ppm (for 15 minutes) Immediate danger: 700 ppm

Phosphine Used in vapor deposition Flammable, toxic and Pyrophoric Immediate danger limit: 0.3 ppm

Toluene Used for chemical vapor deposition Sweet, pungent odor, which provides Enough warning. OSHA PEL: 200 ppm OSHA ST: 500ppm (for 10 minutes) Gas at room temperature

Trichloroethylene Used for wafer washing Liquid at room temperature May decay into Dichloroacetylene, which is explosive and a neurotoxin. which is explosive and a neurotoxin. OSHA PEL: 100 ppm

Assorted Acids Hydrofluoric Acid Sulfuric Acid Nitric Acid Orthophosphoric Acid Hydrochloric Acid Hydrobromic Acid

Silane Used in chemical vapor deposition Silane leaks can be very dangerous Spontaneously ignites when mixed with air (without flame or spark.) with air (without flame or spark.)

Pyrotechnics

Pyrotechnics

Pyrotechnics

Residue Leaves a brown residue which is composed of SiH 2 O which is composed of SiH 2 O and a white residue composed and a white residue composed of SiO 2 of SiO 2

Silane explosions in the semiconductor industry 1976, Germany 1989, Japan 1990, Japan 1992, United States 1996, Japan 2003, United States 2005, Taiwan

Chemical Handling Concerns 1981: Leaky underground storage tanks in San Jose, CA. In 1990, 70 female workers in Scotland brought a lawsuit against National Semiconductors. 1995: The American Journal of Independent Medicine studied miscarriage among semiconductor industry workers. 1996: IBM employees brought a lawsuit against various chemical manufacturers. 2014: Samsung publically apologized for worker deaths.

Samsung Worker Deaths and Illnesses in Korea

Handling of Dangerous Wastes There is a three part strategy for dealing with the waste chemicals of semiconductor manufacturing: 1. Waste Elimination 2. Waste Reduction 3. Waste Treatment

Gas Monitoring PPM detectors in ventilation, gas cabinets, enclosures etc. Flammable gas monitoring Containers of hazardous gasses are isolated

State of the Art Gas Monitoring System

Actually

Plant Exhaust System

Making things “Green” Fairchild Semiconductors is striving to become more environmentally friendly. Texas Instruments is very proud of their LEED certified fabrication plant in Richardson, Texas.

PPM Limits (Per Product)

PPM Limits Continued

Ultra Pure Water (UPW) is used It takes 1600 gallons of tap water to make 1000 gallons of UPW It takes 1500 gallons of UPW to create a single 30cm wafer A typical fabrication plant can use 4 million gallons of UPW water per day. Water Use

This is an environmental, as well as an economic concern. Especially in China, who is a leader of semiconductor manufacturing, and also has a growing thirst for clean water. Sometimes environmental regulations are skirted.

Conclusion The semiconductor industry uses a number of dangerous chemicals. These chemicals must be carefully handled, and care must be taken to avoid contaminating the environment or endangering workers.

References [1]electronicstakeback.com [online] Available: electronics/wheres-the-harm-component/ [2]electronicstakeback.com [online] Available: apologizes-to-semiconductor-workers-who-contracted-cancer-promises- compensation/ [2]chinawaterrisk.org [online] Available: things-you-should-know-about-water-and-semiconductors/ [3]prevor.com [online] Available: semiconductors-industry

References [5]cnx.org [online] Available: Impact-of-th [6]semi.org [online] Available: %E2%80%9D-cost-30-less-%E2%80%94-and-will-save-4-million-year-0 [7]controlinstruments.com [online] Available: gas-monitoring-throughout-semiconductor-manufacturing-facility [8]S. Virgil, “Environmental Management of Wastes in the Semiconductor and Electronics Industries,” Proceedings of International Symposium on Advanced Waste and Emission Management. Dec. 4, 2000 pp 2-7

Five Key Points Silane and Phosphane need no spark to ignite, but can spontaneously ignite when exposed to the atmosphere. If safety standards are skirted, workers can end up with Leukemia, liver problems, and a host of other long term ailments. The semiconductor industry currently consumes large quantities of water. Ways to reduce water consumption are continuously being investigated. The three level strategy to reducing dangerous waste is elimination, reduction, and treatment. Infinitesimally small amounts (0.05 – 0.3 ppm) of Arsine and Phosphine are lethal.