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Safety and Health Topics > Semiconductors > Gallium Arsenide > Ingot Growing: Ampoule Breakout Ingot Growing: Ampoule Breakout After the single-crystal GaAs ingot is grown within the sealed quartz ampoule, the quartz boat containing the ingot, plus the seed crystal, is removed from the ampoule, either by cutting off the sealed end of the ampoule with a wet circular saw, or heating and cracking the ampoule with a hydrogen/oxygen torch. The quartz ampoules are recycled by wet etching the condensed arsenic on the interior surface with HCl/HNO3 or H2SO4/H2O2. Potential Hazards Flammable Gases, Fire Arsenic Machinery Acid and Caustic Solutions Flammable Gases, Fire Potential Hazard Possible ignition of flammable gases, resulting in fire and/or explosion. Employees may also be exposed to gases above permissible limits. Possible Solutions See the Possible Solutions: Flammable Gases, Fire page. Use appropriate equipment, safety devices, and work practices associated with the hydrogen/oxygen torch. Acid and Caustic Solutions Potential Hazard Possible employee exposure to acid and caustic solutions used for etching ampoules for recycling. Solutions of HCl, H2SO4, HNO3, and H2O2 are commonly used. Possible Solutions See the Possible Solutions: Acid and Caustic page. Additional Information OSHA Health Guidelines pages: Hydrogen Chloride Hydrogen Peroxide

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