Ultra Clean Holdings, Inc. designs, develops, prototypes, engineers, manufactures, and tests production tools, modules, and subsystems for the semiconductor and display capital equipment industries in the United States and internationally. The company provides subsystems, such as wafer cleaning modules; chemical delivery modules that deliver gases and reactive chemicals in a liquid or gaseous form from a centralized subsystem to the reaction chamber; frame assemblies, a support structures fabricated from steel tubing or folded sheet metal; process modules, a subsystems of semiconductor manufacturing tools that process integrated circuits onto wafers; and top-plate assemblies. It also offers various industrial and automation production equipment products; gas delivery systems, which include one or more gas lines, such as weldments, filters, mass flow controllers, regulators, pressure transducers and valves, component heaters, and an integrated electronic and/or pneumatic control system; fluid delivery systems consists of one or more chemical delivery units, including PFA tubing, filters, flow controllers, regulators, component heaters, and an integrated electronic and/or pneumatic control system; precision robotic systems that are used when accurate controlled motion is required; and other high level assemblies. In addition, the company provides tool chamber parts cleaning and coating services; micro-contamination analysis services for tool parts, wafers and depositions, chemicals, cleanroom materials, deionized water, and airborne molecular contamination; and analytical verification services for process tool chamber part cleaning. It primarily serves original equipment manufacturing customers in the semiconductor capital equipment and semiconductor integrated device manufacturing industries, as well as display, consumer, medical, energy, industrial, and research equipment industries. The company was founded in 1991 and is headquartered in Hayward, California.