As the main step in forming p- and n-doped regions during the manufacture of integrated transistor circuits, controlled amounts of Group III, IV and V elements are introduced into the silicon substrate material in very low „dopant“ concentrations. 

Although the flowrates of dopants used in ion implantaion are relatively low, the gases used are very toxic and require scrubbing. While most of the contaminants are exhausted from the Ion Source of the implanter, it is also common for both Ion Source and Wafer Chamber to be connected to the CLEANSORB dry bed absorber.

Ion Implantation Process Typical Gases Used
Medium Current AsH3, PH3, BF3, SiF4, GeF4
High Current
High Energy
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