350D

The Varian 350D is a medium current implanter. The Varian 350D was the industry-standard predecessor from which the 300 XP evolved. The Varian 350D was the tool of choice during the early 1980's.^[1]

Ion implantation uses an ion source, beamline, mass analysis and dose control to place dopants into a wafer without relying on thermal diffusion during the introduction step. The process generally selects an ion species, accelerates the ions to the desired energy, scans or steers the beam across the wafer, and measures delivered charge to control dose.

Ion implanters are used in front-end semiconductor fabrication after films and masking layers define where dopants should enter the wafer. Ion implantation is commonly followed by thermal steps that activate dopants and repair implantation damage, and it is coordinated with lithography, deposition, and etch modules that shape the device structure.

Ion implantation is used to form doped regions in semiconductor devices. Typical applications include well formation, threshold adjustment, source and drain formation, channel engineering, contact region doping, and related processes in research and production wafer fabrication.