The furnace stacks have a total of four locations capable of accepting furnace tubes up to six inches in diameter. The furnaces are computer controlled with automatic insertion and withdrawal. They are capable of processing materials up to 1350oC. The furnaces are used for a variety of processing, including diffusion, oxidation, and annealing. Each furnace tube is dedicated to a particular process to prevent cross contamination. The bulk of the furnaces extend outside the S.M.A.R.T. Laboratory class 100 clean room to conserve space and reduce particulate contamination in the clean area.