A proposal for energy saving in semiconductor fabs

This paper describes measurement of the energy consumption of diffusion furnaces and proceeds to propose several methods for energy saving. Measurements showed that cooling water consumes 71% of the energy, exhaust air 11% and dry coil (heat transferred to clean room air) 18%. In terms of cost (in Yen), cooling water accounts for 32%, exhaust air 46% and dry coil 22%. Proposals are raised for reducing the energy consumption of the furnace to less than a half of conventional ones by: employment of double layer cooler; replacement of exhaust from clean room air by partially treated air; and employment of heat insulation material for the furnace casing