DOPING OF PHOSPHORUS AND BORON INTO SILICON BY SOLID-PHASE DIFFUSION AT LOW-TEMPERATURES (LESS-THAN-650-DEGREES-C)

The diffusion of phosphorus and boron into silicon at lower than 650-d egrees-C was achieved. Spin-coated glass was used for the diffusion so urce and samples were heated with a tungsten halogen lamp. The key to diffusing these impurities into silicon at such low temperatures is to decrease the temperature of silicon without reducing some of the ligh t radiated from the halogen lamp. Impurity concentrations at the silic on surface were 1-2 x 10(20) cm-3 at 620-720-degrees-C. These impuriti es diffused into silicon typically at least 0.1 mum from the silicon s urface after 40 min of 620-degrees-C annealing.