Abstract
The rapid diffusion of phosphorus and boron in WSi2 has been characterized using a novel Schottky Barrier test structure. Diffusivity of both dopant species was about 4-5 orders of magnitude higher than that reported in polycrystalline silicon. The dopant diffusivity is strongly dependent on the silicide morphology. Diffusivity measured in low temperature pre-annealed silicide is approximately an order of magnitude higher than in silicide pre-annealed at 1050°C. The dopant diffusivity in oxide lined silicide test structures was 3-4.3x10-10 cm2 s-1 at 900°C while polycrystalline silicon lined structures exhibited a higher value at 900°C of 1.5x10-9 cm2s-1. This is attributed primarily to greater segregation of dopant to the oxide-silicon interface compared to the polysilicon-silicide interface. Boron exhibited a higher diffusivity in WSi2 with diffusivity in the range 4x10-9 cm2s-1 - 1x10-8 cm2s-1 at 900°C.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have