The preparation of polysilicon films on highly boron doped silicon substrates and their effects on Cu out-diffusion.

The behavior of copper (Cu) diffusion at different storage temperatures of heavily boron-doped silicon substrates is investigated. The surface Cu concentration of the substrate with quantitative Cu contamination exhibits an initial increase followed by a subsequent decrease upon storage at 25 °C and 85 °C. The surface Cu, originating from the out-diffusion, can be effectively removed through RCA cleaning.