Implantation temperature effect on polycrystalline silicon by ion shower doping

We present a new doping technique using an ion shower doping system with a bucket ion source. Phosphorus atoms were implanted in polycrystalline silicon from room temperature to 300 °C. Sheet resistances were significantly reduced by raising the implantation temperature. With a crystal fraction of 85%, sheet resistance was 5×102 S−1/⧠ as implanted. These effects were not due to pure thermal annealing by ion beam heating. A significant improvement was found in sheet resistance as a result of averaging the impurity profile by radiation enhanced diffusion and low temperature recrystallization of the implanted region by collision of atoms.