Performance of p+layer formed by B diffusion using boron paper

This paper presents a novel boron diffusion process using boron paper as the boron source to form a p + layer. It was found that sheet resistance was invariable with changing the distance between boron paper and Si wafers, and diffusion uniformity was the best at a distance of 0.3 cm. Sheet resistance (R s ) decreased with increasing diffusion temperature, showing a value of 6.9 Ω/□ at 1050 °C with a high diffusion uniformity of 99.173%. The junction depth increased from 195 nm to 517 nm with diffusion temperature raised from 900 °C to 1050 °C. The influence of diffusion time on the performance of B diffusion from boron paper was similar with that of temperature.