Numerical solution to the concentration dependent diffusion equation has been developed to study the redistribution of two-dimensional implanted profile in silicon below an ion-etched and a chemically-etched mask edges after thermal treatments. The implanted profile can either be a Gaussian or Pearson Ⅳ distribution. Results show that the lateral extension of boron ions is mainly determined by the initial conditions for a non-ideal masking

it can be as twice wide as that of the vertical direction

however

movement of lateral junction depth after a thermal treatment at a temperature lower than 1200℃ for less than 40sec is insignificant

therefore

the lateral junction will remain unchanged for a typical RTA process for the boron implanted sample. However

in the vertical direction

the junction depth will increase about 5% for 30 seconds diffusion at a temperature only 1100℃.