The effects of rapid thermal annealing (RTA) and laser annealing (LA) on the activation and diffusion of ion-implanted boron in Si substrate have been investigated. The implant and anneal regimes, forming good shallow junctions, were presented. The Si+-preamorphized samples boron implanted with a high dosage showed largely enhanced diffusion in RTA processing. The LA process serves as an excellent scheme to effectively activate the dopant and suppress the anomalous diffusion because of its very high heating rate. A high-quality p+/n junction with a leakage current density lower than 2 nA/cm 2 and a forward ideality factor of about 1.01 was formed by laser processing.