Advanced boron-based ultra-low energy doping techniques on ultra-shallo junction fabrications

The focus of this paper is a comparative study of the advanced boron-based ultra-low energy (ULE) doping techniques on ultra-shallow junction (USJ) fabrications, including beam-line atomic ¹¹B implant, BF₂, B₁₈H₂₂, C₂B₁₀H₁₂ molecular implants, cluster B implant, and B₂H₆ and BF₃ PLAD implants. It has been found that B₂H₆ PLAD and B₁₈H₂₂ molecular implants demonstrate the best R_S-x_j and abruptness characteristics. Beam-line BF₂ implant shows poor R_S-x_j characteristics due to its serious RIE effect by F species. Cluster B implant shows the worst R_S-x_j characteristics and a very rough surface. Both are attributed to its serious self-sputtering effect because of its much larger and heavier ion species although further optimization may lead to improvement.