Advantageous Decaborane Ion Implantation for Ultra-shallow Junction of PMOSFETs Compared with Boron Monomer Implantation into Germanium Preamorphized Layer

We report the advantage of the decaborane (B₁₀H_x ⁺) ion implantation for sub-40-nm-gate-length PMOSFETs compared with conventional boron monomer ion implantation into pre-amorphized layer. PMOSFETs with decaborane ion implantation have a 5% higher on-current than those with boron monomer into pre-amorphized layer. In addition, the threshold voltage fluctuation of the PMOSFETs is also smaller. This high performance of the PMOSFETs is caused by high carrier activation of the decaborane ion implanted layer. We speculated that the high carrier activation results from the surface amorphous layer and undamaged crystal substrate with smooth amorphous/crystal interface due to the cracking of decaborane