Hydrogen-Ion Implantation at 300°C Used to Passivate Charge-Trapping Defect States in Polycrystalline-Silicon Films

Passivation of charge-trapping defect states of 47-nm-thick-poly-crystalline silicon, poly-Si, films with hydrogen ion, $\mathrm{H}^{+}$, implantation at 2 keV at $300^{\circ} \mathrm{C}$ is reported. When $6 \times 10^{14}-\mathrm{cm}^{-2}-\mathrm{H}^{+}$-implanted poly-Si films were implanted with boron ions, $\mathrm{B}^{+}$followed by post heating at $350^{\circ} \mathrm{C}$ for $30 \mathrm{~min}$, the sheet resistivity, $\rho_{\mathrm{s}}$, decreased from $3.4 \times 10^{5}$ to $1.6 \times 10^{4} \Omega / \mathrm{sq}$ as the $\mathrm{B}^{+}$dose increased from $5 \times 10^{13}$ to $3 \times 10^{14} \mathrm{~cm}^{-2}$, while high $\rho_{\mathrm{s}}$, which decreased from $1.9 \times 10^{7}$ to $2.6 \times 10^{4} \Omega /$ sq was observed when $\mathrm{B}^{+}$implantation followed by the post heating were applied to as-fabricated poly-Si films with no $\mathrm{H}^{+}$implantation. The numerical analysis of change in $\rho_{\mathrm{s}}$ revealed that the $\mathrm{H}^{+}$implantation at $300^{\circ} \mathrm{C}$ decreased the density of charge trapping defects from $1.05 \times 10^{13}$ (as fabricated) to $4.7 \times 10^{12} \mathrm{~cm}^{-2}$.