Diffusion kinetic of hydrogen in CH3O-molecular-ion-implanted silicon wafer for CMOS image sensors

The association and dissociation behavior of hydrogen in the implanted region of a CH3O cluster were investigated for high-performance CMOS image sensors. Two hydrogen peaks were observed in the CH3O-implanted region after epitaxial growth and heat treatment. The difference in the depths of the two peaks accords with the difference in the depth of carbon-cluster-related and new extended stacking fault defects. Thus, we calculated the activation energies of the association and dissociation of hydrogen, assuming a dissociation reaction for the first peak, formed at a small depth from the surface of the silicon substrate, and a simple reversible reaction for the second peak, formed at a large depth from the surface of the silicon substrate. The dissociation activation energy corresponding to the first peak was 0.75 ± 0.03 eV. This activation energy indicates that the hydrogen associated with the first peak forms a binding state with a carbon and silicon self-interstitial cluster (C/I cluster). On the other hand, the binding energy corresponding to the second peak was calculated to be 0.78 eV, which was close to the C-H2 binding energy. Consequently, the CH3O-implanted region forms a binding state with hydrogen and a C/I cluster or a C-H2 binding state.