Hydrogen passivation for reduction of SiO2/Si interface state density using hydrocarbon-molecular-ion-implanted silicon wafers

The reduction in the density of SiO2/Si interface state (D-it) in the isolation region and transfer transistor gate oxide is necessary to improve the performance of complementary metal-oxide semiconductor (CMOS) image sensors. In this study, we demonstrated that a hydrocarbon-molecular-ion-implanted epitaxial silicon wafer can reduce the D-it and Pb-0 center density in SiO2/Si interface regions analyzed by quasi-static capacitance-voltage and electron spin resonance measurements, respectively. The D-it and Pb-0 center density of wafers without hydrocarbon molecular ions increased after annealing at 700 degrees C. On the other hand, the D-it and Pb-0 center density of wafers implanted with hydrocarbon molecular ions decreased after annealing at 700 degrees C. We also estimated the activation energy to be 1.67 eV for the hydrogen termination reactions with hydrogen molecules and Si dangling bonds at the SiO2/Si interface. The termination effects of the hydrocarbon-molecular-ion-implanted epitaxial silicon wafers can contribute to the high electrical performance of CMOS image sensors.