First-principles study of non-radiative carrier capture by defects at amorphous-SiO2/Si(100) interface

Defects have a significant impact on the performance of semiconductor devices. By using the first-principles combined with one-dimensional static coupling theory approach, we have calculated the variation of carrier capture coefficients with temperature for the interfacial defects $\textit{P}_{b0}$ and $\textit{P}_{b1}$ in amorphous-SiO$_2$/Si(100) interface}. It is found that the geometrical shape of $\textit{P}_{b0}$ and $\textit{P}_{b1}$ defects undergo large deformations after capturing carriers to form charged defects, especially for the Si atoms containing a dangling bond. The hole capture coefficients of neutral $\textit{P}_{b0}$ and $\textit{P}_{b1}$ defects are largest than the other capture coefficients, indicating that these defects have a higher probability of forming positively charged centres. Meanwhile, the calculated results of non-radiative recombination coefficient of these defects show that both $\textit{P}_{b0}$ and $\textit{P}_{b1}$ defects are the dominant non-radiative recombination centers in the interface of a-SiO$_2$/Si(100).