Two-level charge pumping (CP) measurements have been used for the study of a single trap situated at the SiO2/Si interface of sub-100 nm metal-oxide-semiconductor transistors (50 nm length). At room temperature, we have measured the emission time constant (tau) of the single trap and verified that the generation-recombination process was consistent with the Shockley-Read-Hall theory. Temperature-dependent CP measurements have been used to determine the thermal variation of the emission time constant. We show that an Arrhenius plot of the emission time constant versus the temperature (tauxT(2) vs 1/T) allows the determination of the capture cross section and energy position of the trap within the silicon band gap. The single trap, which has been characterized here, is shown to be the well-known donor P-b0 center (dangling bond) at the SiO2/Si (100) interface. (C) 2003 American Institute of Physics.