It is shown that plasma‐enhanced chemical‐vapor deposition (PECVD) of thin SiO2on Si wafers followed by rapid thermal annealing (RTA) can result in very high effective carrier lifetime (≳5 ms) and extremely low surface recombination velocity (≤2 cm/s). Thin SiO2(∼100 A˚) layers were prepared by direct PECVD at 250 °C and RTA was performed at 350 °C in forming gas. Detailed metal‐oxide‐semiconductor analysis and model calculations showed that such a low recombination velocity is the result of moderately high positive oxide charge (5×1011–1×1012cm−2) and relatively low midgap interface‐state density (5×1010–1×1011cm−2 eV−1). RTA was found to be superior to furnace annealing, and a forming gas ambient was better than a nitrogen ambient for achieving a very low surface recombination velocity. Some degradation in the surface recombination velocity or effective lifetime was observed. It is found that a PECVD SiN cap on top of the thin SiO2not only suppressed this degradation but also enhanced the effective lifetime.