We have investigated the effects of pouring deionized water onto a silicon (Si)/silicon-dioxide (SiO2) system wafer to repair plasma-induced damage, We found that the distribution of repair effectiveness across; the wafer was not uniform but depended strongly on both the pouring method and where on the wafer the water was poured. When the water was poured onto a rotating plasma-damaged wafer, the damage was most effectively repaired in the areas onto which the water was poured, and the effect decreased sharply with increasing distance from these areas. We propose a simplified hypothesis: some of the H+ ions produced by the friction between the water and the SiO2 migrate to the Si-SiO2 interface and passivate the dangling bonds (which are related to plasma damage) at the interface.