The effects of gas species on the charge build-up in reactive ion etching (RIE) have been investigated. The charge build-up was evaluated using metal/nitride/oxide/silicon (MNOS) capacitors and metal/oxide/silicon (MOS) capacitors. It was found that etching with electronegative gases such as O2 and CF4 results in considerable charge build-up. The spatial distribution of plasma parameters was diagnosed using a Langmuir probe. It was found that the spatial distribution of plasma parameters is non-uniform in plasmas of negative gases, while it is uniform in H2, He, Ar, and Xe gas plasmas. The results suggest that we must take the effect of the gas species into consideration for the nonuniformity in a plasma, which causes the significant charge build-up. Models that can be used to explain the effect of gas species are discussed. It was also found that the charge build-up can be drastically reduced by adding H2 gas to negative gases.