Phone: þ82 2 2220 0387, Fax: þ82 2 2292 3523We investigated the effects of NH 3 plasma power on characteristics of low-temperature silicon nitride thin films for application of a gate spacer. SiN x thin film was deposited on a Si(100) substrate by remote plasma atomic layer deposition (RPALD) using trisilylamine (TSA) as a Si precursor and NH 3 gas as a reactant. NH 3 remote plasma was analyzed with optical emission spectroscopy (OES) and it largely consisted of NH and H. As the plasma power increased, more NH and H radicals were generated and a proportion of NH radicals in the plasma increased, which resulted in the slight increase of the high-N content and low-H content in SiN x thin film. The low-H content with nearly stoichiometric SiN x thin films improve etch rate properties. The densities of RPALD SiN x thin film were 2.7 g cm À3 and almost the same regardless of plasma power.RPALD SiN x thin films showed a low leakage current density of 10 À7 A cm À2 at 2 MV cm À1 and a breakdown voltage of approximately 8 MV cm À1 .