PECVD oxides are promising as low-temperature gate insulator for MOS devices. For the evaluation of their quality, PECVD oxides of 10nm–35nm are deposited by using different RF power frequencies (100KHz, 450KHz or 13.56MHz), a low plasma energy density (0.04W/cm2) and a mixture of He, N2O, SiH4 gases. The deposition is followed by a set of RTP anneals at different temperatures. After aluminium metallization and gate definition, C(V)- and FN-characteristics are measured. Interface trap densities, oxide charge densities, breakdown fields and breakdown charges are determined.