We have fabricated stacked-gate structures with (i) thin Si-SiO2 heterostructures formed by a combination plasma-assisted and rapid thermal processing, and (ii) polysilicon gate electrodes deposited by rapid thermal chemical-vapor deposition (RTCVD). All processing was performed in situ and sequentially in a single chamber reactor, which provided for independent control of the interface formation and oxide deposition steps. The predeposition, low-temperature, 300-degrees-C, remote-plasma-assisted Si-cleaning/passivation/oxidation (i) removed residual C-atom contamination, (ii) created a device-quality Si-SiO2 interface, and (iii) generated approximately 0.5-0.6 nm of oxide, which served as a platform for die subsequent SiO2 deposition. Deposition of the SiO2 film, approximately 10.0 nm thick, was performed in situ by an 800-degrees-C RTCVD process. This study emphasizes the interface formation process, and its effect on electrical properties of stacked-gate structures in metal-oxide-semiconductor capacitors and field effect transistors.