The formation of Si-SiO2 interfaces for 40–60Å rapid thermal CVD (RTCVD) MOS gate oxides has been studied, using cluster tool technology. SiH4/N2O chemistry is used to deposit stoichiometric oxides. In-situ thermal treatments, prior to oxide deposition, typically at 800–900°C, 30–60 sec, and 50 Torr. are conducted using O2, N2O, SiH4, NH3, HCl/N2 and HCl/O2. The effect of gas flow ratios during temperature ramp-up for RTCVD interface formation is also studied. This paper presents a new quick-turnaround approach for non-destructive evaluation of Si-SiO2 interface quality for fully fabricated devices, in terms of interface charges and surface roughness.