dielectric films have been synthesized by remote plasma enhanced chemical vapor deposition ͑RPECVD͒ and deposited on ͑i͒ H-terminated Si͑100͒ and ͑ii͒ on SiO 2 prepared by remote plasma assisted oxidation and RPECVD on Si͑100͒ substrates using organometallic source gases injected downstream from a He/O 2 plasma. Chemical composition and morphology of the Al 2 O 3 films and their interfaces have been studied by Auger electron spectroscopy ͑AES͒, Fourier transform infrared spectroscopy, nuclear resonance profiling ͑NRP͒, and x-ray diffraction ͑XRD͒. Previous studies in which Al 2 O 3 was deposited by thermal CVD, rapid thermal CVD, ͑RTCVD͒, direct PECVD, and physical vapor deposition generally resulted in relatively thick SiO 2 or Al-silicate interfacial layers which impact adversely on the highest attainable capacitance. In line AES and NRP indicate the as-deposited RPECVD films are fully oxidized on deposition, and their interfaces can be chemically abrupt with Si oxide or Al silicate interfacial layers that are no more than 0.6 to 0.8 nm thick. However, these relatively abrupt interfaces do not ensure good device performance. Electrical measurements indicate negative fixed charge on the order of 10 12 charges/cm 2 . The fixed charge resides at the Al 2 O 3 interface, and can be moved away from the silicon substrate by deposition of a thin, ϳ1-2 nm, intermediate layer of RPECVD SiO 2 .

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