Selected topics on HfO/sub 2/ gate dielectrics for future ULSI CMOS devices

Based on our recent investigation on HfO/sub 2/ high-k gate dielectrics, we review the Hf based gate dielectric in the future ULSI CMOS devices in the following aspects: How long HfO/sub 2/ can be used satisfactorily, assessed from the gate tunneling and scalability; how thin EOT can be grown technologically assessed by interfacial layer thickness; and how high operating voltage can be employed for 10 years reliable operation, assessed by charge trapping and threshold voltage shift.