Kiyoshi Irino

Low standby power CMOS with HfO/sub 2/ gate oxide for 100-nm generation

We have fabricated 55-nm poly-Si gated n- and p-MOSFETs with HfO/sub 2/ gate dielectric of 3-nm physical thickness deposited by atomic layer deposition (ALD). A conventional CMOS process was used with high-temperature S/D anneal of /spl ges/1000/spl deg/C, cobalt-silicide and pocket implants. The devices showed very promising characteristics for low standby power applications due to drastic reduction of gate leakage current.

Ultra-thin (T eff inv = 1.7 nm) poly-Si-gated SiN/HfO 2 /SiON high-k stack dielectrics with high thermal stability (1050/spl deg/C)

Demonstrated the high-performance and high-reliability of ultra-thin poly-Si-gated SiN/HfO/sub 2//SiON high-k stack dielectrics. A SiN layer deposited on HfO/sub 2/ is shown to be indispensable to the suppression of the reaction of poly-Si and HfO/sub 2/, resulting in high thermal stability (1050/spl deg/C). This thermally stable SiN/HfO/sub 2//SiON structure can achieve an ultrathin oxide thickness of T/sub eff//sup inv/ (effective oxide thickness measured in strong inversion region) for 1.7 nm, which is less than 1 nm for EOT. A low leakage current of 5 to 6 orders of magnitude lower than that of SiO/sub 2/ was observed. In addition, this thermal stability can lead to high reliability, which includes TDDB and hot electron integrity.

High performance and highly reliable deep submicron CMOSFETs using nitrided-oxide

High performance and highly reliable CMOSFETs have been obtained using newly-developed nitrided-oxide processing, which features the localization of the nitrogen profile at the SiO/sub 2/-Si interface, and giving different nitrogen concentrations between the gate and LDD area. In p-MOSFETs, I/sub on/ can be increased by 12%, and I/sub off/ can be decreased by 50% compared with pure oxide. Also, in n-MOSFETs, hot carrier reliability significantly improves.

Impact of Nitrogen Profile in Gate Oxynitride on Complementary Metal Oxide Semiconductor Characteristics

We demonstrated that the control of the nitrogen profile in the gate oxynitride for complementary metal oxide semiconductors (CMOSs) is very important. We grew NO or N2O nitrided gate oxide at 800°C or 900°C to prepare three kinds of oxynitrides with different nitrogen profiles, and investigated the atomic configuration and the chemical state of nitrogen using secondary ion mass spectroscopy and X-ray photoelectron spectroscopy. Furthermore, we fabricated CMOS field effect transistors with gate oxide and oxynitride, and evaluated the interface state density and the hot carrier immunity. By systematical investigation of the relationship between the nitrogen profile and the electrical characteristics, we found that the nitrogen in the oxynitride should exist only at the interface for realizing the CMOS devices having high performance and high reliability.

Effects of interface oxide layer on HfO 2 gate dielectrics [MISFETS]

We report on the nMISFETs (n-type metal-insulator-semiconductor field effect transistors) characteristics for the atomic layer chemical vapor deposition (ALCVD) HfO/sub 2/ gate stack and the behavior of the HfO/sub 2/ layer during annealing on various oxides.