Yuko Yabe

A highly manufacturable low power and high speed HfSiO CMOS FET with dual poly-Si gate electrodes

For 90 nm node poly-Si gated MISFETs with HfSiO (1.8 nm) insulator, a nearly symmetrical set of Vths for NFET and PFET: (0.38 V and -0.46 V, respectively) have been realized for low power device operation. The key technology is the suppression of Vth instability in PFETs arising from oxidation of the poly-Si/HfSiO interface, combined with channel engineering for the PFET. Our poly-Si/HfSiO gate-stacked CMOSFETs realize low I/sub off/ (N/PFET: 4.8/3.6 pA//spl mu/m) and high I/sub on/ (N/PFET: 469/140 /spl mu/A//spl mu/m) at V/sub DD/=1.2 V. Further, for SRAM cell using this CMOS, normal operation has been achieved.

Highly scalable nonvolatile TiOx/TaSiOy solid-electrolyte crossbar switch integrated in local interconnect for low power reconfigurable logic

A fully logic-compatible, nonvolatile crossbar switch using a novel dual-layer TiOx/TaSiOy solid-electrolyte, “NanoBridge”, has been developed for the first time, which is scalable to 50 nm and beyond and keeps the extremely low ON-resistance of ≪100 Ω. A key breakthrough is the dual-layer solid-electrolyte, in which TiOx works as an oxygen absorber as well as a superior ionic conductor, thus improving the yield, ON/OFF resistance ratio (≫106) and cycling endurance (≫103). The highly scalable 4 × 4 crossbar switch composed of NanoBridge integrated in a local Cu interconnect of a standard CMOS is successfully configured without select transistors. The nonvolatile solid-electrolyte, crossbar switch is a promising switch element for low power and low cost reconfigurable logic.

A new approach for improving operating margin of unipolar ReRAM using local minimu m of reset voltage

We propose a new approach for improving the operating margin of Ta2O5/plasma oxidized TiO2 stacked unipolar ReRAM. It was found that the reset voltage (switching from low resistance state to high resistance state) can be minimized by using local minimum against the resistance of the low resistance state. In addition, weakening the plasma oxidation condition reduced the power consumption and the variation of reset voltage. Excellent operating margin and more than 105 switching cycle times was successfully demonstrated using the integrated device.

Reliable solid-electrolyte crossbar switch for programmable logic device

Solid-electrolyte crossbar switch (namely NanoBridge) with low programming current of 420µA and highly reliable ON state against pulsed-alternating current (AC) stress is demonstrated under practical operating conditions of a programmable logic device (PLD). The ON-state duration under a pulsed-AC stress is achieved >10 years at 150°C. The high reliability under AC originates from the fact that the stress induced by Cu+ ion migration at a negative bias is recovered by a positive bias. NanoBridge is applicable in a scaled-down, nonvolatile PLD for hp28 and beyond.

1.2nm HfSiON/SiON stacked gate insulators for 65nm-node MISFETs

Motofumi Saitoh, Nobuyuki Ikarashi, Heiji Watanabe, Shinji Fujieda, Hirohito Watanabe, Toshiyuki Iwamoto, Ayuka Morioka, Takashi Ogura, Masayuki Terai, Koji Watanabe, Makoto Miyamura, Toru Tatsumi, Taeko Ikarashi, Koji Masuzaki, Yukishige Saito, Yuko Yabe System Devices Research Laboratories, NEC Corp., 1120 Shimokuzawa, Sagamihara, Japan Phone: +81-42-779-6193, FAX: +81-42-771-0886, E-mail:m-saitoh@ay.jp.nec.com