A SrRuO3/IrO2 top electrode FeRAM with Cu BEOL process for embedded memory of 130nm generation and beyond

Autor: Kazuhiro Tomioka, Yoshiro Shimojo, Tadashi Miyakawa, Koji Yamakawa, Daisaburo Takashima, Yoshinori Kumura, Yuki Yamada, S. Ohtsuki, O. Hidaka, Hiroyuki Kanaya, Iwao Kunishima, Shinichiro Shiratake, Akihiro Nitayama, Susumu Shuto, T. Ozaki, S. Yamazaki
Rok vydání: 2006
Předmět:
Zdroj: Solid-State Electronics. 50:606-612
ISSN: 0038-1101
DOI: 10.1016/j.sse.2006.03.015
Popis: A damage-robust SrRuO 3 /IrO 2 top electrode FeRAM with Cu BEOL process is demonstrated for the first time as a promising device for 130 nm CMOS embedded non-volatile memory. The ferroelectric capacitor with SrRuO 3 /IrO 2 top electrode has no degradation during Cu metallization to suppress oxygen and lead vacancies at a top electrode interface. Switching charge ( Q sw ) of 40 μC/cm 2 is achieved for 0.45 × 0.45 μm 2 top electrode (TE) size capacitor. Ninety percent saturation of Q sw is obtained at 1.1 V that is low enough to drive ferroelectric capacitors at 1.8 V for 130 nm CMOS. Opposite state polarization margin more than 90% is retained against imprint after the high temperature storage at 150 °C for 70 h. The combination of this high reliable capacitor with large Q sw and Chain FeRAM™ architecture with a small bit line capacitance [Ozaki T, Iba J, Yamada Y, Kanaya H, Morimoto T, Hidaka O, et al. In: Symposium on VLSI technologies technical digest; 2001. p. 113] drastically increases signal window for 1T1 C operation. A sharp signal distribution and a large peak-to-peak signal window of 730 mV at 1.8 V on the test device with 0.20 μm 2 area capacitors using three-level Cu metallization on 32 Mb Chain FeRAM™ are obtained. This technology realizes reliable embedded FeRAM of 130 nm generation and beyond.
Databáze: OpenAIRE
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