A 9-Mb HZO-Based Embedded FeRAM With 10-Cycle Endurance and 5/7-ns Read/Write Using ECC-Assisted Data Refresh and Offset-Canceled Sense Amplifier<sup/>

Abstract

Hf0.5Zr0.5O2 (HZO)-based ferroelectric random access memory (FeRAM) is a good candidate for the embedded nonvolatile memory (eNVM) applications because of its high reliability, high speed, good scalability, and process compatibility with logic large-scale integrated circuits (LSIs). However, challenges still exist in designing robust read/write circuits for high reliability and sufficient read yield. This work presents a 9-Mb (8 + 1-Mb error correcting code (ECC)) HZO-based nonvolatile FeRAM chip with high-performance read and write peripheral circuits. A TiN/HZO/TiN ferroelectric capacitor (FeCAP) is integrated in the back-end-of-line of a 130-nm CMOS process with a 700-nm-diameter capacitor and a mega-level capacity. A temperature-aware ECC-assisted write driver (ECC-WD) is designed to improve the reliability and power efficiency of FeRAM. The offset-canceled sense amplifier (SA) and a dummy-based reference generator are designed to tolerate a small bitline (BL) signal margin and to reduce the read bit-error rate (BER). Measurement results show 2 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> remnant polarization ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{r}$ </tex-math></inline-formula> ) <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$&gt;$ </tex-math></inline-formula> 30 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{C}$ </tex-math></inline-formula> /cm2, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$&gt;$ </tex-math></inline-formula> 1012-cycle endurance, 7-ns write and 5-ns read time, sub-3-V operating voltage, and 10-year data retention at 85 °C.