An Ultra-Dense One-Transistor Ternary-Content-Addressable Memory Array Based on Non-Volatile and Ambipolar Fin Field-Effect Transistors
Zhaohao Zhang, Shujuan Mao, Gaobo Xu, Qingzhu Zhang, Zhenhua Wu, Huaxiang Yin, Tianchun Ye
Abstract
An ultra-dense one-transistor (1T) ternary-content addressable memory (TCAM) array is reported that is based on high-performance, non-volatile, and ambipolar ferroelectric (Fe) silicon-on-insulator (SOI) fin field-effect transistors (FinFETs). Because of the multistates in the Fe layer and the ambipolar characteristics, TCAM functions were realized on a single device. From the advanced CMOS process and the metallic source and drain (MSD) engineering, a maximum driving ON-current of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 0.1~\mu \text{A}/\mu \text{m}$ </tex-math></inline-formula> and a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 1000$ </tex-math></inline-formula> ON/OFF ratio at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {GS}}= -0.25$ </tex-math></inline-formula> V were realized for the 1T TCAM cell. This indicated large-array integration feasibility. In addition, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${2} \times {2}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${1} \times {8}$ </tex-math></inline-formula> TCAM arrays are demonstrated. The quasi-linear dependence of a matching line (ML) voltage with the number of mismatched bits indicated a potential for Hamming-distance computing in area- and energy-efficient artificial intelligence (AI) processors.