Kim Dongsu, Jeong Heejae, Pyo Goeun, Heo Su Jin, Baik Seunghun, Kim Seonhyoung, Choi Hong Soo, Kwon Hyuk-Jun, Jang Jae Eun
Department of Electrical Engineering and Computer Science, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu, 42988, South Korea.
Department of Engineering, Institute for Manufacturing, University of Cambridge, Cambridge, CB3 0FS, United Kingdom.
Adv Sci (Weinh). 2024 Jul;11(28):e2401250. doi: 10.1002/advs.202401250. Epub 2024 May 13.
Ferroelectric field-effect transistors (FeFETs) are increasingly important for in-memory computing and monolithic 3D (M3D) integration in system-on-chip (SoC) applications. However, the high-temperature processing required by most ferroelectric memories can lead to thermal damage to the underlying device layers, which poses significant physical limitations for 3D integration processes. To solve this problem, the study proposes using a nanosecond pulsed laser for selective annealing of hafnia-based FeFETs, enabling precise control of heat penetration depth within thin films. Sufficient thermal energy is delivered to the IGZO oxide channel and HZO ferroelectric gate oxide without causing thermal damage to the bottom layer, which has a low transition temperature (<250 °C). Using optimized laser conditions, a fast response time (<1 µs) and excellent stability (cycle > 10, retention > 10 s) are achieved in the ferroelectric HZO film. The resulting FeFET exhibited a wide memory window (>1.7 V) with a high on/off ratio (>10). In addition, moderate ferroelectric properties (2·P of 14.7 µC cm) and pattern recognition rate-based linearity (potentiation: 1.13, depression: 1.6) are obtained. These results demonstrate compatibility in HZO FeFETs by specific laser annealing control and thin-film layer design for various structures (3D integrated, flexible) with neuromorphic applications.
铁电场效应晶体管(FeFET)对于片上系统(SoC)应用中的内存计算和单片3D(M3D)集成越来越重要。然而,大多数铁电存储器所需的高温处理可能会对底层器件层造成热损伤,这对3D集成工艺构成了重大物理限制。为了解决这个问题,该研究提出使用纳秒脉冲激光对基于氧化铪的FeFET进行选择性退火,从而能够精确控制薄膜内的热穿透深度。足够的热能被传递到铟镓锌氧化物(IGZO)氧化物沟道和氢化锆(HZO)铁电栅氧化物,而不会对具有低转变温度(<250°C)的底层造成热损伤。使用优化的激光条件,在铁电HZO薄膜中实现了快速响应时间(<1微秒)和出色的稳定性(循环次数>10次,保持时间>10秒)。由此产生的FeFET表现出宽的存储窗口(>1.7伏)和高的开/关比(>10)。此外,还获得了适度的铁电性能(剩余极化强度2·P为14.7微库仑/平方厘米)和基于模式识别率的线性度(增强:1.13,抑制:1.6)。这些结果通过特定的激光退火控制和针对各种具有神经形态应用的结构(3D集成、柔性)的薄膜层设计,证明了HZO FeFET的兼容性。