Scalable CMOS back-end-of-line-compatible AlScN/two-dimensional channel ferroelectric field-effect transistors

• Published in: Nature nanotechnology Vol. 18; no. 9; pp. 1044 - 1050
• Main Authors: Kim, Kwan-Ho, Oh, Seyong, Fiagbenu, Merrilyn Mercy Adzo, Zheng, Jeffrey, Musavigharavi, Pariasadat, Kumar, Pawan, Trainor, Nicholas, Aljarb, Areej, Wan, Yi, Kim, Hyong Min, Katti, Keshava, Song, Seunguk, Kim, Gwangwoo, Tang, Zichen, Fu, Jui-Han, Hakami, Mariam, Tung, Vincent, Redwing, Joan M., Stach, Eric A., Olsson, Roy H., Jariwala, Deep
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.09.2023; Nature Publishing Group
• Subjects: 639/166/987; 639/301/1005/1008; 639/301/357/1018; 639/925/357/1018; 639/925/927/1007; Arrays; Artificial intelligence; Chemistry and Materials Science; CMOS; Current density; Energy efficiency; Ferroelectric materials; Ferroelectricity; Field effect transistors; Low dimensional semiconductors; Materials Science; Memory devices; Molybdenum disulfide; Nanotechnology; Nanotechnology and Microengineering; Semiconductor devices; Transistors
• ISSN: 1748-3387; 1748-3395; 1748-3395
• DOI: 10.1038/s41565-023-01399-y

Three-dimensional monolithic integration of memory devices with logic transistors is a frontier challenge in computer hardware. This integration is essential for augmenting computational power concurrent with enhanced energy efficiency in big data applications such as artificial intelligence. Despite decades of efforts, there remains an urgent need for reliable, compact, fast, energy-efficient and scalable memory devices. Ferroelectric field-effect transistors (FE-FETs) are a promising candidate, but requisite scalability and performance in a back-end-of-line process have proven challenging. Here we present back-end-of-line-compatible FE-FETs using two-dimensional MoS 2 channels and AlScN ferroelectric materials, all grown via wafer-scalable processes. A large array of FE-FETs with memory windows larger than 7.8 V, ON/OFF ratios greater than 10 7 and ON-current density greater than 250 μA um –1 , all at ~80 nm channel length are demonstrated. The FE-FETs show stable retention up to 10 years by extension, and endurance greater than 10 4  cycles in addition to 4-bit pulse-programmable memory features, thereby opening a path towards the three-dimensional heterointegration of a two-dimensional semiconductor memory with silicon complementary metal–oxide–semiconductor logic. A large array of ferroelectric field-effect transistors with record memory windows, ON/OFF ratios and ON-current density is presented at ~80 nm channel length.