Impact of Series-Connected Ferroelectric Capacitor in HfO₂-Based Ferroelectric Field-Effect Transistors for Memory Application

• Published in: IEEE journal of the Electron Devices Society Vol. 8; pp. 1076 - 1081
• Main Authors: Liu, Wei-Dong, Huang, Zi-You, Ma, Jun, Zheng, Zhi-Wei, Cheng, Chun-Hu
• Format: Journal Article
• Language: English
• Published: New York IEEE 2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Capacitance; Capacitors; Current measurement; ferroelectric capacitor; Ferroelectric field-effect transistor (FeFET); Ferroelectric materials; Ferroelectricity; Field effect transistors; Hafnium compounds; Hafnium oxide; memory; Model matching; MOSFET; Semiconductor devices; TCAD simulation; Thickness; Transistors; Voltage measurement
• ISSN: 2168-6734; 2168-6734
• DOI: 10.1109/JEDS.2020.3029268

In this work, we demonstrated a HfO 2 -based ferroelectric field-effect transistor (FeFET) in series with a HfAlO ferroelectric capacitor for memory application and further investigated the impact of the ferroelectric capacitor with different thicknesses and areas. It was revealed that the memory window of the FeFET has a significant correlation with the ferroelectric capacitor from the transfer curves of the transistor after the series connection. By decreasing the thickness and area of the ferroelectric capacitor, the memory window of the FeFET was improved, which could be verified through the TCAD simulation tool and capacitance matching model. With the series-connected ferroelectric capacitor, in addition to optimizing the characteristics of ferroelectric memory, we can effectively avoid the interface-caused undesirable effects in conventional ferroelectric memory during film stacking. These results provide a solution for future low-power embedded memory application.