Ultralow‐Consumption Ferroelectric‐Like Diamond Transistors for Advancing Logic Circuits

ABSTRACT The relentless upscaling of chip integration density keeps urging microelectronic engineering to minimize the power consumption of individual field‐effect transistors (FETs). However, due to the narrow bandgap and the relatively large dielectric constant of silicon, it has become nearly infeasible to further suppress the off‐current in silicon‐based FETs at advanced technology nodes. Moreover, the implementation of energy‐efficient FETs is also precluded by the thermionic limit of subthreshold swing (SS) defined by Boltzmann's tyranny. Here, we report on the development of ferroelectric‐like FETs through the integration of hydrogen‐terminated diamond surface with a ZrO 2 capping layer, which exhibit an ultralow off‐current (∼0.1 fA·µm −1 ), a record‐high on/off ratio (> 10 11 ), and a steep SS (6 mV·dec −1 ) sustained well below the Boltzmann limit for over five decades of the drain current. The ZrO 2 capping layer shows a pronounced ferroelectric‐like behavior with distinct polarization states. Based on structural analyses and positive‐up negative‐down (PUND) measurements, we speculate that the formation of dipolar polarization in the ZrO 2 layer is caused by the migration of oxygen vacancies, and the voltage‐driven dipolar polarization switching can amplify the channel surface potential, which in turn leads to the outstanding off‐state performance and the subthreshold current characteristics of the transistors. The FETs with great repeatability are employed to construct inverter circuits, which feature a high voltage gain exceeding 400 and significantly suppressed static power consumption. This study provides a promising pathway toward future low‐power integrated circuits.