Low-Frequency Noise Characteristics of Ferroelectric Field-Effect Transistors

Low-frequency noise (LFN) characterization of ferroelectric field-effect transistor (FeFET) is performed. Two types of FeFET are compared, one with oxide-channel (W-doped, i.e, IWO) compatible back-end-of-line (BEOL) process, and the other with silicon-channel using front-end-of-line (FEOL) process. The LFN measurements are performed for ON and OFF memory state of the devices to study the effect of polarization on the noise performance. Furthermore, the normalized noise power spectral density (NNPSD) value is extracted, and the IWO FeFET shows lower value than the Si FeFET with a similar gate length. However, IWO FeFET has shown a higher NNPSD than IWO MOSFET. The LFN experimental data is an indicator of the interfacial trap density. We conclude that the BEOL process eliminates the interfacial layer and reduces the trap density, while the ferroelectric gate stack induces more carrier fluctuation than the dielectric gate stack due to the polarization effect.