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A Study on the Temperature-Dependent Operation of Fluorite-Structure-Based Ferroelectric HfO2 Memory FeFET: A Temperature-Modulated Operation

: Ali, T.; Kühnel, K.; Czernohorsky, M.; Mart, C.; Rudolph, M.; Pätzold, B.; Lederer, M.; Olivo, R.; Lehninger, D.; Müller, F.; Hoffmann, R.; Metzger, J.; Binder, R.; Steinke, P.; Kämpfe, T.; Müller, J.; Seidel, K.; Eng, L.M.


IEEE transactions on electron devices 67 (2020), Nr.7, S.2793-2799
ISSN: 0018-9383
ISSN: 1557-9646
Fraunhofer IPMS ()

We report on the temperature-dependent operation of fluorite-structure-based ferroelectric FET (FeFET) emerging memory. A temperature range (-40 °C to 40 °C) is used to explore the FeFET characteristic relation to operating temperature. The memory window (MW) shows a modulated response that features a reciprocal MW dependence on temperature, such that a maximum of the MW is realized at -40 °C. The gradual MW closure upon temperature increase is attributed to the ferroelectric (FE) polarization change with temperature. On the contrary, the FE coercive field shows a minor variation with operating temperature. The FeFET state readout shows a trend of Vth shift with temperature such that the decrease in remnant polarization, as well as the substrate effects, causes a maximized shift for erase (ER) state compared to the program (PG) one. The benchmark of Si-doped hafnium oxide (HSO) and hafnium zirconium oxide (HZO) shows comparable trends for dependence on temperature. The temperature cycling by repetitive sweep from -40 °C to 40 °C shows reproducible MW and PG/ER readout trends with a predictable FeFET response over temperature. This suggests system design techniques for mitigating the variation effects. The FeFET characteristics are explored with insight on physical mechanisms and FE response to temperature variation.