Hysteresis-free negative capacitance in the multi-domain scenario for logic applications

Ferroelectrics (FEs) are known to decompose into multidomain structures when combined with dielectric (DE) layers. According to current understanding, it is thought that under such conditions, ferroelectric negative capacitance (NC) cannot be stabilized, and the operation of the device would be hysteretic. Here, we report, for the first time, that with a tight control of non-uniformity of the dielectric such that the capacitance matching conditions are nominally achieved, a hysteresis-free negative capacitance can be achieved in a multi-domain FE-DE structure. We capture the inhomogeneous switching in the FE layer by a novel circuit centric modeling framework that incorporates a distribution of domains with different ferroelectric and dielectric parameters. We observe that, in a FE-DE system with no intermediate, metallic layer, as high as ~95% of the ferroelectric domains in can be stabilized in the NC state which allows for the hysteresis free operation. We further show that when an intermediate metallic layer is introduced, the system does not exhibit stabilized NC behavior under any situation. The results could pave the way for understanding the design framework of robust, steep negative capacitance FETs (NCFETs) with multi-domain ferroelectrics.