Charge Boosting Effect with Polarization Switching Properties of Zr Doped HfO₂ based Ferroelectric Capacitors for DRAM Cell Capacitor Application

As the 4^th industry accelerates, there are continuous requirements to enhance the density and performance of DRAMs. Efforts to increase integration density and improve the performance of DRAM have continued, but the development of a new concept of cell-cap due to the limitation of scaling down of Cell-CAP EOT is necessary. In recent studies, the possibility of increasing the amount of storage charge using the negative capacitance (NC) effect of ferroelectrics has been suggested to overcome this issue. However, a direct association between charge boosting and the ferroelectric characteristics such as domain switching distribution at the coercive field (Vc), and remanent polarization (Pr) has not been proved. Therefore, in this study, we analyzed the correlation of charge boosting according to ferroelectric properties in a cap for DRAM (TiN/Hf0.5Zr0.5O2/TiN) of less than 10nm. The dependence of the switching slope at Vc and storage charge amplification on Pr was confirmed. In this study, we show the charge boosting according to the device characteristics and propose conditions to maximize them.