Abstract

 We demonstrate a charge-trap flash (CTF) device with a germanium-incorporated silicon nitride (Ge:SiN) charge-trap layer (CTL). Compared to a conventional SiN CTL, the 6 nm-thick Ge:SiN CTL exhibits increased trap density and deeper trap levels. As a result, the Ge:SiN device achieves a 34% larger memory window, along with enhanced retention and endurance characteristics. To further validate, we conducted a spatial study at 4 nm-thick CTL by varying the Ge-incorporated region within the CTL, examining both the tunneling oxide proximal (T_OX-proximal) Ge:SiN device and the blocking oxide proximal (B_OX-proximal) Ge:SiN device. The BOX-proximal Ge:SiN device consistently exhibits memory performance enhancement. These results provide guidelines for the spatial engineering of Ge:SiN CTL, confirming that the memory performance advantages of the Ge incorporation persist down to 4 nm and supporting a B_OX-proximal Ge incorporation. The material and spatial engineering demonstrate the potential of Ge:SiN CTL for next generation 3D NAND flash memory.