Samsung Advanced Institute of Technology

In this study, we propose a CMOS-compatible exhalative annealing (EA) method that can significantly reduce the annealing temperature of Zr-doped hafnia-based ferroelectrics (HZO). Compared to the conventional rapid thermal annealing (RTA) process, our EA process reduces the crystallization temperature (T_cryst) of HZO films across all thickness ranges (5？10 nm). In particular, a 5 nm-thick HZO film, which is ideal for future 3D semiconductor devices, exhibited a 50% reduction in T_cryst from 500 ℃ to 250 ℃. X-ray photoelectron spectroscopy (XPS) analysis reveals that the EA method reduces both residual carbon and oxygen vacancy concentrations. HRTEM confirmed a significant reduction in interfacial mixing between HZO and the electrodes. Capacitors made of Mo-7nm HZO-Mo annealed using EA at 250 ℃ exhibited 2 orders of magnitude reduced leakage current at 3 MV/cm, along with robust ferroelectric properties (2Pr and 2Ec values of 36.7 ？C cm-2 and 2.38 MV cm-1, respectively). Implementing our method to ferroelectric field effect transistors (FeFETs) on a wafer scale resulted in a 33% increase in their memory window. The CMOS-compatible EA method is effective for producing ferroelectric field-effect transistors on a wafer scale and is well suited for the fabrication of next-generation hafnia-based ferroelectric nonvolatile memory. EA holds great promise for developing future semiconductor devices due to its industry-friendly process and minimal thermal damage.