Experimental Investigation of Pulsed Laser Deposition of Ferroelectric Gd:HfO2 in a CMOS BEOL Compatible Process

In this work, we report an experimental investigation of pulsed laser deposition (PLD) of thin Gd:HfO2 layers at 330 degrees C, which show ferroelectric behavior after annealing at 450 degrees C, compatible with complementary metal-oxide-semiconductor back-end-of-line processing. The material's ferroelectricity is confirmed by microstructural and electrical analysis, corroborated by hysteretic electromechanical response measured via piezoresponse force microscopy. The effect of postdeposition annealing ambient is also studied, where N-2 annealing results in higher remanent polarization, while O-2 annealing yields greater endurance properties. Furthermore, ferroelectricity is demonstrated for PLD thin films formed on a conventional TiN/Si structure, demonstrating the strong potential of this PLD material for cointegration in relevant memory and logic applications.