Solely Calcine Controlled Ferroelectricity and Resistivity of Barium Titanate Thin Films and Their Advanced Memory Applications

Thin films of barium titanate (BTO) are controllably grown to produce two different memory applications: ferroelectric Schottky diodes and resistive switching cells. The entire structure and fabrication of the two cells are identical, except for a slight adjustment to the calcination temperature for the BTO films. Films calcined at 800°C were ferroelectric and were used to create the ferroelectric Schottky diode. Conversely, films calcined at 700°C displayed resistive switching behavior and were used to create memristor cells. The ferroelectric Schottky diodes showed an ON/OFF ratio of over three orders of magnitude and the resistive switching cells showed an ON/OFF ratio of nearly two orders of magnitude, though both can likely be improved through electrode optimization. The identification of the critical process parameter shows that both memory cells can be fabricated on the same die with nearly identical processes, which would reduce process complexity for creating multiple advanced memories on a single die.