Integration of UHV-grown ferroelectric films into nonvolatile memories

Experimental evidence collected and evaluated during the preliminary development of a FEMFET (ferroelectric memory FET) is presented. In addition to microstructural characterization and ferroelectric polarization measurements, capacitance-voltage (C-V) measurements of several BaMgF sub(4) films grown under various conditions (ultrahigh vacuum (UHV) vs. regular high vacuum) were performed. The C-V hysteresis loops of the UHV-grown films showed that not only can the semiconductor conductivity be modulated directly through polarization reversal in the fluoride film, but also the saturated memory window is virtually undiminished after 10 super(7) switching cycles. The initial steps used to develop the integration of the FEMFET into a certified 1- mu m CMOS VLSIC process and the results achieved to date are reported.