An integrated circuit device includes a ferroelectric layer that is formed with chlorine-free precursors. A ferroelectric layer formed according to the present teaching may be chlorine-free. Structures adjacent the ferroelectric layer are also formed with chlorine-free precursors. The absence of chlorine in the adjacent structures prevents diffusion of chlorine into the ferroelectric layer and prevents the formation of chlorine complexes at interfaces with the ferroelectric layer. The ferroelectric layer may be used in a memory device such as a ferroelectric field effect transistor (FeFET). The absence of chlorine ameliorates time-dependent dielectric breakdown (TDDB) and Bias Temperature Instability (BTI).