A heater stuck includes first strata having a planar configuration supporting and forming a fluid heater element responsive to repetitive electrical activation and deactivation to produce repetitive cycles of fluid ejection from an ejection chamber above the heater element and second strata having a planar configuration coating the heater element of the first strata and being contiguous with the ejection chamber to protect the heater element. The first strata include a substrate and heater strata disposed on it and forming a cavity above the substrate and encompassed on three sides by the heater substrata. The heater substrata includes a pair of conductive layer portions constituting terminal leads disposed on the substrate at opposite sides of the cavity and a resistive layer disposed on the conductive layer portions and defining the fluid heater element that spans the top of the cavity.