Atomic layer deposition of ZrO2 using a novel high-temperature precursor, (nPrCp)Zr(NMe2)3

ZrO2 thin films were deposited by atomic layer deposition using a new, high-temperature tolerant Zr precursor (nPrCp)Zr(NMe2)3 ((C8H11)Zr[N(CH3)2]3) and ozone. The precursor exhibited minimal thermal decomposition at temperatures up to 380 °C, compared to the commonly used CpZr(NMe2)3 ((C5H5)Zr[N(CH3)2]3), which started to decompose above 305 °C. Films deposited using the new precursor at temperatures above 350 °C were more crystalline and contained less impurities than films deposited at lower temperatures. TiN/ZrO2/Al capacitors with ZrO2 films of various thicknesses deposited using (nPrCp)Zr(NMe2)3 at 365 °C had slightly lower equivalent oxide thickness values than similar capacitors with films deposited using CpZr(NMe2)3 at 305 °C. Leakage currents were also similar when the ZrO2 film thicknesses were about 6 nm, but a capacitor with a 4 nm thick film deposited using (nPrCp)Zr(NMe2)3 had a higher leakage current density than a capacitor with a 4 nm thick film deposited using CpZr(NMe2)3.