Thermal Atomic Layer Deposition of Continuous and Highly Conducting Gold Thin Films

Five Au­(III) compounds were synthesized and evaluated for atomic layer deposition of Au thin films. One of the compounds, Me2Au­(S2CNEt2), showed optimal thermal characteristics while being volatile and thermally stable. In the growth experiments, this compound was applied with O3 at temperatures of 120–250 °C. Self-limiting growth was confirmed at 180 °C with a rate of 0.9 Å/cycle. The deposited Au thin films were uniform, polycrystalline, continuous, and conductive. Typical resistivity values of 40 nm thick films were 4–16 μΩ cm, which are low for chemically deposited thin films. The chemical composition of a Au thin film deposited at 180 °C was analyzed by time-of-flight elastic recoil detection analysis, proving the film was pure with small amounts of impurities. The detected impurities were O (2.9 atom %), H (0.9 atom %), C (0.2 atom %), and N (0.2 atom %).