THE ATOMIC LAYER DEPOSITION METHOD FOR FABRICATING ALUMINUM LAYER

摘要

PURPOSE: A method for forming an aluminum(Al) interconnection layer by an atomic layer deposition is provided to improve the uniformity and step coverage of the Al layer. CONSTITUTION: In the method, a semiconductor substrate is loaded into a deposition chamber. Next, an Al source gas is supplied into the deposition chamber and then chemisorbed onto the semiconductor substrate to form the Al layer. Next, a purge gas is supplied into the deposition chamber without supplying the Al source gas, so that non-reacted Al source gas staying in the deposition chamber is removed and thereby the Al layer is completed. Thereafter, to form the Al layer to a required thickness, the steps of supplying the Al source gas and supplying the purge gas are repeatedly performed. Thereby, a multilayered Al layer is formed, allowing improvement in uniformity and step coverage. Preferably, the supply step of the purge gas is followed by the step of removing impurities in the Al layer by supplying an Al layer reducing gas into the deposition chamber without supplying the purge gas, and the step of removing non-reacted reducing gas by supplying the purge gas without supplying the reducing gas.