METHOD FOR DEPOSITING COPPER ONTO BARRIER LAYER

摘要

PURPOSE: A copper depositing method is provided to absolutely capsulate a copper film on a barrier layer by using an electroless copper plating. CONSTITUTION: An electroless plating bath having a pH of at least 12.89 is used for allowing a copper(5) to adhere onto a barrier layer(3) such as tungsten at an adhesion speed of 50 nm/minute or less. By using the method, a trench(4) or via having an aspect ratio larger than 3 to 1 can become copper wiring with improved coherency.