Method of high selectivity wet etching of salicides

摘要

A method for forming salicides with lower sheet resistance and increased sheet resistance uniformity over a semiconductor process wafer including providing a semiconductor process wafer having exposed silicon containing areas at a process surface; depositing a metal layer including at least one of cobalt and titanium over the process surface; carrying out at least one thermal annealing process to react the metal layer and silicon to form a metal silicide over the silicon containing areas; and, wet etching unsilicided areas of the metal layer with a wet etching solution including phosphoric acid (H3PO4), nitric acid (HNO3), and a carboxylic acid to leave salicides covering silicon containing areas at the process surface.