Patent ID: 7144824

Claim:
A method for controlling the properties of a dielectric anti-reflective coating (DARC) in a process of fabricating the DARC using a silicon-containing gas and oxygen as the reactive gases, the feature of the method comprising: adding a nitrogen-containing gas into the silicon-containing gas and the oxygen when forming the DARC, wherein the gas flow ratio of the nitrogen-containing gas to the silicon-containing gas and the oxygen—is about 0.01˜10 for controlling the n value of the DARC, and increasing the proportion of the silicon-containing gas to the oxygen or the proportion of the silicon-containing gas to the nitrogen-containing gas to control the k value of the DARC, wherein the gas flow ratio between the silicon-containing gas and the oxygen is about 1˜1.5 when the dielectric anti-reflective coating has an n value of about 1.7 and a k value of about 0.6.