Apparatus and method to improve resist line roughness in semiconductor wafer processing

Abstract

A process for prohibiting amino group transport from the top surface of a layered semiconductor wafer to a photoresist layer introduces a thin film oxynitride over the silicon nitride layer using a high temperature step of nitrous oxide (N2O) plus oxygen (O2) at approximately 300° C. for about 50 to 120 seconds. By oxidizing the silicon nitride layer, the roughness resulting from the adverse affects of amino group transport eliminated. Moreover, this high temperature step, non-plasma process can be used with the more advanced 193 nanometer technology, and is not limited to the 248 nanometer technology. A second method for exposing the silicon nitride layer to an oxidizing ambient, prior to the application of antireflective coating, introduces a mixture of N2H2 and oxygen (O2) ash at a temperature greater than or equal to 250° C. for approximately six minutes. This is followed by an O2 plasma clean and/or an Ozone clean, and then the subsequent layering of the ARC and photoresist.

Dependencies are inferred from the claim text.