Thermal oxide etch technique

A process is provided for etching thermally grown oxide. The process involves various steps and specific etch processing parameters used within a parallel electrode reactor. There are pre-stabilizing steps, followed by an etch step, which is then followed by post-stabilizing steps. The post-stabilizing steps may further include a particle removal or byproduct flush step in addition to the post-stabilizing steps. The process parameters are chosen to remove thermal oxide within contact regions at a uniform rate. The resulting thermal oxide is substantially uniform with less than 3.0% variance in thickness across the contact regions and across like areas of the entire wafer surface. The unique combination of pre-stabilize, etch, post-stabilize steps and process parameters chosen for each step thereby provides an improved etch uniformity of thermal oxide films within fine-line areas.