| 摘要 |
A plasma etch process for etching a workpiece in a processing chamber of a plasma reactor which produces improved photoresist layer etch uniformity and selectivity, reduced faceting of the photoresist, reduced polymer peeling, and reduced etching of exposed barrier layer surfaces. This improvement is obtained by modifying certain process parameters in a way atypical of current etch processes. Specifically, the chamber pressure and/or flow rate of fluorine-containing components of the etchant gas are increased. In addition, a decrease in the source power used to maintain the plasma or an increase in the roof temperature of the chamber will also contribute to the improvement. To prevent the occurrence of significant etch stopping, a diluent is added to the etchant gas to limit the formation of polymer. The addition of a diluent works well up to a point, after which the combined effect of modifying the aforementioned process parameters causes etch stopping regardless of the amount of diluent gas flowing through the chamber. Therefore, values chosen for the four process parameters are coordinated to optimize the benefits of the present invention, while minimizing etch stopping. <IMAGE> |
