Plasma etching process induced poly film damage

The DRAM poly top plate pattern damage had been randomly observed right after reactive plasma poly etch in the production line. Plasma etching chamber condition's shift caused by the switch between different Cl-2/HBr gas ratio etch recipes had been verified to be the major culprit. The poly damage can be avoided by recipe grouping in different poly etchers. This case is a good example showing that the plasma etching chamber condition can be altered drastically by simply applying different etching recipes. However, the utilization of the expensive manufacturing tools and the recipe grouping again become the two opposite sides on the scale.