| AVS 63rd International Symposium & Exhibition | |
| Plasma Science and Technology | Monday Sessions |
| Session PS-MoA |
| Session: | Advanced BEOL/Interconnect Etching |
| Presenter: | Andre Labonte, GLOBALFOUNDRIES |
| Authors: | A.P. Labonte, GLOBALFOUNDRIES A. Carr, IBM J.M. Dechene, GLOBALFOUNDRIES J.C. Shearer, IBM J.M. Lucas, Tokyo Electron America B. Messer, Tokyo Electron America A. Metz, Tokyo Electron America |
| Correspondent: | Click to Email |
As the semiconductor industry drives to sub 50nm gate and interconnect pitches, aspect ratios of contact and via structures are increasing. Subsequently, dielectric and etch stop layers are being thinned to mitigate the increase in aspect ratios. Likewise, the ongoing pursuit of scaling, without proportional changes in overlay, are driving the need for ever more selective Self-Aligned Contact (SAC) dry etch processes. As with any plasma, there is the potential to cause plasma damage to exposed surfaces and stop layers. The plasma damaged materials may in turn be susceptible to significant changes in their properties which may enhance or inhibit future removal of the stop layer. Finally, due to the thinner stop layers being used, this change of material properties in a plasma damaged layer may not be limited to the surface of the layer, but may in fact convert the entire film.
In this paper, we discuss an example where a dielectric system, etched with a SAC process, exhibited an unexpected change in the material properties of the underlying etch stop layer. Process partitioning and materials analysis were used to confirm the unexpected result and develop a theory for observed changes.