| AVS 54th International Symposium | |
| Plasma Science and Technology | Thursday Sessions |
| Session PS2-ThM |
| Session: | Plasma Diagnostics I |
| Presenter: | M. Reinicke, Dresden University of Technology, Germany |
| Authors: | M. Reinicke, Dresden University of Technology, Germany S. Wege, Qimonda Dresden, Germany S. Barth, Qimonda Dresden, Germany A. Steinbach, Qimonda Dresden, Germany G. Wenig, Qimonda Munich, Germany A. Kersch, Qimonda Munich, Germany J.W. Bartha, Dresden University of Technology, Germany |
| Correspondent: | Click to Email |
Facing critical dimensions below 50nm requires significantly improved knowledge about complex process mechanisms for DRAM technology development. To extend the knowledge of physical and chemical interactions during high aspect ratio (HAR) silicon etching using HBr/NF3/O2 plasmas, in situ plasma analysis has been performed at the latest generation of multi frequency capacitively coupled MERIE plasma reactors. Focus of this presentation is a detailed investigation of ion angular and energy distribution functions (IAEDFs) since these distributions are considered to be most essential for characterization of plasma-induced silicon deep trench etching using reactive plasma chemistries. Ion distribution functions (IDFs) were measured for basic Ar, HBr, NF3, as well as complex HBr/NF3/O2 plasma chemistries at the ground electrode of the plasma reactor using an in situ Hiden Analytical EQP500 combined energy and mass analyzer. Measured IDFs are compared to calculations using the Hybrid Plasma Sheath Model (HPSM) simulator. Difficulties in measuring IDFs are minimized by simulation of ion trajectories and a careful determination of the relevant transmission functions specific for the plasma monitor used. The hybrid-fluid simulator was additionally modified by implementation of differential cross sections resulting from ab-initio calculations for relevant ion-atom collisions. Finally, combination of measurement and simulation for investigation of the complex nature of multi frequency high voltage rf plasma boundary sheaths is shown to yield valuable information on the IAEDF for ions impacting the substrate and hence influencing etch process results.