Process and equipment simulation of dry silicon etching in the absence of ion bombardment

The dependence of the etch rate uniformity across the wafer on the reactor design and various process parameters was investigated for the reactive ion etching (RIE) of silicon using pure sulphur hexafluoride (SF6). The experi ments were carried out in two different single wafer reactors without ion b ombardment to determine the chemical component of the etch rate. The influe nce of pressure, gas flow, rf power, and loading on the radial course of th e etch rate was measured and compared with the respective results of numeri cal simulation. The commercially available PHOENICS-CVD simulation tool was used for the solution of the fluid dynamic transport equations after some adaptations for its application to etching. A simple chemical model is prop osed for the description of gas phase and surface plasma reactions, respect ively. The values of the reaction rate parameters were fitted from the expe rimental data. The simulation represents the main experimental trends and c an be applied to process and equipment optimization. (C) 1999 Elsevier Scie nce BN. All rights reserved.