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.