XPS studies of contamination of reactor and silicon surfaces caused by reactive ion etching
X-ray photoelectron spectroscopy measurements have been carried out to determine the contamination of reactor walls and of different SiO2/Si wafers after the reactive ion etching processes. Different cleaning processes have also been assessed by this method. The Al(2p) or Si(2p), C(1s), O(1s) and F(1s) photoelectron lines were monitored and concentrations determined by integration of these lines. F(1s) and C(1s) were decomposed into several components corresponding to different chemical bonds. The results show that contamination of the reactor walls by fluoropolymers is due to the presence of Si or the photoresist; there is no polymer formation with an Al cathode coating. The polymers are cleaned by O2 plasma and the residual fluorine forms a passive layer with the Al of the reactor walls.