An in-situ time-resolved infrared spectroscopic study of silicon dioxide (SiO/sub 2/) surface during selective etching over silicon in fluorocarbon plasma

Fluorocarbon (CF) film formation during SiO/sub 2/ plasma etching plays an important role in determining etch performance, in such areas as rate and selectivity. To understand the etching mechanism in the presence of CF film, we must know how the surface evolves from the very beginning of the etching process and how it reaches a steady-state at a specific thickness. To study these questions, a reactor with in-situ time-resolved infrared spectroscopy was designed that has a high optical throughput, shortened acquisition time and a precise sample-temperature control. In this paper, we study a series of spectra observed during etching. We focus mainly on the beginning process and discuss the rudimentary surface reaction.