Table of Contents
Laser Chemistry
Volume 5, Issue 1, Pages 35-52

Interaction of SF6 Multiple Photon Dissociation Products With Silicon and SiO2 Surfaces

Institute of Spectroscopy, USSR Academy of Sciences, Moscow Region, Troitzk 142092, Russia

Copyright © 1984 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Experiments on etching Si and SiO2 by the multiple photon dissociation products of SF6 molecule in IR laser field have been carried out. These experiments showed that the etching of Si and SiO2 is the result of two qualitatively different processes and high selectivity (>103) can be achieved. The dependences of the etching process of the initial gas mixture pressure and composition, on the laser intensity and the number of laser pulses and on the direction of laser radiation have been studied. It has been found out that the etching rates of “a monolayer per pulse” for Si and ~100 Å/min for SiO2 are comparable to the rates achieved in low-temperature plasma technique. Possible mechanisms and chemical reactions which can cause Si and SiO2 etching are discussed. It has been concluded that under the experimental conditions multiple photon dissociation forms the basis for the etching process.