Enhancement of the etch rate of LiNbO3 by prior bombardment with MeV O2+ ions

The implantation of LiNbO3 with 5 MeV O2+ ions has been examined as a means of increasing the rate of subsequent reactive ion etching in CF4/CHF3 plas mas. The etch rate of LiNbO3 implanted at a dose sufficient to amorphize th e substrate (1X10(15)-5X10(15) ions cm(-2)) was less than or equal to 3 tim es higher than in unimplanted substrates. The measured etch rates in CF4/CH F3, plasmas were essentially independent of the implant dose below 3X10(14) ions cm(-2) but increased significantly at and above 1X10(15) ions cm(-2). This transition was correlated with the onset of amorphization. In an Ar p lasma, the etch rate of LiNbO3, was unaffected by prior million electron vo lt implantation and was an order of magnitude lower than in the CF4/CHF3 pl asmas. These results have suggested that the damage induced by million elec tron volt implantation acted to accelerate the process of ion-enhanced chem ical etching in LiNbO3 but had no significant influence on the process of p hysical sputtering in an Ar plasma. (C) 1999 American Vacuum Society. [S073 4-2101(99)04306-7].