ION-ASSISTED ETCHING OF BORON-NITRIDE IN RADIO-FREQUENCY CAPACITIVE DISCHARGES

Thin films composed of a mixture of hexagonal and cubic boron nitride (h-BN/c-BN) were treated by Ar, Ar/H-2 and Ar/Cl-2 plasma in a radio f requency (RF) capacitively coupled discharge. The c-BN concentration i n the film, as measured by Fourier transformed infrared spectroscopy ( FTIR), was increased by post-treatment under the described conditions. The Ar plasma used to identify the ion bombardment effect resulted in a slight increase in c-BN concentration. Ar/H-2 and Ar/Cl-2 treatment s were more efficient in increasing the c-BN concentration and illustr ated chemical effects and ion-assisted preferential etching of the h-B N by atomic hydrogen and Cl ions. These preliminary results are discus sed in view of a new deposition route for stress-reduced c-BN. (C) 199 8 Elsevier Science S.A.