Method of Etching a Composite Material Consisting of Electrically Conductive and Dielectric Particles
Original Publication Date: 1984-Nov-01
Included in the Prior Art Database: 2005-Feb-05
The difference in speed at which the two types of particles are etched is reduced by irradiation with highly energetic heavy ions. A typical material is N 58, an Al2O3/TiC (aluminium oxide/titanium carbide) ceramic composite. It is used in magnetic heads and preferably structured by reactive ion etching. As the etching of Al2O3 proceeds much more slowly than that of TiC, the surfaces obtained during etching are rough. By irradiation with heavy ions, such as Xe+, at energies of 5 to 20 MeV, the Al2O3, but not the TiC, is latently damaged. Heavy ions with energies exceeding a predetermined level interfere with electrical isolators but not with electric conductors. The irradiation process increases the etch rate of Al2O3 in a CF4 plasma.