A system and method for achieving a silicon carbide to low-k dielectric etch selectivity ratio of greater than 1:1 using a chlorine containing gas and either hydrogen (H2) gas or nitrogen (N2) gas is described. The method is applied to a semiconductor substrate having a low-k dielectric layer and a silicon carbide layer. The chlorine containing gas is a gas mixture that includes either HCl, BCl3, Cl2, or any combination thereof. In one embodiment, the method provides for supplying an etchant gas comprising a chlorine containing gas and a hydrogen (H2) gas. The etchant gas is then energized to generate a plasma which then etches openings in the silicon carbide at a faster etch rate than the low-k dielectric etch rate. In an alternative embodiment, the etchant gas mixture comprises a chlorine containing gas and a nitrogen (N2) gas.