Interconnect structures comprising capping layers with low dielectric constants and good oxygen barrier properties and methods of making the same are provided. In one embodiment, the integrated circuit structure comprises: an interlevel dielectric layer disposed above a semiconductor substrate; a conductive interconnect embedded in the interlevel dielectric layer; a first capping layer comprising SiwCxNyHz disposed upon the conductive interconnect; a second capping layer comprising SiaCbNcHd (has less N) having a dielectric constant less than about 4 disposed upon the first capping layer; and a third capping layer comprising SiwCxNyHz disposed upon the second capping layer, wherein a+b+c+d=1.0 and a, b, c, and d are each greater than 0 and less than 1, and wherein w+x+y+z=1.0 and w, x, y, and z are each greater than 0 and less than 1.