FLUORINATED AMORPHOUS-CARBON THIN-FILMS GROWN BY HELICON PLASMA-ENHANCED CHEMICAL-VAPOR-DEPOSITION FOR LOW DIELECTRIC-CONSTANT INTERLAYER DIELECTRICS

Fluorinated amorphous carbon thin films (a-C:F) for interlayer dielect rics are grown by helicon plasma enhanced chemical vapor deposition. T he source gases are CH4, CF4, C2F6 and their H-2-mixtures. a-C:F films can be fabricated without adding hydrogen using the helicon reactor, while in the previously reported parallel-plate reactor, no film grows unless a hydrogen source is added. The films grown in the helicon rea ctor have no hydrogen content. The growth rate of the films reaches 0. 3 mu m/min (C2F6) and 0.15 mu m/min (CF4). The thickness of the films deposited with C2F6 does not decrease on heating to 300 degrees C, whi le the films with CF4 shrink, The dielectric constants of the films de posited from C2F6 and CF4 are 2.4 and 2.3 respectively at 1 MHz. The d ielectric loss tangent of these films is 0.01 at 1 MHz. (C) 1996 Ameri can Institute of Physics.