• Conformal;
  • Hot filament CVD;
  • iCVD;
  • Polymer;
  • Step coverage


Initiated (i)CVD is used to deposit thin films of poly(cyclohexylmethacrylate) (pCHMA) in microtrenches of depth 7 µm and widths 1-5 µm. By changing the fractional saturation of the monomer vapor, step coverage of 0.85 is achieved for the highest aspect ratio trench studied while maintaining a deposition rate of 15 nm min−1. An analytical model for determining the sticking probability of the initiating radical (CH3)3CO· is developed, and is experimentally shown to be a function of the fractional saturation of the monomer vapor. For the conditions studied, the sticking probability is in the range 1.1 × 10−2–5.0 × 10−2. These results suggest that iCVD proceeds via the reaction of a vapor-phase initiating radical with a surface-adsorbed monomer.