Seeding of polymer substrates for nanocrystalline diamond film growth

Nanocrystalline diamond (NCD) thin films and structures are grown by microwave plasma CVD technique on SiO₂/Si substrates patterned by polymer. The substrates are seeded by ultra-dispersed diamond (UDD) nanoparticles in polymer, by spin coating of UDD drop and by ultrasonic treatment in solution of UDD.For all samples, the deposited NCD film is strongly related to the primary polymer deposited over the Si/SiO₂ substrate. For a certain concentration of UDD, seeding by polymer composite results in formation of fully closed layer. The drop of UDD requires using of spin coating process and by repeating of this procedure, a NCD layer with clear 3D geometry is achieved. Ultrasonic treatment leads in “implanting” of UDD into the polymer bulk. The primary polymer stripes are damaged during this procedure. In addition, 3D porous like layer is observed after the CVD growth.Optimizing the seeding procedure and the dimension of the primary polymer allow a direct growth of self-standing air bridges suitable for MEMS/NEMS applications.