In situ nucleation of diamond for thermal conductive applications

A method of forming film, the method comprising:

• exposing a substrate to a first plasma from a plasma source with a first plasma power in a range of from 10 W to 20,000 W, the first plasma comprising one or more of CxHy wherein y≥x, oxygen (O2), carbon dioxide (CO2), hydrogen (H2), nitrogen (N2), and argon (Ar) to provide a treated substrate;
• incubating the treated substrate with a gas stream and a second plasma to nucleate diamond particles on a top surface of the substrate, the gas stream comprising from 3% to 98% hydrocarbon and the second plasma having a power less than or equal to 15 kW;
• and
• exposing the diamond particles to a third plasma having a power greater than 50 W to form a microcrystalline diamond film on the top surface of the substrate, the microcrystalline diamond film having a grain size in a range of from 5 nm to 2 μm and a seed density in a range of from 105 per cm2 to 1011 per cm2.