Methods of forming silicon carbide coated base substrates at multiple temperatures

A method, comprising:

• flowing a first silicon-containing precursor to a process chamber at a first temperature of 1,000° C. to 1,400° C.;
• during flowing of the first silicon-containing precursor, decreasing the first temperature to a second temperature of 800° C. to less than 1,000° C. to form an amorphous first silicon carbide layer on a base substrate;
• and
• flowing a second silicon-containing precursor, that is the same as or different than the first silicon-containing precursor, to the process chamber at a third temperature, that is the same as or different than the first temperature, of 1,000° C. to 1,400° C. to form a polycrystalline second silicon carbide layer on the amorphous first silicon carbide layer.

A method, comprising:

• flowing a first silicon-containing precursor to a process chamber at a first temperature;
• during flowing of the first silicon-containing precursor, decreasing the first temperature to a second temperature to form an amorphous first silicon carbide layer on a base substrate;
• and
• flowing a second silicon-containing precursor, that is the same as or different than the first silicon-containing precursor, to the process chamber at a third temperature, that is the same as or different than the first temperature, to form a polycrystalline second silicon carbide layer on the amorphous first silicon carbide layer.