Characterization in Silicon Processing

containing compound, most

typically

molecular hydrogen or silane. The source

gases

will

thermally decompose on heated surfaces (either the substrate or reactor

surface)

and react to form elemental tungsten and fluorinated byproducts

(SiF

4

and

H

2

for silane chemistry, HF for H

2

reduction reaction).

CVD of tungsten can be

done

in two modes: blanket and selective. The mode

is

primarily controlled by the substrate surface conditions, and the same deposition

chemistries

can be used for

both

modes. In addition, the reactant gas flows (partial

pressures),

reactor pressure, and temperature

will

determine the film properties of

the deposition and

wil ...