Multi-layered epitaxial stack formed in a presence of a higher order silicon precursor

A processing chamber configured to:

• sequentially deposit a carbon-doped silicon germanium stack and a silicon film to form a carbon-doped silicon-germanium and silicon mini-stack disposed on a substrate during a deposition cycle, wherein the deposition cycle comprises:
• exposing a workpiece comprising the substrate to a first gas comprising a first precursor to deposit a first silicon-germanium layer;
• exposing the workpiece to a second gas comprising the first precursor to deposit a carbon-silicon-germanium layer on the first silicon-germanium layer;
• exposing the workpiece to a third gas comprising the first precursor to deposit a second silicon-germanium layer on the carbon-silicon-germanium layer;
• and
• exposing the workpiece to a fourth gas comprising a second precursor to deposit the silicon film on the second silicon-germanium layer, wherein the second precursor differs from the first precursor.

A workpiece, comprising:

• a multi-layered epitaxial stack disposed on a substrate, the multi-layered epitaxial stack comprising:
• a plurality of carbon-doped silicon-germanium stacks, wherein each of the plurality of carbon-doped silicon-germanium stacks is deposited in a presence of a first precursor;
• and
• a plurality of silicon films, wherein each of the plurality of silicon films is deposited on a respective one of the plurality of carbon-doped silicon-germanium stacks, wherein each of the plurality of silicon films is deposited in a presence of a second precursor, and wherein the second precursor differs from the first precursor.