Method for providing doped silicon using a diffusion barrier layer

A processing chamber, comprising:

• a processing station;
• a pedestal for supporting a substrate at the processing station;
• a showerhead for providing processing gas to the substrate at the processing station;
• a radiofrequency power system configured to form a plasma in the processing chamber;
• a gas source fluidly connected to the showerhead;
• a vacuum system;
• and
• a controller controllably connected to the gas source, the radio frequency power system, and the vacuum system, the controller configured to control the processing chamber to form a silicon oxide diffusion barrier layer on a surface of the substrate to be thicker over an outer edge of the substrate than over a center of the substrate;
• deposit at least one dopant layer over the silicon oxide diffusion barrier layer;
• deposit a cap layer over the at least one dopant layer forming a stack of the substrate, the silicon oxide diffusion barrier layer, the at least one dopant layer, and the cap layer;
• and
• anneal the stack.

A processing chamber, comprising:

• a processing station;
• a pedestal for supporting a substrate at the processing station;
• a showerhead for providing processing gas to the substrate at the processing station;
• a radiofrequency (RF) power system configured to form a plasma in the processing chamber;
• a gas source fluidly connected to the showerhead;
• a vacuum system;
• and
• a controller controllably connected to the gas source, the radio frequency power system, and the vacuum system, the controller configured to control the processing chamber to
• form a silicon oxide diffusion barrier layer on a surface of a substrate by an atomic layer deposition process comprising a plurality of cycles, each cycle comprising
• flowing a first reactant gas comprising a silicon containing precursor to deposit a silicon containing precursor layer on the substrate,
• stopping the flow of the first reactant gas,
• flowing a second reactant gas,
• providing an RF power to form a plasma comprising the second reactant gas,
• transforming the silicon containing precursor layer on the substrate to silicon oxide, and
• stopping the flow of the second reactant gas;
• deposit at least one dopant layer over the silicon oxide diffusion barrier layer;
• and
• deposit a cap layer over the at least one dopant layer to form a stack of the substrate, the silicon oxide diffusion barrier layer, the at least one dopant layer, and the cap layer.