Methods of forming semiconductor layer stacks comprising at least a portion of a vertical channel transistor structure

A method of epitaxially depositing a semiconductor layer stack comprising at least a portion of a vertical channel transistor structure, the method comprising:

• seating a silicon substrate in a reaction chamber;
• epitaxially depositing a doped silicon layer on the silicon substrate;
• epitaxially depositing a carbon doped silicon layer directly on the doped silicon layer;
• and
• epitaxially depositing a silicon channel layer directly on the carbon doped silicon layer,
• wherein the semiconductor layer stack is deposited by an isothermal chemical vapor deposition process without breaking vacuum within the reaction chamber.

A method of forming a semiconductor layer stack comprising at least a portion of a vertical channel transistor structure, the method comprising:

• seating a silicon substrate in a reaction chamber;
• heating the silicon substrate to a deposition temperature selected between 500 ° C. and 850 ° C.;
• epitaxially depositing the semiconductor layer stack by an isothermal chemical vapor deposition process comprising:
• introducing at least a first silicon precursor and a dopant gas into the reaction chamber to epitaxially deposit a doped silicon layer on the silicon substrate;
• introducing at least a second silicon precursor and a carbon dopant gas into the reaction chamber to epitaxially deposit a carbon doped silicon layer directly on the doped silicon layer;
• and
• introducing at least a third silicon precursor into the reaction chamber to epitaxially deposit a silicon channel layer directly on the carbon doped silicon layer,
• wherein the carbon doped silicon layer forms a blocking layer that reduces the migration of dopant species from the doped silicon layer into silicon channel layer.