Selective etch of a stack with a carbon containing mask

A method of etching recessed features in a stack below a carbon containing mask, wherein the carbon containing mask has a top surface, the method comprising a plurality of cycles, wherein each cycle comprises:

• a. a carbon deposition phase for selectively depositing carbon on the top surface of the carbon containing mask, comprising:
• i. activating the top surface of the carbon containing mask by bombarding the top surface of the carbon containing mask with ions;
• ii. flowing a deposition gas comprising a hydrogen source and an organochloride source selected from at least one of carbon tetrachloride (CCl4) and CxHyClz (where x>0 and z>0);
• and
• iii. forming the deposition gas into a plasma to form at least one of radicals and ions of CnClm (where x>0 and z>0) and at least one of radicals and ions of H, which deposit carbon on the carbon containing mask;
• and
• b. an etch phase that etches features into the stack.