High-temperature implant for gate-all-around devices

A method for forming a gate-all-around (GAA) device, comprising:

• forming a nanowire stack comprising a plurality of alternating first layers and second layers and an outer gate spacer adjacent the plurality of alternating first layers and second layers;
• forming a source/drain (S/D) cavity by etching the plurality of alternating first layers and second layers, and by etching the outer gate spacer;
• forming an inner spacer in the S/D cavity, adjacent the plurality of alternating first layers and second layers;
• performing a first implant by directing fluorine ions to the inner spacer, through the S/D cavity, wherein the first implant is performed at a temperature greater than 500° Celsius;
• forming a S/D material in the S/D cavity following the first implant;
• and
• performing a second implant by directing fluorine ions to the outer gate spacer of the nanowire stack, wherein the second implant is performed before the S/D cavity is formed by etching the plurality of alternating first layers and second layers, and by etching the outer gate spacer.

A system, comprising:

• a processor;
• a memory storing instructions executable by the processor to:
• perform a first implant by directing fluorine ions into a gate-all-around (GAA) stack comprising a plurality of alternating first layers and second layers, wherein the fluorine ions are directed through a source/drain cavity formed adjacent the GAA stack, wherein the first implant is performed at a temperature greater than 500° C. Celsius, and wherein an outer gate spacer and an inner spacer are formed along the GAA stack before the fluorine ions are directed through the source/drain cavity;
• and
• perform a second implant by directing fluorine ions to the GAA stack, wherein the second implant is performed before the source/drain cavity is formed by etching the plurality of alternating first layers and second layers.