Patent ID: 11915976
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 10:
11. A pre-clean tool, comprising:
one or more devices configured to:
provide, as part of a pre-clean process, ammonia gas and nitrogen fluoride gas into a processing chamber to cause an ammonium fluoride gas to form at a rate satisfying a threshold rate;
form, as part of the pre-clean process and based on the ammonium fluoride gas being formed at the rate, a protection layer above an insulating cap, a dielectric layer, and a source or drain region of a semiconductor device,
wherein the protection layer protects the source or drain region from being etched by fluorine ions during the pre-clean process, and
wherein the protection layer reacts with an oxide layer on the insulating cap, the dielectric layer, and the source or drain region to remove the oxide layer from the insulating cap, the dielectric layer, and the source or drain region; and

remove the protection layer after performing the pre-clean process.