A STUDY ON INTERFACE AND CHARGE TRAPPING PROPERTIES OF NITRIDED N-CHANNEL METAL-OXIDE-SEMICONDUCTOR FIELD-EFFECT TRANSISTORS BY BACKSURFACEARGON BOMBARDMENT

A low-energy (550 eV) argon-ion beam was used to directly bombard the backsurface of nitrided n-channel metal-oxide-semiconductor field-effe ct transistors (n-MOSFETs) after the completion of all conventional pr ocessing steps. The interface and oxide-charge trapping characteristic s of the bombarded MOSFETs were investigated as compared to nonbombard ed and reoxidized-nitrided n-MOSFETs. It was found that after bombardm ent, interface state density decreases and interface hardness against hot-carrier bombardment enhances, and oxide charge trapping properties were also improved. The improvements exhibit a turnaround behavior de pending on bombardment conditions and could be attributed to stress co mpensation in the vicinity of the Si/SiO2 interface and an annealing e ffect. (C) 1997 American Institute of Physics.