Fabrication and characteristics of P-channel silicon-oxide-nitride-oxide-silicon flash memory device based on bulk fin shaped field effect transistor structure

Abstract

A p-channel silicon-oxide-nitride-oxide-silicon (SONOS) flash memory device based on bulk fin shaped field effect transistor (FinFET) structure was fabricated and characterized as a highly scalable device structure. Key process steps were explained in detail and electrical characteristics were measured. The threshold voltage shift (ΔVth) was checked in the proposed device with the source/drain floating and grounded. This result means that the proposed device structure can be applicable to NAND and NOR flash memories. In this structure, program/erase times can be controlled by fin body width, which is the unique parameter of FinFET structure. In the endurance test, about 1.3V of the ΔVth was kept until 104P∕Ecycles. The ΔVth of the proposed flash memory device was extrapolated to about 0.5V after 10y retention. The ΔVth with crystal orientation of the side-channel also was checked.