Combined experimental and theoretical investigation on SONOS pFLASH switch

Abstract In this paper, a new push–pull pFLASH switch is designed and fabricated based on a 110 nm eFLASH process, which includes two 2 T-pFLASH transistors and one signal transmission transistor. The pFLASH transistors are programmed and erased by band-to-band tunneling-induced hot electron and Fowler–Nordheim tunneling to realize its ‘on/off’ function, and the current of the signal transmission transistor can be effectively tuned by the drain voltage of the 2 T-pFLASH. In order to clarify the degradation mechanism of the electronic properties, first principles calculations are performed from the atomic scale. Nitrogen vacancies have been proven to play a crucial role in nitrides. In addition, the effects of vacancies on the charge retention are investigated in terms of electronic structure. The nitrogen vacancies have proven to be detrimental to the electron storage by the simulated localization energies. Therefore, this study will provide a newly designed field-programmable gate array configuration unit, whose electrical mechanisms are revealed by theoretical simulations, which can also become the design foundation for future FLASH switches.