Flash memory device

Abstract

The invention discloses a flash memory device. Through only arranging a buried oxide layer below a drain end, the modulation function of a two-dimensional electric field is utilized so that an electric field next to the drain end is improved and electron hole collision probability is improved, thereby improving hot carrier generation probability, changing more electrons to hot electrons for being injected into a floating gate, and greatly improving device programming efficiency. Furthermore holes which are generated by impact ionization can be discharged through a silicon substrate next to the buried oxide layer, thereby preventing hole accumulation, thoroughly eliminating a floating body effect and realizing stable device programming efficiency. Furthermore because the flash memory device greatly improves the device programming efficiency, the programming voltage of the device can be reduced. The relatively low programming voltage reduces dynamic power consumption of a circuit. Furthermore an influence by a drain-end interference can be reduced.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a flash memory device. Background technique [0002] Flash memory (Flashmemory) is a new type of non-volatile semiconductor memory developed based on EPROM and EEPROM. It has the characteristics of cheap price, relatively simple process, and can be easily and quickly erased and written many times. It has been widely used, mainly in portable devices and embedded systems. [0003] Norflash relies on hot electron injection to store data, that is, electrons are accelerated in the channel by the transverse electric field at the drain and source, and hot electrons are formed near the drain. Through phonon scattering, under the action of the vertical electric field of the gate, some electrons It will be injected into the floating gate through the tunnel oxide layer, and the threshold voltage of the device will change accordingly, so as to achieve the purpose of stor...

AI Technical Summary

Problems solved by technology

[0008] In view of the above existing problems, the present invention discloses a flash memory device to overcome the structure of the prior art flash memory device, only a small part of electrons can be injected into the floating gate as hot electrons, and most of the electrons flow out through the drain terminal, thereby affecting The programming speed and programming efficiency of the device are problematic, and the use of SOI flash memory devices is prone to the problem of floating body effect

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