Operating method of memory element

Abstract

The invention provides an operating method for a memory element. In the method, charges are stored into the source memory area, drain memory area and a channel memory area of charge storage layers above the source, drain and channel of a silicon oxide nitride oxide semiconductor (SONOS) transistor respectively, and thus, a single memory cell has the memory effect of a three-bit cell. The charges in the channel memory area are written and erased by means of Fowler-Nordheim (FN) tunneling; and the charges in the source memory area and the drain memory area are written by means of channel hot electron injection and erased by means of single-side FN tunneling. In the invention, a single memory cell can store three-bit cell data, so the memory density of the storage is improved greatly.

Description

technical field [0001] The invention relates to an operation method of a memory element, more specifically, the invention relates to an operation method of a memory element which enables a single transistor to have a multi-bit memory effect. Background technique [0002] The two-bit memory effect of general SONOS (silicon-oxide-nitride-oxide-silicon) memory is to use channel hot electrons and other writing methods to store electrons in the silicon nitride layer near the source or drain terminal, so that a single memory The source and drain of the cell can store information independently, achieving a two-bit effect. [0003] To achieve a memory effect of more than two bits, a multi-level cell (MLC) technology can be used to store different numbers of electrons on the floating gate, so that the memory has multiple start-up voltages. Then, the corresponding current is read by applying a read voltage between different starting voltages, so as to distinguish different memory sta...

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Problems solved by technology

[0004] However, these multi-bit memory methods need to have a sufficiently large initial voltage difference to avoid misjudgment of the memory state

In addition, the number of electrons injected into the floating gate must be quite accurate, so the detection is more complicated, and it causes problems of durability and durability

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