Memory cell of multi-value phase-change random access memory and operating method thereof

Abstract

The invention discloses a memory cell of a multi-value phase-change random access memory and an operating method thereof. According to the memory cell, by using the parasitic effect of a phase-change random access memory, during writing, the falling time of RESET voltage of a phase-change memory element is changed by changing the total parasitic resistance of a strobe element to ensure that a part of the phase-change memory element is crystallized and the amorphous resistance (RESET resistance) of the phase-change memory element is changed, and during reading, small current is input to sense the voltage on the phase-change memory element so as to read a numerical value memorized by the phase-change memory element, so that the multi-value memory by using one phase-change memory element is realized. Through the memory cell and the operating method, the multilevel memory can be realized by using one phase-change memory element, and a reading-writing circuit is not required to be changed, so that the memory density of a phase-change random access memory can be effectively improved in a large-scale memory.

Description

technical field [0001] The invention belongs to the technical field of semiconductor storage, and in particular relates to a storage unit of a multi-valued phase-change random access memory and an operation method thereof. Background technique [0002] Phase-change random access memory (PCRAM) is a non-volatile memory because it is compatible with silicon-based semiconductor processes, and it also has the high capacity and low cost of DRAM, the high speed of SRAM, and the data non-volatility of FLASH. , and also has excellent characteristics in terms of reliability and low power consumption, it has been recognized as the next-generation semiconductor storage device that is most likely to replace today's mainstream products such as SRAM, DRAM and FLASH and become the mainstream of future memory. [0003] Phase-change random access memory is a reversible structural phase change of the storage medium by passing a write current to generate Joule heat, and uses the resistance dif...

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Problems solved by technology

However, under this structure, the operating current can only be reduced by reducing the size of the phase-change memory element, thereby increasing the storage density, which requires extremely high requirements for the manufacturing process.

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