A kind of preparation method of flash memory

Abstract

The invention provides a method for preparing a flash memory. The invention performs oxidation treatment on a semiconductor substrate formed with a tunnel oxide layer before forming a floating gate, so as to enhance the stability of the surface of the active region in contact with the tunnel oxide layer. Simultaneously, the present invention reduces the deposition thickness of the metal layer that prepares metal silicide and carries out the heat treatment that will form metal silicide in two stages, helps to strengthen the stability and the surface uniformity of metal silicide, wherein, the second heat treatment Phase is higher temperature and shorter than the first phase. The present invention uses the above method to prevent the metal silicide from irregularly corroding to the contact surface of the gate structure and the active region, thereby reducing the programming interference caused by the irregular erosion, achieving the purpose of suppressing the programming interference of the flash memory, and further avoiding The reliability of the drain region is reduced during cycle operation, while avoiding the data retention of the flash memory to generate tail bits.

Description

technical field [0001] The invention belongs to the manufacturing field of semiconductor devices, and relates to a preparation method of a flash memory. Background technique [0002] Flash memory (Flash Memory, referred to as flash memory) is a programmable erasable, non-volatile, non-volatile semiconductor memory developed on the basis of the manufacturing technology of EPROM and EEPROM. The advantage of large capacity, and overcome the defects of DRAM and SRAM that lose the stored data when the power is cut off, has become one of the mainstream research in the industry. [0003] Flash memory has been used in thousands of products, including mobile phones, laptops, PDAs, and USB flash drives, because of its ability to retain data in the event of a power failure and the ability to rewrite data multiple times. , and in industrial products such as network routers and cabin recorders. The development of flash memory cells with low power consumption, high reliability and fast ...

AI Technical Summary

Problems solved by technology

[0010] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a method for preparing a flash memory, which is used to solve the problem in the prior art that the metal silicide corrodes irregularly to the contact surface of the gate structure and the active region , which is further used to solve the problem of how to use a simple process in the prior art to make the flash memory effectively avoid programming disturbance

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