How to make sonos memory

Abstract

The invention discloses a method for manufacturing a SONOS memory, comprising the steps of: forming a first gate structure of a storage tube formed by superimposing an ONO layer and a polysilicon gate; grid structure. Forming the sidewall, including sub-steps: sequentially forming the fourth oxide layer, the fifth nitride layer and the sixth oxide layer; using the fourth oxide layer as a stop layer to etch the sixth oxide layer and the fifth nitride layer in sequence to form side wall. A salicide barrier layer is formed. Etching the salicide barrier layer; in the storage area, the second nitride layer of the ONO layer is used as a stop layer for the etching process of the salicide barrier layer and makes each first in the storage area The outer surface of the gate structure is protected. Salicide growth is performed. The invention can prevent the formation of salicide on the surface of the substrate between the gates of the storage area and thereby prevent the performance of the storage tube from being adversely affected.

Description

technical field [0001] The invention relates to a method for manufacturing a semiconductor integrated circuit, in particular to a method for manufacturing a SONOS memory. Background technique [0002] SONOS is the abbreviation of silicon-oxide-nitride-oxide-silicon. In the manufacturing process of SONOS embedded memory, in order to ensure the smooth integration of the manufacturing process of the storage tube and the contact hole process of the peripheral non-storage tube, the During the side wall process, the ONO at the contact hole position between the storage tubes is etched clean, and the bottom of the contact hole of the storage tube and the contact hole of the non-storage tube are finally formed. The metal silicide formed on the surface of the source and drain regions on the side is prone to produce fine process defects during the formation process, which will have an adverse effect on the performance of the memory. [0003] Such as Figure 1A to Figure 1J Shown is a ...

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Problems solved by technology

[0030] Figure 1G In the storage area 201, the surface of the semiconductor substrate 101 outside each of the first gate structures 203, that is, the surface of the source and drain regions between the outside of each of the first gate structures 203 is formed on the surface of the semiconductor substrate 101. The self-aligned metal silicide 109 is prone to produce small process defects, which will have an adverse effect on the performance of the memory

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