Manufacture method of storage device

Abstract

The invention relates to a manufacture method of a storage device. The manufacture method comprises the steps of providing a substrate, wherein the substrate comprises a storage unit area and a peripheral area; forming a plurality of first grid electrodes in the storage unit area and forming at least one second grid electrode in the peripheral area; forming a sacrifice layer on the substrate; forming a first stop layer on the sacrifice layer in the storage unit area; carrying out the etching process by adopting the first stop layer as a mask; sequentially forming a second stop layer on the substrate; depositing a dielectric material on the second stop layer; carrying out the flattening process for the dielectric material by adopting the first stop layer and the second stop layer in the storage unit area as a grinding stop layer; removing the first stop layer and the second stop layer in the storage unit area; removing the sacrifice layer in the storage unit area so as to forming a plurality of first contact openings among the first grid electrodes after the first stop layer and the second stop layer are removed. The stop layers in different thicknesses are formed in the storage unit area and the peripheral area, so that a landing area contacting a plug is not compressed while the size of the storage device is further reduced.

Description

technical field [0001] The present invention relates to a manufacturing method of a memory. Background technique [0002] Generally speaking, as the size of the memory is gradually reduced, in order to overcome the smaller and smaller line width and prevent the misalignment of the contact plugs, self-aligned contact plugs (SAC) are used. craft. [0003] In the self-aligned contact plug process, the thickness of the gate sidewalls affects the size of the contact plugs formed between the gates. The memory element includes a memory cell region and a peripheral region. Generally, gates are formed in the memory cell region and the peripheral region at the same time. Afterwards, an etching process is performed on the sidewalls of the gate to facilitate subsequent formation of contact plugs. [0004] However, in some memory structures, metal silicides are formed on the gate, source and drain regions in the peripheral region. If the sidewall of the gate is etched, the metal sili...

AI Technical Summary

Problems solved by technology

If the sidewall of the gate is etched, the metal silicide will be exposed, which will affect the electrical characteristics of the memory

Therefore, in the memory structure with metal silicide formed on the gate and source / drain regions of the peripheral region, the spacer (sidewall) of the gate cannot be etched, which affects the formation of subsequent contact plugs

Therefore, when the size of the memory is further reduced, there will be a problem that the landing area of ​​the contact plug is compressed.

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