Forming method of storage

Abstract

The invention provides a forming method of a storage. The forming method includes providing a substrate; forming a floating gate material layer on the substrate; imaging the floating gate material layer and the substrate, and forming floating gates on the substrate and an opening formed in the substrate positioned between the floating gates; forming an isolation material layer in the opening; performing first chemical and mechanical lapping on the tops of the floating gates and the top of the isolation material layer, to planarize the upper surfaces of the floating fates; removing the isolation material layer between the gloating gates, thus allowing the isolation material layer in the substrate to form an isolation structure; forming an insulating layer on the side walls and upper surfaces of the floating gate and the surface of the isolation structure. As the upper surfaces of the floating gates are high in evenness, the insulating layer formed on the upper surfaces of the floating gates are uniform in thickness, sand thereby the local electric field intensity adjacent to the insulating layer is close to the electric field intensity of other areas, and the electric charge maintaining capacity of the floating gates can be improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for forming a memory. Background technique [0002] With the development of the times, the storage of information is becoming more and more important. Non-volatile memory is a more commonly used information memory, which stores 0 / 1 information by storing charges on the floating gate. The non-volatile memory can also resist magnetic interference well when there is no electricity to maintain it, so the non-volatile memory is widely used. [0003] Tunnel oxide layer non-volatile memory (Eprom Tannel Oxide, ETOX) is a more commonly used non-volatile memory. ETOX includes control gate, floating gate, gate oxide layer of floating gate, control gate floating gate insulating layer and source region , Drain region, by applying a voltage to the control gate, the electrons in the source region reach the floating gate under the effect of tunnel effect to realize the write op...

AI Technical Summary

Problems solved by technology

[0004] With the shrinking of the semiconductor feature size, the thickness of the insulating layer in ETOX continues to decrease, and the local electric field strength near the insulating layer is often greater than the surrounding electric field strength, which makes the ability of the floating gate to store charges worse. At present, there is an urgent need for a memory The formation method, without increasing the thickness of the insulating layer, reduces the local electric field strength near the memory, so as to improve the ability of the floating gate to store charges

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