Gate stack structure suitable for semiconductor flash memory device and manufacturing method of gate stack structure

Abstract

The invention relates to a gate stack structure suitable for a semiconductor flash memory device and a manufacturing method of the gate stack structure. In the gate stack structure, a P-type monocrystalline silicon wafer with crystallographic orientation of 100 is used as a substrate; and an Al2O3 film used as a charge tunneling layer, ruthenium-based RuOx nano-crystals used as a first charge trapping layer, a high dielectric constant HfxAlyOz film used as a second charge trapping layer, an Al2O3 film used as a charge barrier layer and an upper electrode layer are arranged on the substrate from bottom to top sequentially. In the invention, the ruthenium-based RuOx nano-crystals have high thermal stability and are difficult to diffuse at high temperature; the high dielectric constant HfxAlyOz film has higher charge trap density; and an upper electrode is made of metal palladium and has a higher work function. Therefore, the gate stack structure disclosed by the invention has wide application prospect in a nano-crystal memory capacitor.

Description

technical field [0001] The invention belongs to the technical field of semiconductor integrated circuit manufacturing, and in particular relates to a capacitor structure and a preparation method of a flash memory, in particular to a gate stack in which a novel heterogeneous charge trapping layer is formed based on a metal nanocrystal and a high dielectric constant medium Structure and preparation method. Background technique [0002] With the continuous development of semiconductor process technology, the integration density of non-volatile flash memory is getting higher and higher, and the operating voltage is getting lower and lower, which drives the continuous reduction of device feature size. After the 65 nm technology node, the traditional polysilicon floating gate There are a series of problems in the structure, which greatly affect the performance of device storage, such as slow erasing and writing speed, high working voltage and so on. [0003] A new generation of n...

AI Technical Summary

Problems solved by technology

But the disadvantage of this structure memory is that its operating voltage is higher and the operating speed is slower

Images