Stacked Memory Cell Structure With Etch-Resistant Barrier Films
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the manufacturing of semiconductor devices with stacked films alternately comprising electrode and insulating layers, existing methods face challenges in preventing variations in threshold voltage and resistance due to etching of insulating layers during sacrificial layer removal, which can lead to uneven layer thickness and performance issues.
Innovation Solution
Incorporating films made of carbon, germanium, tin, aluminum, phosphorus, or arsenic between electrode and insulating layers, which act as protective barriers resistant to chemical etching solutions, thereby maintaining the integrity and thickness of insulating layers and preventing exposure to etching agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If sacrificial layers are removed by chemical etching to form electrode layers, then the electrode structure can be formed, but the insulating layers may be etched and damaged causing thickness variation and threshold voltage instability
Solution Approach 1:
A protective film made of carbon, germanium, tin, aluminum, phosphorus, or arsenic is introduced as an intermediary layer between the sacrificial electrode layer and the insulating layer. This protective film acts as a mediator that is resistant to chemical etching solutions, preventing the etching agent from damaging the insulating layer while allowing the sacrificial layer to be removed. The protective film maintains insulating layer thickness uniformity during the electrode formation process.
Solution Approach 2:
The protective film is formed on the insulating layer before the chemical etching process begins. This preliminary protective coating prevents the etching solution from directly contacting and damaging the insulating layer during subsequent sacrificial layer removal. The protective film is later removed after serving its protective function, leaving the insulating layer intact with uniform thickness.
2Ease of manufacture
If chemical etching is used to remove sacrificial layers, then electrode layers can be formed, but variations in threshold voltage and resistance occur due to insulating layer damage
Solution Approach 1:
The protective film serves as a chemical barrier that prevents etching solutions from damaging the insulating layer during sacrificial layer removal. By introducing this intermediary protective layer, the reliability of the device is improved through consistent insulating layer properties, which directly stabilizes threshold voltage and resistance characteristics of the resulting transistors.
3Device complexity
If no protective measure is taken during sacrificial layer removal, then the manufacturing process is simpler, but insulating layers are exposed to etching agents causing structural degradation
Solution Approach 1:
The protective film is applied to the insulating layer before the chemical etching process begins. This preliminary protective measure ensures that the insulating layer is shielded from etching agents during sacrificial layer removal. The additional step of forming and later removing the protective film is justified by the significant improvement in insulating layer integrity and device performance.
Data Source
AI summary
In one embodiment, a semiconductor device includes a stacked film alternately including a plurality of electrode layers and a plurality of insulating layers, a charge storage layer provided on a side face of the stacked film via a first insulator, and a semiconductor layer provided on a side face of the charge storage layer via a second insulator. The device further includes a third insulator provided between an electrode layer and an insulating layer in the stacked film and between the electrode layer and the first insulator, and a first film provided between the third insulator and the insulating layer and/or between the third insulator and the first insulator, and including carbon, germanium, tin, aluminum, phosphorus or arsenic.