Carbon Spacer for MTJ Patterning in Semiconductor Fabrication
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Solution Overview
Problem
The manufacturing process of semiconductor devices with integrated magnetic tunnel junction (MTJ) elements is complex due to the need for separate patterning processes for the MTJ element and the electrode layers, which complicates the fabrication and increases the risk of contamination and damage to the MTJ element during the etching and cleaning processes.
Innovation Solution
A carbon spacer is formed in-situ during the etching process of the MTJ element, serving as a protective barrier and etch mask to simplify the patterning of the bottom electrode layer in the same chamber, reducing the number of process steps and minimizing contamination risks, while allowing the use of Cl or F-based etching gases without damaging the MTJ element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If separate patterning processes are used for MTJ element and electrode layers, then the MTJ element can be precisely patterned, but the manufacturing process becomes complex and the risk of contamination and damage increases
Solution Approach 1:
The patent combines the patterning of the MTJ element and the electrode layers into a single patterning process by using a unified etch mask pattern. This merging approach eliminates the need for separate patterning steps, thereby reducing manufacturing process complexity while maintaining patterning precision through the protective carbon spacer that prevents damage during the combined process
2Manufacturing precision
If separate patterning processes are used for MTJ element and electrode layers, then each layer can be optimized, but the number of process steps increases
Solution Approach 1:
The patent merges multiple patterning operations into a single etching process step, using the carbon spacer to protect the MTJ element while patterned the electrode layers. This consolidation reduces the total number of process steps and improves manufacturing efficiency while maintaining the ability to optimize each layer's pattern independently through the selective protection mechanism
3Ease of manufacture
If traditional etching and cleaning processes are used, then the bottom electrode layer can be processed, but the MTJ element is at risk of damage and contamination
Solution Approach 1:
The patent introduces a carbon spacer as an intermediary protective layer between the MTJ element and the etching/cleaning processes. This carbon spacer acts as a mediator that allows traditional etching and cleaning processes to be performed on the bottom electrode layer while protecting the MTJ element from damage and contamination, thereby maintaining both ease of manufacture and reliability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach simplifies the semiconductor device fabrication process by reducing the number of process steps, minimizing contamination, and enabling safe etching and cleaning of the bottom electrode layer without compromising the MTJ element's properties, thereby improving the manufacturing efficiency and reducing the risk of damage.
Implementation Method 1
forming a carbon spacer on the sidewalls of the MTJ pattern and the top layer pattern
Implementation Method 2
forming a carbon spacer on the sidewalls of the MTJ pattern and the top layer pattern
Implementation Method 3
patterning the top layer and the MTJ layer using an etch mask pattern to form a top layer pattern and an MTJ pattern
Data Source
AI summary
A method for fabricating a semiconductor device includes forming a plurality of layers which are stacked as a bottom layer, an MTJ layer, and a top layer, patterning the top layer and the MTJ layer using an etch mask pattern to form a top layer pattern and an MTJ pattern, forming a carbon spacer on the sidewalls of the MTJ pattern and the top layer pattern to protect the MTJ pattern and the top layer pattern, and patterning the bottom layer using the carbon spacer and the etch mask pattern as an etch mask to form a bottom layer pattern.