Semiconductor Mask Layer Etch Selectivity via Silicon or Titanium Oxide
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Solution Overview
Problem
In semiconductor device fabrication, achieving high etch selectivity during the EUV photolithography process is challenging, particularly when using silicon oxynitride layers as mask layers, as they require high impact energy, leading to process failures where photoresist patterns are removed before the mask layer is partially or completely patterned.
Innovation Solution
Employing a mask layer comprising silicon or titanium oxide instead of silicon oxynitride, which provides increased etch selectivity with respect to photoresist patterns due to their lower binding energy, allowing for effective patterning without significant loss of the photoresist patterns during the etching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If silicon oxynitride layer is used as mask layer, then etching capability is improved, but photoresist pattern is removed before mask layer is patterned
Solution Approach 1:
The patent changes the material composition of the mask layer from silicon oxynitride to materials with lower binding energy (such as silicon oxide, silicon nitride, or titanium oxide). This parameter change in material composition reduces the impact energy required during etching, thereby preventing photoresist pattern removal while maintaining adequate etching capability for the mandrel layer.
2Manufacturing precision
If high impact energy is used for etching silicon oxynitride mask layer, then mask layer patterning is achieved, but photoresist pattern is removed
Solution Approach 1:
The patent modifies the material parameters of the mask layer by selecting materials with lower binding energy than silicon oxynitride. This allows the etching process to use reduced impact energy, sufficient for patterning the mask layer without causing the harmful removal of the photoresist pattern.
3Manufacturing precision
If etch selectivity is increased for mask layer, then mask layer patterning precision is improved, but process margin is reduced
Solution Approach 1:
The patent achieves improved etch selectivity through material composition changes rather than increasing process severity. By using materials with inherently lower binding energy, the process obtains better selectivity with moderate etching conditions, thereby maintaining adequate process margins while achieving precise mask layer patterning.
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 enables the formation of precise target patterns with improved etch selectivity, reducing process failures and enhancing the ability to create fine patterns in semiconductor devices.
Implementation Method 1
irradiating an extreme ultraviolet (EUV) radiation on the photoresist layer to form a photoresist pattern
Implementation Method 2
patterning the first mask layer to form a first mask pattern using the photoresist pattern as an etching mask
Implementation Method 3
patterning the etching target layer to form a target pattern using the first mask pattern as an etching mask
Data Source
AI summary
Example embodiments relate to a method for fabricating a semiconductor device. The method for fabricating a semiconductor device includes stacking on a substrate an etching target layer, a first mask layer, and a photoresist layer, irradiating extreme ultraviolet (EUV) radiation on the photoresist layer to form a photoresist pattern, patterning the first mask layer to form a first mask pattern using the photoresist pattern as an etching mask, and patterning the etching target layer to form a target pattern using the first mask pattern as an etching mask. The first mask layer includes at least one of a silicon layer and a titanium oxide layer.