Tungsten Hard Mask Structure for Oxidation-Resistant Patterning
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Solution Overview
Problem
Existing semiconductor manufacturing processes face challenges in forming high aspect ratio features due to oxidation of metal hard masks, which affects critical dimensions and uniformity, necessitating improved materials and etching chemistries for precise patterning.
Innovation Solution
A method involving the formation of a metal mask layer with tungsten and nitrogen, combined with nitrogen-containing barrier layers and oxygen-containing dielectric layers, is used to create a hard mask structure that protects against oxidation and enables precise patterning and etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a metal hard mask layer is used for high aspect ratio etching, then etch selectivity and critical dimension control are improved, but oxidation of the metal mask layer occurs affecting manufacturing precision
Solution Approach 1:
A nitrogen-containing barrier layer is introduced as an intermediary between the metal mask layer and the oxygen-containing dielectric layer. This barrier layer prevents oxygen diffusion to the metal mask layer, eliminating oxidation while maintaining the etch selectivity and critical dimension control benefits of the metal hard mask structure.
Solution Approach 2:
The harmful oxygen element is extracted from the vicinity of the metal mask layer by placing a nitrogen-containing barrier layer between the metal mask and oxygen-containing dielectric materials. This separation prevents the harmful interaction (oxidation) while allowing the structure to maintain its functional benefits.
2Area of moving object
If size and geometry scaling continues to shrink in semiconductor devices, then device density is improved, but achieving target critical dimensions and pattern uniformity becomes more difficult
Solution Approach 1:
The invention changes the chemical composition parameters of the barrier layer (nitrogen-containing materials such as silicon nitride, silicon oxynitride, or carbon nitride) to create a diffusion barrier that prevents oxygen from reaching the metal mask layer. This parameter change maintains pattern uniformity and critical dimensions even as device features scale to smaller dimensions.
Solution Approach 2:
The invention uses composite material structures combining metal mask layers with nitrogen-containing barrier layers and oxygen-containing dielectric layers. This composite structure provides both the etch selectivity of metal hard masks and protection against oxidation, enabling precise patterning at scaled dimensions.
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 ensures precise and uniform formation of high aspect ratio features by preventing oxidation of the metal mask layer, maintaining critical dimensions, and enhancing etch selectivity, thereby improving semiconductor device quality and density.
Implementation Method 1
forming a barrier layer directly on the metal mask layer, where the barrier layer contains nitrogen
Implementation Method 2
patterning and etching the dielectric layer and the barrier layer to form holes through the dielectric layer and the barrier layer
Data Source
AI summary
A method for forming a semiconductor device can include forming a metal mask layer on a substrate, where the metal mask layer contains tungsten, and forming a patterned mask directly on the metal mask layer, where the forming of the patterned mask includes forming a barrier layer directly on the metal mask layer, where the barrier layer contains nitrogen, forming a dielectric layer directly on the barrier layer, where the dielectric layer contains oxygen, and patterning and etching the dielectric layer and the barrier layer to form holes through the dielectric layer and the barrier layer, such that the holes open to the metal mask layer.