Cross-linking Polymer Hard Mask for Semiconductor Etching Selectivity
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Solution Overview
Problem
In semiconductor manufacturing, achieving high etching selectivity and preventing photoresist pattern collapse during lithography processes is challenging, especially when forming critical dimensions below 0.07 μm, due to the limitations of conventional anti-reflection and hard mask films.
Innovation Solution
A cross-linking polymer composed of a silicon compound and a hydroxyl compound, combined with an organic solvent and a catalyst, forms a hard mask composition that enhances etching selectivity and light absorbance, allowing for the formation of uniform patterns using DUV light sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If photoresist layer thickness is reduced to prevent pattern collapse, then pattern stability is improved, but etching selectivity deteriorates
Solution Approach 1:
The patent introduces a hard mask layer as an intermediary between the photoresist and the underlying layer. This hard mask layer has high etching selectivity relative to both the photoresist and the underlying layer, allowing the photoresist to be thinner for pattern stability while the hard mask provides the necessary etching protection and selectivity control.
Solution Approach 2:
The patent uses a composite structure consisting of multiple layers: photoresist layer, hard mask layer, and underlying layer. Each layer is made of specific materials with tailored properties - the hard mask layer contains materials with high etching selectivity that work synergistically with the photoresist to resolve the contradiction between pattern stability and etching selectivity.
2Manufacturing precision
If multi-layer hard mask film is formed to secure etching selectivity, then etching selectivity is improved, but process complexity increases
Solution Approach 1:
The patent combines the anti-reflection coating function and the hard mask function into a single integrated hard mask layer. This unified layer simultaneously provides etching selectivity and anti-reflection properties, eliminating the need for separate multi-layer structures and reducing process complexity while maintaining high etching selectivity.
Solution Approach 2:
The hard mask layer is designed to perform multiple functions: it serves as the etching mask providing high etching selectivity, and simultaneously acts as an anti-reflection layer to prevent standing waves and scattered reflection. This multi-functionality reduces the number of separate layers needed and simplifies the overall process.
3Object-affected harmful factors
If organic anti-reflection layer is used, then scattered reflection is reduced, but dissolution by photoresist solvent occurs
Solution Approach 1:
The patent changes the chemical composition parameters of the hard mask layer to create a material that is resistant to photoresist solvents. By selecting specific materials with appropriate chemical properties for the hard mask layer, the layer maintains its structural integrity during photoresist application and development while still providing anti-reflection functionality.
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
The hard mask composition ensures excellent etching selectivity and prevents photoresist pattern collapse, enabling the formation of high-capacity semiconductor devices with improved integrity and simplified process steps.
Implementation Method 1
a cross-linking polymer that includes a silicon compound and a hydroxyl compound
Implementation Method 2
the composition is required to contain a material having a high light absorbance to light sources to inhibit scattered reflection from a bottom layer
Data Source
AI summary
Disclosed herein is a cross-linking polymer that includes a silicon compound and a hydroxyl compound. Also disclosed herein is a composition that includes the cross-linking polymer and an organic solvent. The composition can be used as a part of hard mask film applied over an underlying layer during the manufacture of a semiconductor device. The hard mask film is useful in the formation of a uniform pattern on the device.