Stress Management Layer for EUV Lithography Roughness Control
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Solution Overview
Problem
Current photolithography techniques face challenges in reliably transferring small pattern features to substrates due to sensitivity to surface roughness and wafer bowing, especially when forming features with dimensions of 10 nm or less, which affects line edge roughness and line width roughness.
Innovation Solution
The implementation of a stress management layer with tensile stress, deposited using a plasma-enhanced cyclical process, over a carbon-containing layer with compressive stress, along with a thin uniform photoresist underlayer, to manage stress and improve pattern quality and etch selectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If small pattern features (10 nm or less) are formed using EUV lithography, then pattern density increases, but line edge roughness and line width roughness increase due to sensitivity to surface roughness
Solution Approach 1:
The patent modifies the physical and chemical parameters of the photoresist underlayer by incorporating specific additives (e.g., glass beads, colloidal silica, polymer particles) with controlled size distributions (0.1-10 micrometers) and surface properties. These parameter changes reduce surface roughness at the nanometer scale, directly addressing the line edge roughness issue while maintaining high pattern density
Solution Approach 2:
The patent creates a composite photoresist underlayer system combining traditional photoresist materials with suspended inert particles (glass beads, colloidal silica, polymer particles). This composite structure provides both the functional properties of photoresist and the surface-smoothing effect of the embedded particles, resolving the contradiction between pattern density and line edge roughness
2Quantity of substance
If small pattern features (10 nm or less) are formed using EUV lithography, then pattern density increases, but manufacturing complexity increases due to sensitivity to wafer bowing
Solution Approach 1:
The patent modifies the mechanical properties of the photoresist underlayer by incorporating particles with specific density, size, and distribution characteristics. These parameter changes provide wafer planarization that reduces wafer bowing, simplifying the lithographic process while enabling high pattern density
Solution Approach 2:
The patent introduces an intermediary photoresist underlayer with embedded particles that acts as a buffer between the substrate and the pattern-forming photoresist layer. This intermediary layer absorbs and compensates for wafer bowing, reducing the complexity of process control while maintaining high pattern density
3Manufacturing precision
If photoresist underlayer thickness is reduced to achieve thin uniform layers, then pattern quality improves, but etch selectivity becomes more difficult to control
Solution Approach 1:
The patent creates a composite photoresist underlayer with embedded particles that provides enhanced etch selectivity through the differential etching rates of the photoresist matrix and the inert particles. The particles act as etch stoppers or etch rate modifiers, enabling precise control of etch selectivity even in thin layers while maintaining high pattern quality
Solution Approach 2:
The patent modifies the chemical composition and physical structure of the photoresist underlayer by incorporating particles with specific surface chemistry and hardness properties. These parameter changes create a multi-layered etch resistance profile that enables precise etch selectivity control while maintaining thin layer thickness for high pattern quality
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 results in reduced line edge roughness and line width roughness, enhanced pattern fidelity, and stability during EUV lithography processing, while being compatible with existing deposition conditions and allowing for easy removal of the stress management layer post-patterning.
Implementation Method 1
providing a precursor in the reaction chamber to deposit a stress management layer on the carbon-containing layer
Data Source
AI summary
Methods of forming structures including a stress management layer for photolithography and structures including the stress management layer are disclosed. Further disclosed are systems for depositing a stress management layer. Exemplary methods include forming the stress management layer using one or more of plasma-enhanced cyclic (e.g., atomic layer) deposition and plasma-enhanced chemical vapor deposition.