Semiconductor Patterning Using ALD Spacers and Selective Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current double and quadruple patterning technologies face challenges in achieving precise rectangular features due to overlay errors, edge placement errors, and etch proximity effects, making it difficult to pattern features below 10 nm in size.
Innovation Solution
A method involving the formation of line clusters with core lines and spacers made from different materials, followed by gap filling and selective etching, to create rectangular openings, utilizing atomic layer deposition (ALD) and etching processes, along with a cluster tool arrangement for efficient patterning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If double patterning or quadruple patterning is used to pattern features below 10 nm, then the feature size can be reduced, but overlay errors and edge placement errors become more pronounced
Solution Approach 1:
The patent divides the patterning process into multiple independent stages: forming first line clusters with spacers, depositing gap fill material, forming second line clusters with spacers, and selective removal. Each stage is self-aligned and independent, eliminating overlay errors between stages while enabling sub-10nm feature patterning
Solution Approach 2:
The patent transitions from planar 2D patterning to 3D vertical structures by forming line clusters with spacers extending in the vertical dimension. This allows pattern definition through vertical spacer formation rather than horizontal lithographic alignment, eliminating overlay errors
2Length of moving object
If double patterning or quadruple patterning is used to pattern rectangular features, then smaller features can be achieved, but etch proximity effects become more pronounced
Solution Approach 1:
The patent segments the rectangular feature formation into independent line cluster formations along different directions. First line clusters are formed along a first direction, then second line clusters along a second direction, with gap fill material between them. This segmentation isolates etch processes, reducing proximity effects
Solution Approach 2:
The patent introduces gap fill material as an intermediary layer between first and second line clusters. This intermediary layer physically separates the line clusters, preventing etch proximity effects while maintaining the ability to form precise rectangular features through selective removal
3Shape
If multiple exposures are used for patterning cuts, then rectangular features can be formed, but edge placement errors increase
Solution Approach 1:
Instead of using multiple lithographic exposures to define rectangular features directly, the patent inverts the approach: it forms line clusters with spacers, deposits gap fill material, forms additional line clusters, and then selectively removes materials. The rectangular features emerge from the inverse process of selective removal rather than direct positive definition
Solution Approach 2:
The spacers and gap fill material serve dual purposes: they define the pattern geometry and simultaneously protect regions that should not be etched. The structure serves itself as the patterning mask, eliminating the need for separate lithographic alignment steps and reducing edge placement errors
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 rectangular features by controlling the dimensions and positions of the line clusters and spacers, reducing errors and improving the accuracy of patterning, thus addressing the limitations of existing technologies.
Implementation Method 1
depositing a first material over the core lines by ALD
Data Source
AI summary
Embodiments of the present disclosure provide methods for patterning rectangular features with a sequence of lithography, atomic layer deposition (ALD) and etching. Embodiment of the present disclosure includes forming first line clusters along a first direction and second line clusters over the first line clusters in a direction traversing the first direction. The first and second line clusters both include core lines formed from a core material, spacers formed from first and second materials by ALD and etching. After formation of the first and second line clusters, rectangular openings can be formed by selectively etching one or two of the core material, the first material or the second material.