Sub-Resolution Feature Formation in Semiconductor Devices
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Summary
Problems
Conventional photolithography techniques have limitations in forming features with dimensions below a certain critical size due to optics limitations and wavelength constraints, making it difficult to achieve smaller pitch and critical dimensions in semiconductor devices.
Innovation solutions
The anti-spacer process is employed, which involves chemically modifying the outer portions of photosensitive materials to make them soluble, forming filler materials between them, and removing these portions to create trenches and openings, allowing for the formation of features with smaller dimensions by extending holes into the substrate, thereby reducing the complexity and cost compared to conventional pitch multiplication techniques.
TRIZ Analysis
Specific contradictions:
General conflict description:
Principle concept:
If conventional photolithography techniques are used, then features can be formed with standard dimensions, but features with critical dimensions below 37.5 nm cannot be reliably formed due to optics limitations and radiation wavelength constraints
Why choose this principle:
The process segments feature formation into multiple steps: first forming a mandrel pattern at a larger pitch, then forming spacers on mandrel sidewalls, removing mandrels, and repeating the process to achieve sub-37.5 nm critical dimensions. This segmentation allows each step to operate within reliable photolithography limits while achieving smaller final dimensions
Principle concept:
If conventional photolithography techniques are used, then features can be formed with standard dimensions, but features with critical dimensions below 37.5 nm cannot be reliably formed due to optics limitations and radiation wavelength constraints
Why choose this principle:
The invention uses the vertical dimension by forming three-dimensional spacer structures on mandrel sidewalls. The spacer thickness, controlled by conformal deposition, defines the final feature dimension, transitioning from two-dimensional planar lithography to three-dimensional structure-based dimensioning
Application Domain
Data Source
AI summary:
The anti-spacer process is employed, which involves chemically modifying the outer portions of photosensitive materials to make them soluble, forming filler materials between them, and removing these portions to create trenches and openings, allowing for the formation of features with smaller dimensions by extending holes into the substrate, thereby reducing the complexity and cost compared to conventional pitch multiplication techniques.
Abstract
Methods of forming semiconductor devices and features in semiconductor device structures include conducting an anti-spacer process to remove portions of a first mask material to form first openings extending in a first direction. Another anti-spacer process is conducted to remove portions of the first mask material to form second openings extending in a second direction at an angle to the first direction. Portions of the second mask material underlying the first mask material at intersections of the first openings and second openings are removed to form holes in the second mask material and to expose a substrate underlying the second mask material.