Semiconductor Spacer Structure Preventing Pattern Collapse
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Solution Overview
Problem
Existing semiconductor device structures with fine patterns face limitations in maintaining pattern integrity due to the collapse of photoresist patterns during photolithographic processes, particularly as feature sizes shrink, leading to inadequate resolution and integration capabilities.
Innovation Solution
The semiconductor device structure incorporates inner and outer spacer elements with specific geometric configurations and materials, such as stress-extension and stress-compression films, which are formed over the photoresist patterns to prevent collapse by extending into undercut regions and providing support during etching processes, ensuring the stability of the pattern even after the photoresist removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If photolithography processes are used to fabricate fine patterns, then the degree of integration can be improved, but the photoresist patterns collapse during etching processes
Solution Approach 1:
The patent applies preliminary action by forming spacer elements on the photoresist patterns before the etching process. These spacers extend into the undercut regions of the photoresist, providing structural support that prevents collapse during subsequent etching operations. The spacers are formed in advance to ensure pattern integrity is maintained throughout the fabrication process.
Solution Approach 2:
The spacer elements serve as an intermediary between the photoresist pattern and the etching process. They act as a protective mediator that supports the photoresist structure during etching, allowing the etching to proceed without causing pattern collapse. The spacers are eventually removed after serving their protective function.
2Measurement precision
If the pitch size and critical dimension are reduced, then the resolution is improved, but the photoresist patterns become more prone to collapse
Solution Approach 1:
The patent applies local quality by providing targeted support only where needed - specifically in the undercut regions of the photoresist patterns. The spacer elements are formed conformally on the sidewalls and extend into the undercut regions, providing localized reinforcement to the weakest parts of the pattern structure without affecting the overall pattern dimensions.
Solution Approach 2:
The patent addresses the two-dimensional pattern collapse problem by introducing a three-dimensional solution. The spacer elements extend vertically into the undercut regions, adding a depth dimension to the support structure. This vertical extension provides structural reinforcement that prevents lateral collapse of the fine patterns.
3Reliability
If spacer elements are formed to prevent collapse, then pattern integrity is maintained, but the device structure becomes more complex
Solution Approach 1:
The spacer elements are designed as temporary structures that are discarded after serving their protective function. The spacers are formed to prevent pattern collapse during etching, then removed in a subsequent cleanup step. This approach allows the use of complex spacer structures during fabrication without permanently increasing the complexity of the final device.
Solution Approach 2:
The support structure is segmented into distinct spacer elements rather than using a single monolithic support structure. The spacers are formed conformally on specific regions of the photoresist pattern, providing targeted support where needed. This segmentation allows for more efficient use of materials and simplifies the overall fabrication process compared to using a universal support structure.
Data Source
AI summary
The present disclosure relates to a semiconductor device structure with fine patterns and a method for preparing the semiconductor device structure for preventing the collapse of the fine patterns. The semiconductor device structure includes a first inner spacer element disposed over a top surface of a semiconductor substrate. The first inner spacer element includes a first portion, a second portion, and a third portion between the first portion and the second portion. A height of the first portion and a height of the second portion are less than a height of the third portion, and a width of the first portion increases continuously as the first portion extends toward the top surface of the semiconductor substrate. The semiconductor device structure also includes a first outer spacer element disposed over the second portion of the first inner spacer element.