HAR Semiconductor Feature Processing Against Drying-Induced Inclination
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Solution Overview
Problem
High aspect ratio (HAR) semiconductor structures are prone to inclination and defects during cleaning and drying processes due to capillary forces, leading to complex and costly issues in semiconductor manufacturing.
Innovation Solution
A semiconductor structure processing method involving ashing, cleaning with an oxide layer formation, and controlled drying to mitigate inclination, followed by oxide layer removal to restore feature portions to a vertical state, using oxygen-free and oxygen-containing ashing processes, and chemical etching with specific gas mixtures to manage capillary forces effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional cleaning and drying processes are used on HAR structures, then the manufacturing process remains simple, but the HAR structures suffer from inclination and collapse due to capillary forces
Solution Approach 1:
A support layer is formed at the bottom of the HAR structure before the cleaning and drying processes. This preliminary structural reinforcement prevents inclination and collapse during subsequent processing steps, allowing conventional simple cleaning and drying methods to be used without compromising the vertical alignment of the HAR structure.
Solution Approach 2:
The support layer acts as a cushioning element that provides mechanical support to the HAR structure before capillary forces can cause inclination or collapse. By preparing this support structure in advance, the patent protects the HAR structure from the harmful effects of capillary forces during cleaning and drying, maintaining manufacturing precision while keeping the process simple.
2Manufacturing precision
If complex processing procedures are implemented to prevent HAR structure inclination, then the vertical alignment improves, but the manufacturing cost and process complexity increase
Solution Approach 1:
The support layer is formed as a preliminary structural element before the HAR structure undergoes cleaning and drying. This single preparatory step provides ongoing protection against inclination throughout the manufacturing process, achieving high vertical alignment without requiring complex multi-step procedures during cleaning and drying.
Solution Approach 2:
The support layer serves as an intermediary element between the substrate and the HAR structure. It mediates the mechanical stresses and capillary forces that would otherwise cause inclination, providing a simple yet effective solution that maintains vertical alignment without complicating the overall processing procedure.
3Productivity
If the depth of feature portions is increased or width decreased to maintain feature density, then the aspect ratio increases, but the HAR structures become more prone to lateral bending, necking, and inclination
Solution Approach 1:
The support layer is formed in advance at the base of the HAR structure, providing a foundation that reinforces the structure against lateral bending, necking, and inclination. This preliminary reinforcement enables the fabrication of high aspect ratio structures with increased depth or decreased width while maintaining the necessary mechanical stability.
Solution Approach 2:
The support layer provides beforehand cushioning and mechanical reinforcement to the HAR structure, compensating for the increased susceptibility to deformation that results from higher aspect ratios. This allows the patent to achieve high feature density through increased depth or reduced width while maintaining structural reliability.
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 method effectively reduces inclination of HAR structures, improves processing quality, and maintains a low-cost, simple process flow by compensating for capillary forces and restoring feature portions to their initial state, thereby enhancing semiconductor manufacturing efficiency.
Implementation Method 1
chemical etching with specific gas mixtures to manage capillary forces effectively
Implementation Method 2
HAR structures are prone to inclination and defects during cleaning and drying processes due to capillary forces
Data Source
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AI summary
A semiconductor structure processing method and forming method are provided. The semiconductor structure processing method comprises the steps of: providing a semiconductor substrate (111), which is provided with feature portions (112) having a mask layer (200) on their top surfaces; ashing a semiconductor structure comprising the semiconductor substrate (111), the feature portions (112) and the mask layer (200); removing the mask layer (200); cleaning the semiconductor structure, and forming an oxide layer (120) on surfaces of the feature portions (112) after the feature portions (112) are cleaned; drying the semiconductor structure; and removing the oxide layer (120). During drying, one feature portion of at least one group of adjacent feature portions (112) is inclined towards a feature portion (112) adjacent thereto, and a distance between the inclined feature portion (112) and the feature portion (112) adjacent thereto after drying is smaller than a distance therebetween before drying.