Minute Island Pattern Formation via Multi-Layer Mask Segmentation
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Solution Overview
Problem
Conventional methods struggle to form island-type patterns with widths of 100 nm or less on semiconductor substrates due to limitations in photoresist pattern resolution and stability during etching, resulting in non-uniform patterns.
Innovation Solution
A method involving the formation of a recess region in a mask layer using a photoresist pattern, followed by alternating layers of a second mask layer and etching, with an ion beam at an incidence angle greater than 0°, to create a minute island-type pattern with precise control over etching rates and material selectivity, allowing for the formation of patterns with widths as low as 50 nm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a photoresist pattern with width of 100 nm or less is formed, then the resolution of the pattern is improved, but the photoresist pattern is easily separated during etching, generating non-uniform patterns
Solution Approach 1:
The mask layer is divided into multiple sub-layers through alternating deposition and etching processes. Each sub-layer provides structural support, preventing the photoresist pattern from separating during etching while maintaining the desired 100 nm or less pattern width. This segmentation approach resolves the contradiction by providing internal reinforcement without increasing the overall pattern dimensions.
Solution Approach 2:
The mask layer and its sub-layers are formed in advance before the final etching of the electrode layer. This preliminary structuring ensures that the mask maintains its integrity throughout the subsequent etching process, preventing pattern separation and ensuring uniformity of the minute patterns being formed.
2Area of moving object
If the width of the island-type pattern is reduced to 100 nm or less, then the integration density is improved, but the formation of etch masks with similarly low widths becomes difficult due to limited resolution of exposure equipment
Solution Approach 1:
The solution transitions from a single-layer mask approach to a multi-layer mask structure with vertical dimensionality. By forming the mask layer with multiple sub-layers at different depths, the system achieves the required horizontal resolution (100 nm or less) that cannot be obtained with conventional single-layer photolithography, effectively using the vertical dimension to overcome horizontal resolution limitations.
Solution Approach 2:
Multiple sub-layers are nested within the mask layer structure, with each sub-layer contained within the overall mask geometry. This nested configuration allows the formation of complex multi-layer patterns that maintain the small 100 nm or less width requirement while providing the structural complexity needed for precise pattern formation.
3Device complexity
If a single mask layer is used for etching, then the process complexity is reduced, but the mask cannot provide sufficient precision for forming minute patterns with width of 100 nm or less
Solution Approach 1:
The single mask layer is segmented into multiple sub-layers, each contributing to the overall precision of the pattern formation. This segmentation allows for better control of the etching process at different depths, achieving the 100 nm or less width precision that a single layer cannot provide.
Solution Approach 2:
Different sub-layers of the mask can have different properties or thicknesses optimized for specific functions. This local quality variation within the mask structure enables precise control over the etching process at different locations and depths, achieving the required manufacturing precision for minute patterns.
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 highly integrated semiconductor devices with uniform, minute island-type patterns, improving the resolution and reliability of pattern formation in semiconductor memory devices.
Implementation Method 1
etching the material layer to form a material layer pattern. The etching of the layer processing may include using an ion beam. Using the ion beam may include adjusting an ion beam apparatus at an incidence angle larger than 0°.
Data Source
AI summary
A method for forming a minute pattern includes depositing a material layer on a semiconductor substrate having a conductive region, forming a first mask layer on the material layer, forming a recess region in the first mask layer, performing layer processing to form a first mask pattern in the recess region, and etching the material layer to form a material layer pattern.