Double Patterning Contact Hole Lithography
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Solution Overview
Problem
Conventional double patterning processes for semiconductor technologies involve multiple etching processes, leading to high manufacturing costs and low throughput, especially when dealing with small feature sizes and high aspect ratio patterned photoresist layers.
Innovation Solution
A double patterning method that involves forming a first resist pattern on a substrate, baking it, and then forming a second resist layer within the openings of the baked pattern, followed by a single etching process to transfer the pattern into the underlying material layer, reducing the need for multiple etching steps and enhancing manufacturing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional double patterning processes are used, then small feature sizes can be achieved, but manufacturing cost increases and throughput decreases
Solution Approach 1:
The patent combines multiple etching processes into a single etching step by using a self-aligned double patterning approach. The first resist pattern serves as both the initial mask and the alignment reference for the second resist pattern, eliminating the need for separate etching steps that would otherwise be required for each pattern layer.
Solution Approach 2:
The patent performs preliminary patterning by forming the first resist pattern and performing a single etching process before forming the second resist pattern. This preliminary action creates a self-aligned reference structure that guides subsequent patterning steps, reducing the need for repeated etching processes.
2Manufacturing precision
If conventional double patterning processes are used, then small feature sizes can be achieved, but manufacturing cost increases
Solution Approach 1:
The patent merges multiple etching processes into one by utilizing the self-aligned nature of the double patterning approach. The first resist pattern and its corresponding etched structure serve as the alignment reference for the second pattern, eliminating redundant etching steps and associated costs.
Solution Approach 2:
The first resist pattern and the etched structure it creates serve a dual purpose: they are both the initial pattern and the alignment reference for the second pattern. This self-service approach eliminates the need for separate alignment marks and reduces the number of process steps required.
3Manufacturing precision
If high aspect ratio patterned photoresist layers are used, then small feature sizes can be achieved, but maintaining desired critical dimension becomes difficult
Solution Approach 1:
The patent segments the patterning process into two separate resist pattern formations, with each pattern having a lower aspect ratio requirement. By dividing the overall pattern into two self-aligned stages, each resist layer can be formed with more manageable thickness-to-width ratios, improving CD control.
Solution Approach 2:
The patent transitions from forming a single high-aspect-ratio pattern to forming two separate lower-aspect-ratio patterns in sequence. This dimensional approach allows each resist layer to be optimized for its specific function, with the first pattern providing the initial structure and the second pattern adding the final features with better CD control.
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 reduces manufacturing costs and minimizes critical dimension variations, improving throughput and product quality by allowing for the formation of smaller feature sizes with reduced overlay errors and maintaining high etch resistance.
Implementation Method 1
the first positive resist pattern is insoluble in the second positive resist layer
Data Source
AI summary
A method of lithography patterning includes forming a first resist pattern on a substrate, wherein the first resist pattern including a plurality of openings. A second resist pattern is formed on the substrate and within the plurality of openings of the first resist pattern, wherein the second resist pattern includes at least one opening therein on the substrate. The first resist pattern is removed to uncover the substrate underlying the first resist pattern.