Block Copolymer Self-Assembly for Semiconductor Pattern Resolution
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Solution Overview
Problem
Conventional photolithography processes face challenges in forming patterns with critical dimensions below a certain level due to resolution limits, and double patterning methods are complex and costly, necessitating the development of alternative techniques for semiconductor device manufacturing.
Innovation Solution
A direct self-assembly (DSA) method using block copolymers is employed, where guiding pillars and dams are formed on a substrate, and a self-aligned layer is created using polymethylmethacrylate (PMMA) and polystyrene (PS) to align blocks radially around pillars and linearly along dams, allowing for the formation of precise patterns through the transfer of these blocks into the object layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photolithography process is used to form fine patterns, then manufacturing capability is maintained, but pattern resolution is limited below a specific critical dimension
Solution Approach 1:
The patent divides the patterning process into multiple stages by forming mandrels and then using block copolymer self-assembly to create additional patterns between the mandrels. This segmentation allows the final pattern to achieve resolution beyond the limitations of single-step photolithography, as the block copolymer domains form at a smaller scale than the mandrel spacing.
Solution Approach 2:
The patent introduces block copolymer as an intermediary material that self-assembles between the photolithographically-formed mandrels. This intermediary enables the transfer of patterns at a finer resolution than the original mandrels, effectively mediating between the limited photolithography resolution and the desired fine pattern dimensions.
2Manufacturing precision
If double patterning method is used to form fine patterns, then pattern resolution is improved, but process complexity and manufacturing cost increase
Solution Approach 1:
The patent employs self-service by utilizing the spontaneous self-assembly of block copolymers to form patterns without requiring additional photolithography steps or complex alignment processes. The block copolymer domains automatically organize into ordered structures based on their phase separation, eliminating the need for manual intervention or complex equipment for the second patterning step.
Solution Approach 2:
The patent changes the physical and chemical parameters of the system by introducing block copolymer materials with specific domain sizes and self-assembly characteristics. By controlling parameters such as block copolymer composition, film thickness, and annealing conditions, the patent achieves fine pattern formation through material property changes rather than additional processing steps.
3Manufacturing precision
If double patterning method is used to form fine patterns, then pattern resolution is improved, but manufacturing cost increases
Solution Approach 1:
The patent uses mandrels as temporary, disposable structures that are formed by photolithography and then removed after serving their purpose as pattern templates. These mandrels are replaced by the self-assembled block copolymer patterns, which are formed without requiring additional expensive equipment or materials. The mandrels are discarded after transferring their pattern information, reducing overall manufacturing cost.
Solution Approach 2:
The patent replaces mechanical or chemical etching processes with a physical self-assembly mechanism. Instead of using complex chemical reactions or mechanical patterning tools for the second patterning step, the system utilizes the inherent self-organizing behavior of block copolymers, which naturally form ordered patterns through minimization of free energy. This substitution eliminates the need for additional expensive equipment and reduces manufacturing complexity.
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 method enables the formation of fine patterns with improved precision and reduced complexity, facilitating the creation of semiconductor devices with smaller feature sizes and lower production costs by utilizing the self-aligned block copolymer layer to form contact holes and other patterns efficiently.
Implementation Method 1
a self-aligned layer including a block copolymer may be formed in a space between the guiding pillars and the guiding dam, such that first blocks aligned around the guiding pillars and second blocks aligned around the guiding dam may be formed
Data Source
AI summary
In a method of forming patterns of a semiconductor device, an object layer is formed on a substrate. A plurality of guiding pillars and at least one guiding dam are formed on the object layer. A self-aligned layer including a block copolymer is formed in a space between the guiding pillars and the guiding dam, such that first blocks aligned around the guiding pillars and second blocks aligned around the guiding dam are formed. A trim pattern at least partially covering the guiding dam is formed. The first blocks are transferred in the object layer.