Semiconductor Assist Layer Polymer for FinFET Patterning
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Solution Overview
Problem
The increasing complexity and difficulty in manufacturing semiconductor devices at smaller sizes due to the challenges in forming reliable semiconductor structures with advanced lithography processes and materials, particularly in achieving precise patterning and reducing line width roughness in FinFET devices.
Innovation Solution
The use of an assist layer with a polymer backbone, acid labile group, and floating group in combination with a chemically amplified resist layer, which undergoes exposure and post-exposure baking to enhance pattern resolution and reduce line width roughness through intermolecular forces and improved solubility, along with a tri-layer photoresist structure for precise etching and doping processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If advanced lithography processes are used to manufacture semiconductor devices at smaller sizes, then feature size reduction is achieved, but manufacturing complexity and difficulty increase
Solution Approach 1:
The patent applies segmentation by dividing the lithography process into multiple sequential steps: forming a first resist pattern, performing a first etch, forming a second resist pattern, and performing a second etch. This multi-step approach breaks down the complex task of creating fine-featured semiconductor devices into manageable stages, allowing each step to be optimized independently while achieving the overall goal of reduced feature size
Solution Approach 2:
The patent employs preliminary action through the formation of mandrels and sacrificial structures before final pattern transfer. The first resist pattern and etched features serve as preliminary structures that guide subsequent processing steps, enabling precise control over final feature dimensions and reducing manufacturing complexity
2Manufacturing precision
If conventional single-layer resist is used, then process simplicity is maintained, but pattern resolution and line width control are insufficient
Solution Approach 1:
The patent applies local quality by using different resist materials with distinct properties for different patterning needs. The first resist is optimized for forming initial mandrels, while the second resist is optimized for final pattern transfer. Each resist layer has tailored chemical and physical properties suited to its specific function, enabling superior pattern resolution without requiring a single complex resist formulation
Solution Approach 2:
The patent employs composite materials by combining multiple resist layers with different compositions and properties. The first resist may contain materials optimized for mandrel formation, while the second resist contains materials optimized for high-resolution pattern transfer. This composite resist structure achieves superior overall performance that neither single resist could achieve alone
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 improves pattern resolution, reduces line width roughness by 10% to 50%, and enlarges the collapse window, enhancing the lithography process for semiconductor device fabrication, particularly suitable for FinFET structures.
Implementation Method 1
the first polymer reacts with a polymer in the resist layer to form an intermolecular force between the first polymer and the polymer in the resist layer
Implementation Method 2
chemically amplified resist layer, which undergoes exposure and post-exposure baking to enhance pattern resolution and reduce line width roughness
Data Source
AI summary
A method for forming a semiconductor device structure is provided. The method includes forming an assist layer over a material layer. The assist layer includes a first polymer with a first polymer backbone, a floating group bonded to the first polymer backbone, and the floating group includes carbon fluoride (CxFy), and a second polymer. The method includes forming a resist layer over the assist layer, and the first polymer is closer to an interface between the assist layer and the resist layer than the second polymer. The method also includes patterning the resist layer.