Metal-Containing Photoresist Overcoat for Clean Semiconductor Patterning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices shrink in size, the challenges of maintaining process windows for photolithographic processing become increasingly tight, and metal-containing photoresists can cause contamination and defects due to outgassing, necessitating improved methods for forming and patterning semiconductor features.
Innovation Solution
A protective layer is formed over a metal-containing photoresist layer on a substrate, with solvent-free photoresist layer formation and selective exposure to actinic radiation, followed by a post-exposure bake and development to prevent outgassing and contamination, while allowing for precise pattern formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If metal-containing photoresist is used to enable patterning of smaller semiconductor features, then manufacturing precision is improved, but contamination and defects occur due to outgassing
Solution Approach 1:
The photoresist layer is segmented into multiple functional layers: a metal-containing photoresist layer for pattern formation and an overcoat layer applied thereover. This segmentation allows the metal-containing layer to provide precise patterning while the overcoat layer prevents metal outgassing and contamination during processing.
Solution Approach 2:
The overcoat layer acts as an intermediary barrier between the metal-containing photoresist and the processing environment. It prevents direct contact and outgassing of metal atoms while allowing the underlying photoresist to perform its patterning function, thus mediating between the need for precise patterning and the need to prevent contamination.
2Volume of moving object
If photoresist layer thickness is reduced to enable smaller device sizes, then device miniaturization is achieved, but process window becomes tighter and manufacturing becomes more difficult
Solution Approach 1:
The photoresist system uses composite materials combining a metal-containing photoresist with an overcoat layer. This composite structure enables thinner overall photoresist profiles for smaller devices while the overcoat provides additional processing margin and robustness, effectively widening the process window despite reduced dimensions.
3Device complexity
If conventional photoresist formation method is used, then process simplicity is maintained, but solvent residue and contamination occur
Solution Approach 1:
The photoresist formation process changes the parameter of solvent content by using solvent-free or low-solvent photoresist formulations. This parameter change eliminates solvent residue contamination while maintaining coating effectiveness, and the overcoat layer further prevents any potential outgassing issues.
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 enhances the throughput and reduces contamination, enabling more precise and reliable pattern formation for smaller semiconductor features, maintaining the march towards smaller device sizes while preventing metal contamination and improving lithography performance.
Implementation Method 1
The photoresist layer is selectively exposed to actinic radiation through the protective layer to form a latent pattern in the photoresist layer
Implementation Method 2
A protective layer is formed over a metal-containing photoresist layer on a substrate... to prevent outgassing and contamination
Implementation Method 3
The latent pattern is developed by applying a developer to the selectively exposed photoresist layer to form a pattern
Data Source
AI summary
A method of manufacturing a semiconductor device includes forming a photoresist layer over a substrate, including combining a first precursor and a second precursor in a vapor state to form a photoresist material, and depositing the photoresist material over the substrate. A protective layer is formed over the photoresist layer. The photoresist layer is selectively exposed to actinic radiation through the protective layer to form a latent pattern in the photoresist layer. The protective layer is removed, and the latent pattern is developed by applying a developer to the selectively exposed photoresist layer to form a pattern.