Multiple Trigger Photoresist Composition for Semiconductor Resolution
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Solution Overview
Problem
Current photoresist technologies face challenges in achieving finer resolution, reducing line broadening, and improving exposure latitude due to issues like acid migration and line edge roughness, especially when manufacturing smaller semiconductor devices.
Innovation Solution
A multiple trigger negative-working photoresist composition comprising polymers or oligomers with crosslinkable functionalities attached to acid labile protecting groups, combined with an acid activated crosslinker and a photoacid generator, which undergo a two-step reaction process upon exposure to actinic radiation, reducing acid migration and enhancing crosslinking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional photoresist materials and processes are used, then manufacturing process is simple, but resolution and line edge roughness deteriorate
Solution Approach 1:
The patent divides the crosslinking process into two distinct stages: first, acid-catalyzed crosslinking during post-exposure bake to form initial crosslinks and trap acid; second, moisture-triggered crosslinking during development to complete the crosslinking network. This segmentation prevents acid migration by confining acid activity to specific time windows, thereby improving resolution while maintaining process feasibility
Solution Approach 2:
The patent applies preliminary acid-catalyzed crosslinking during the post-exposure bake step before the actual development process. This preliminary action creates a partial crosslinked network that restrains acid migration and defines pattern boundaries early, leading to reduced line edge roughness and improved resolution in subsequent steps
2Speed
If photoacid generator is used to catalyze crosslinking, then crosslinking speed increases, but acid migration causes line broadening
Solution Approach 1:
The patent introduces a dual-crosslinking mechanism where the first crosslinking stage acts as an intermediary step. The initial acid-catalyzed crosslinks serve as a mediator that slows down the overall crosslinking process, preventing rapid acid migration while still achieving sufficient crosslinking density to define pattern edges before development
Solution Approach 2:
The patent implements periodic crosslinking action with two distinct phases: an initial acid-catalyzed phase during post-exposure bake, followed by a moisture-triggered phase during development. This periodic action controls the timing and location of crosslinking events, preventing continuous acid migration and improving line edge definition
3Manufacturing precision
If shorter wavelength actinic rays are used, then resolution improves, but sensitivity and exposure latitude deteriorate
Solution Approach 1:
The patent changes the chemical parameters of the resist system by introducing a dual-crosslinking mechanism with different triggering conditions (acid vs. moisture). This parameter change allows the resist to respond effectively to shorter wavelength radiation while maintaining exposure latitude through the two-stage process that accumulates crosslinks progressively rather than requiring a single high-energy exposure event
4Productivity
If heating step is applied to enhance crosslinking, then crosslinking efficiency improves, but acid migration increases
Solution Approach 1:
The patent converts the potentially harmful effect of heat-induced acid migration into a beneficial outcome by designing the first crosslinking stage to occur rapidly during post-exposure bake. The heat accelerates this initial crosslinking, and the resulting crosslinked network then serves to trap and immobilize acid, preventing further migration during subsequent heating steps in the process
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 significantly improves resolution, reduces resist blur, and enhances exposure latitude, allowing for the creation of finer patterns and more precise semiconductor features.
Implementation Method 1
The PAG releases a proton in the presence of actinic radiation (light or e-beam). This proton then reacts with the polymer to cause it to lose the functional group thus deprotecting the hydroxy group.
Implementation Method 2
a condensation reaction with a crosslinking agent occurs to form a crosslinked polymer network
Implementation Method 3
heating the coated substrate to form a substantially dried coating
Data Source
AI summary
The present disclosure relates to novel multiple trigger negative working photoresist compositions and processes. The processes involve removing acid-labile protecting groups from crosslinking functionalities in a first step and crosslinking the crosslinking functionality with an acid sensitive crosslinker in a second step. The incorporation of a multiple trigger pathway in the resist catalytic chain increases the chemical gradient in areas receiving a low dose of irradiation, effectively acting as a built in dose depend quencher-analog and thus enhancing chemical gradient and thus resolution, resolution blur and exposure latitude. The photoresist compositions and the methods are ideal for fine pattern processing using, for example, ultraviolet radiation, beyond extreme ultraviolet radiation, extreme ultraviolet radiation, X-rays and charged particle rays.