Polymer Resist Composition for Low-Dose Lithography
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Solution Overview
Problem
Chemically amplified photoresists face challenges such as decreased pattern uniformity and increased surface roughness due to acid diffusion, especially in finer semiconductor processes, and require high light exposure doses for property changes.
Innovation Solution
A polymer with specific repeating units that change solubility upon light exposure even at low doses, used in a resist composition with an organic solvent, allowing for pattern formation through exposure and development.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If chemically amplified photoresist is used to enable patterning through acid-base reaction, then pattern formation is achieved, but acid diffusion to unexposed regions causes decreased pattern uniformity and increased surface roughness
Solution Approach 1:
The patent extracts and removes the photoacid generator component from the resist system entirely. Instead of using a chemically amplified photoresist that generates acid upon exposure, the invention employs a direct photoreaction mechanism where the polymer itself undergoes structural changes when exposed to light, eliminating the harmful acid diffusion effect while maintaining pattern formation capability
Solution Approach 2:
The patent introduces a photoreactive group as an intermediary component within the polymer structure. This photoreactive group acts as a mediator that directly absorbs light energy and triggers structural changes in the polymer backbone or side chains, replacing the indirect acid-mediated chemical amplification pathway and preventing acid diffusion to unexposed regions
2Manufacturing precision
If chemically amplified photoresist is used for patterning, then solubility change is achieved through acid reaction, but control of acid diffusion becomes difficult in finer semiconductor processes
Solution Approach 1:
The patent removes the photoacid generator and chemical amplification mechanism from the system. The resist now relies on direct photoreaction of the polymer containing photoreactive groups, which simplifies the process mechanism and eliminates the need to control acid diffusion, thereby reducing process control complexity while maintaining fine pattern capability
Solution Approach 2:
The patent replaces the chemical mechanism (acid-base reaction) with a direct photophysical mechanism. The polymer undergoes direct structural transformation upon light absorption through photoreactive groups, substituting the complex chemical amplification pathway with a simpler, more controllable direct photoreaction process
3Manufacturing precision
If new resist materials are developed to overcome chemically amplified photoresist limits, then pattern formation capability is improved, but light exposure dose required remains high
Solution Approach 1:
The patent modifies the molecular structure parameters of the polymer by incorporating photoreactive groups with high photoreactivity. This structural parameter change enables the material to achieve the desired solubility transformation at lower light exposure doses, improving energy efficiency while maintaining pattern formation capability
Solution Approach 2:
The patent creates a composite polymer structure combining a base polymer backbone with photoreactive functional groups attached as side chains or incorporated into the main chain. This composite structure leverages the photoreactivity of specific functional groups (such as o-nitrobenzyl, orthoester, or oxime ether groups) to achieve efficient light absorption and rapid structural change at reduced exposure doses
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
The polymer enables efficient pattern formation with increased resolution and reduced exposure dose, while minimizing uniformity issues and surface roughness, and has improved storage stability and resistance to oxygen and moisture.
Implementation Method 1
X11 may be a photo-degradable group
Data Source
AI summary
Provided are a polymer including a first repeating unit represented by Formula 1 below and a second repeating unit represented by Formula 2 below, a resist composition including the same, and a method of forming a pattern using the same.In Formulae 1 and 2, L11 to L13, L21 to L24, a11 to a13, a21 to a24, A11, A21, X11, R11, R12, R21 to R23, b12, b22, b23, p11 and p21 are as described above in the specification.