Organic Bottom Anti-Reflective Coating for Lithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current organic bottom anti-reflective coatings face challenges in minimizing reflectivity and achieving high etch selectivity and etching rates, especially when used with shorter wavelength radiation in semiconductor lithography processes, leading to poor pattern profiles and uniformity.
Innovation Solution
A polymer-based organic bottom anti-reflective coating composition is developed, incorporating specific chemical structures that enhance absorption properties and etch selectivity, with a weight average molecular weight of 1,000 to 30,000 g/mol, and a formulation including 1 to 50 wt% polymer and 50 to 99 wt% organic solvent, which forms a coating with a refractive index of 1.91 to 2.0 and extinction coefficient of 0.20 to 0.30 at 193 nm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If inorganic bottom anti-reflective coating is used to optimize reflectance, then reflectance is reduced, but the coating is difficult to remove in subsequent processes and causes footing phenomenon
Solution Approach 1:
The patent uses organic bottom anti-reflective coating materials composed of multiple functional components including polymer resins with specific molecular weight ranges (1,000-30,000 g/mol), light absorbers, and etchable functional groups. This composite organic material system achieves both low reflectance through light absorption and easy removability through chemical etching processes, resolving the contradiction between reflectance optimization and ease of removal that plagues inorganic coatings.
2Manufacturing precision
If exposure light wavelength is shortened to achieve ultrafine patterns below 30 nm, then pattern resolution is improved, but light interference effect from reflective light increases
Solution Approach 1:
The patent introduces an organic bottom anti-reflective coating as an intermediary layer between the photoresist and the substrate. This intermediate layer contains light absorbers that specifically target short wavelength exposure light (157 nm, 193 nm, 248 nm), absorbing the harmful reflective light before it can cause interference effects. This mediator layer enables ultrafine pattern formation by eliminating the light interference problem that would otherwise prevent such high resolution work.
3Object-affected harmful factors
If organic bottom anti-reflective coating is used to absorb exposure light, then light absorption property is excellent, but etching rate in dry etching process is lower compared to inorganic coating
Solution Approach 1:
The patent optimizes the molecular weight parameters of the polymer resin components to fall within 1,000-30,000 g/mol, and adjusts the concentration of etchable functional groups in the organic coating formulation. These parameter changes enhance the chemical reactivity of the organic bottom anti-reflective coating with dry etching plasma, significantly improving the etching rate while preserving the excellent light absorption properties that enable it to function as an effective bottom anti-reflective coating.
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-based coating effectively reduces reflection, achieves high etching rates, and ensures excellent etch selectivity, enabling the formation of good pattern shapes and ultrafine patterns even with shorter wavelength radiation, such as 157 nm, 193 nm, and 248 nm, during semiconductor manufacturing.
Implementation Method 1
the organic bottom anti-reflective coating absorbs light passing through a photoresist film
Data Source
AI summary
Provided are a polymer for an organic bottom anti-reflective coating and a bottom anti-reflective coating composition containing the same. More specifically, provided are a polymer for an organic bottom anti-reflective coating capable of relieving reflection of exposure light and irradiation light on a substrate of a photoresist layer applied on the substrate in a lithographic process of manufacturing a semiconductor device, and a bottom anti-reflective coating composition containing the same.