Organic Film Composition for Semiconductor Patterning
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Solution Overview
Problem
Current multilayer resist methods for semiconductor manufacturing face challenges in forming high-aspect-ratio patterns without pattern twisting or curving, especially on substrates with steps, due to limitations in etching resistance and planarization, particularly when using amorphous carbon films or single-molecular compounds.
Innovation Solution
A composition comprising a polymer with a repeating unit of condensed aromatic rings and a thermal crosslinking group, combined with an organic solvent, which forms a film with high etching resistance and excellent twisting resistance, and can be applied using spin coating to achieve uniform thickness and precise pattern formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a CVD-C film is used as the underlayer film to improve etching resistance, then the pattern twisting and curving is suppressed, but the substrate steps cannot be filled and the photoresist film thickness becomes non-uniform
Solution Approach 1:
The patent changes the material parameters of the underlayer film from amorphous carbon (CVD-C) to a polymer with condensed aromatic rings and thermal crosslinking groups. This parameter change enables the material to simultaneously provide high etching resistance and filling capability for substrate steps, resolving the contradiction between pattern stability and film thickness uniformity
Solution Approach 2:
The patent uses a composite polymer structure combining condensed aromatic rings (for etching resistance) with thermal crosslinking groups (for filling and adhesion). This composite material approach allows the underlayer film to exhibit both high etching resistance and excellent filling properties, eliminating the need to choose between the two conflicting requirements
2Manufacturing precision
If a spin coating method is used to fill substrate steps and improve film uniformity, then the focus margin increases, but the etching resistance and twisting resistance decrease
Solution Approach 1:
The patent fundamentally changes the material composition parameters of the spin-coated underlayer film by incorporating polymers with condensed aromatic rings and thermal crosslinking groups. This parameter transformation enables the film to achieve both good filling properties (from spin coating) and high etching/twisting resistance (from the specialized polymer structure), resolving the contradiction between film uniformity and pattern stability
3Manufacturing precision
If the pattern aspect ratio is increased to achieve finer patterning, then the pattern collapse occurs due to surface tension, but the manufacturing precision improves
Solution Approach 1:
The patent applies preliminary thermal crosslinking to the underlayer film before the actual patterning process. This preliminary action strengthens the mechanical properties and structural integrity of the underlayer film, enabling it to support high-aspect-ratio patterns without collapse while maintaining the fine patterning capability. The crosslinked structure provides the necessary rigidity to prevent pattern collapse during development and etching
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 solution enables the formation of organic films with high etching resistance and twisting resistance, improving pattern fidelity and planarization on substrates with complex structures, while minimizing sublimation and outgassing, thus enhancing the precision and reliability of semiconductor manufacturing processes.
Implementation Method 1
the polymer containing a repeating unit shown by general formula (1A) as a partial structure... W1 represents any in general formula (1B)... R1 represents a monovalent organic group having 1 to 10 carbon atoms and an unsaturated bond
Implementation Method 2
there is an advantage that a step(s) of the uneven substrate can be filled into a flat state. Planarizing the substrate by using the underlayer film material
Data Source
Figure 1(A)~1(F)
Figure 2
AI summary
A composition for forming an organic film contains a polymer having a repeating unit shown by formula (1A) as a partial structure, and an organic solvent, where AR1 and AR2 represent a benzene ring or naphthalene ring optionally with a substituent; W1 represents any in formula (1B), and the polymer optionally contains two or more kinds of W1; W2 represents a divalent organic group having 1 to 80 carbon atoms; Ri represents a monovalent organic group having 1 to 10 carbon atoms and an unsaturated bond; and R2 represents a monovalent organic group having 6 to 20 carbon atoms and one or more aromatic rings. This invention provides: an organic film composition which enables excellent film formability, high etching resistance, and excellent twisting resistance without impairing the resin-derived carbon content, and which contains less outgassing-causing sublimation component; a patterning process using the composition; and a polymer suitable for the composition.