Resist Underlayer Film Curing for Dry Etching Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The miniaturization of semiconductor patterns leads to reduced photoresist film thickness, resulting in lower resolution performance and increased aspect ratios, causing pattern collapse and inadequate dry etching resistance.
Innovation Solution
A method for forming a resist underlayer film using a composition containing an aromatic ring-containing resin without hydroxy groups or specific organic groups, followed by heat treatment and plasma irradiation to enhance dry etching resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the photoresist film is thinned to enable finer patterning, then the pattern width can be reduced, but the resolution performance is lowered and aspect ratio increases causing pattern collapse
Solution Approach 1:
The patent divides the resist system into multiple layers: an upper photoresist layer for pattern formation and a lower underlayer film for etching resistance. This segmentation allows each layer to be optimized independently - the upper layer for resolution and the lower layer for mechanical support and etching protection.
Solution Approach 2:
The underlayer film acts as an intermediary between the upper photoresist layer and the substrate. It provides etching resistance and mechanical support to the thin upper layer, preventing pattern collapse while allowing the upper layer to maintain fine pattern dimensions.
2Length of moving object
If the photoresist film is thinned for finer patterning, then smaller features can be formed, but the aspect ratio increases leading to pattern collapse
Solution Approach 1:
By segmenting the resist structure into upper and lower layers, the patent distributes the functional requirements - the upper layer provides pattern definition while the lower layer provides mechanical stability, preventing collapse of high aspect ratio patterns.
Solution Approach 2:
The patent uses composite material structure combining an organic photoresist upper layer with a plasma-polymerized underlayer. This composite provides both the photo sensitivity needed for patterning and the mechanical/chemical resistance needed for stable high aspect ratio structures.
3Manufacturing precision
If a resin with low light absorption is used to improve resolution, then exposure sensitivity increases, but dry etching resistance decreases
Solution Approach 1:
The patent assigns different functional requirements to different layers: the upper photoresist layer uses resins optimized for light absorption and exposure sensitivity, while the lower underlayer film provides dry etching resistance through plasma polymerization, resolving the contradiction between resolution and etching resistance.
Solution Approach 2:
The underlayer film serves as an intermediary that provides dry etching resistance without interfering with the optical properties of the upper photoresist layer, allowing each layer to be optimized for its specific function.
4Ease of manufacture
If conventional organic underlayer film materials are used, then the process is simple, but dry etching resistance is insufficient
Solution Approach 1:
The patent changes the physical and chemical parameters of the underlayer film through plasma treatment. By controlling plasma power, gas composition, and treatment time, the underlayer achieves high dry etching resistance while maintaining process simplicity through a single additional treatment step.
Solution Approach 2:
The patent creates a composite structure where the organic underlayer material is modified by plasma polymerization to form a crosslinked network with enhanced dry etching resistance, combining the ease of organic material deposition with the resistance properties of plasma-polymerized films.
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 method produces a resist underlayer film with improved dry etching resistance and precise pattern formation, even on substrates with complex structures, enabling finer patterning in semiconductor device manufacturing.
Implementation Method 1
forming a resist underlayer film by curing the underlayer-film-precursor film by plasma irradiation
Implementation Method 2
subjecting the coating film to heat treatment at a temperature of 100° C. or higher and 800° C. or lower for 10 seconds to 7,200 seconds to cure the coating film
Data Source
AI summary
The present invention is a method for forming a resist underlayer film on a substrate, the method including the steps of: (i) forming an underlayer-film-precursor film by coating a substrate with a composition for forming a resist underlayer film, containing (A) a polymer and an organic solvent, to obtain a coating film and subjecting the coating film to heat treatment at a temperature of 100° C. or higher and 800° C. or lower for 10 seconds to 7,200 seconds to cure the coating film; and (ii) forming a resist underlayer film by curing the underlayer-film-precursor film by plasma irradiation, where the polymer (A) is an aromatic ring-containing resin containing no hydroxy groups or organic groups represented by the following general formulae (1) in a repeating unit contained in the polymer, where “p” represents 0 or 1, and “*” represents an attachment point. This can provide a method for forming a resist underlayer film according to which it is possible to form a resist underlayer film that exhibits excellent dry etching resistance.