Substrate Processing Method for Semiconductor Mask Reinforcement
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Solution Overview
Problem
The challenge in semiconductor manufacturing is forming finer circuit patterns with small-sized openings while maintaining etching resistance, as highly transparent mask layers with low hardness tend to collapse during the scaling-down process, leading to a trade-off between pattern fidelity and etching resistance, especially for line widths of 10 nm or less and high aspect ratios.
Innovation Solution
A substrate processing method involving molecular layer deposition (MLD) to form a reinforcement film on the organic film, which simultaneously trims the line width of the organic film's opening pattern, using a deposition/trimming apparatus that generates plasma to oxidize silicon-containing gases into a silicon oxide film, reinforcing the mask layer and reducing the line width.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a highly transparent material is employed to improve pattern transfer fidelity, then the pattern fidelity is improved, but the mask layer strength is deteriorated causing pattern collapse
Solution Approach 1:
The invention uses a composite structure consisting of an organic film (photoresist) and an inorganic reinforcement film (silicon oxide). The organic film provides pattern definition and transparency for faithful pattern transfer, while the inorganic reinforcement film deposited by MLD provides mechanical strength and etching resistance. This composite approach resolves the contradiction by combining materials with complementary properties.
Solution Approach 2:
The reinforcement film is formed on the organic film before the etching process. By performing the MLD deposition in advance, the organic film is pre-reinforced with a hard, etching-resistant layer that prevents pattern collapse during subsequent processing, allowing the use of highly transparent but mechanically weak materials for pattern formation.
2Manufacturing precision
If the line width of the resist pattern is reduced to form finer patterns, then the circuit pattern fineness is improved, but the pattern collapse occurs due to insufficient reinforcement
Solution Approach 1:
The composite structure of organic film plus inorganic reinforcement film enables the formation of ultra-fine lines (10 nm or less) by providing mechanical support to the thin organic film. The reinforcement film prevents collapse of high-aspect-ratio structures that would otherwise be impossible to form at such small dimensions.
Solution Approach 2:
The MLD process selectively reinforces the sidewalls and surface of the organic film where mechanical strength is needed, while maintaining the original pattern dimensions. The reinforcement is localized to where it is most needed (at the interfaces and surfaces subject to stress) rather than uniformly throughout the entire structure.
3Manufacturing precision
If the minimum feature dimension of the photoresist pattern is reduced to form small-sized openings, then the opening size is reduced, but the etching resistance is insufficient leading to pattern collapse
Solution Approach 1:
The invention creates a composite mask structure where the organic film defines the precise opening pattern while the inorganic reinforcement film provides the necessary etching resistance. This allows small-sized openings to be formed with high precision while maintaining structural integrity during the etching process.
Solution Approach 2:
The reinforcement film is deposited in advance before etching, pre-strengthening the mask structure to withstand the mechanical and chemical stresses of the etching process. This preliminary reinforcement enables the formation of small openings that would otherwise collapse under etching conditions.
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 method enables the formation of small-sized openings with improved etching resistance by reducing the line width of the photoresist film from approximately 30 nm to 7 nm without pattern collapse, reducing processing steps and minimizing defects, and allows for the formation of fine-width opening patterns suitable for advanced semiconductor devices.
Implementation Method 1
a deposition/trimming apparatus that generates plasma to oxidize silicon-containing gases into a silicon oxide film
Implementation Method 2
generates plasma to oxidize silicon-containing gases into a silicon oxide film
Implementation Method 3
forming a reinforcement film on a surface of the organic film by molecular layer deposition (MLD)
Implementation Method 4
at the same time, trimming a line width of a line portion of the organic film constituting an opening pattern
Data Source
AI summary
A method for processing a substrate including a processing target layer and an organic film, include: a deposition/trimming process of forming a reinforcement film on a surface of the organic film and, at the same time, trimming a line width of a line portion of the organic film constituting an opening pattern. The deposition/trimming process includes an adsorption process for allowing a silicon-containing gas to be adsorbed onto the surface of the organic film and an oxidation process in which the line width of the organic film is trimmed while the adsorbed silicon-containing gas is converted into a silicon oxide film. A monovalent aminosilane is employed as the silicon-containing gas.