Photosensitive Resin Mask for Fine Hole and Groove Etching
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Solution Overview
Problem
Existing etching methods struggle to form holes with small diameters or grooves with narrow widths in semiconductor substrates using an etchant.
Innovation Solution
A photosensitive resin composition comprising a novolak resin, a photosensitizer, and a solvent is used to form a patterned cured product that acts as a mask with excellent etching resistance, allowing for the formation of small-diameter holes and narrow-width grooves in semiconductor substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional photosensitive resin composition is used to form a mask, then the mask can be formed with standard resolution, but the mask cannot maintain good etching resistance for long etching times required to form small-diameter holes or narrow-width grooves
Solution Approach 1:
The patent changes the chemical composition parameters of the photosensitive resin by incorporating specific compounds: a novolak resin (A) with phenolic hydroxyl groups, a photosensitizer (B), and crucially, a sulfur-containing compound (C) with specific molecular structure (formula 1). This compositional parameter change enables the cured product to maintain both fine pattern resolution and high etching resistance during prolonged etching processes for forming holes with diameters of 10 μm or less.
Solution Approach 2:
The patent creates a composite photosensitive resin composition by combining multiple functional components: novolak resin (A) for base structure and etching resistance, photosensitizer (B) for pattern formation, and sulfur-containing compound (C) for enhanced etching resistance. The synergistic interaction of these composite materials produces a cured mask that maintains structural integrity and resistance properties during long etching times required for small-feature fabrication.
2Manufacturing precision
If the etching time is extended to form small-diameter holes or narrow-width grooves, then the desired fine features can be formed, but the mask peels off from the substrate
Solution Approach 1:
The patent modifies the adhesion parameters of the mask system by incorporating the sulfur-containing compound (C) which forms strong chemical bonds with the substrate during curing. This parameter change in chemical bonding strength enables the mask to withstand the mechanical stresses and chemical attacks during extended etching times without peeling, while still achieving the required fine groove widths of 10 μm or less.
3Manufacturing precision
If a mask with fine transfer pattern is formed to achieve small hole diameters or narrow groove widths, then high manufacturing precision is achieved, but the etching resistance of the mask deteriorates
Solution Approach 1:
The patent applies local quality by creating a mask composition where different components serve specialized functions: the novolak resin (A) provides the structural framework for fine pattern transfer, while the sulfur-containing compound (C) locally enhances etching resistance at the mask-substrate interface. This localized functional differentiation allows the mask to simultaneously achieve fine pattern dimensions and maintain high etching resistance throughout the etching process.
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 enables the formation of holes with diameters of 10 um or less and grooves with widths of 10 um or less in semiconductor substrates, maintaining the pattern shape and preventing mask peeling during long etching times.
Implementation Method 1
a photosensitive resin composition comprising a resin (A), a photosensitizer (B), and a solvent (S)
Data Source
Figure 1A~1C
AI summary
To provide an etching method capable of forming a hole having a small diameter or a groove having a narrow width in a substrate, using an etchant, and a photosensitive resin composition for use in the etching method. An etching method, comprising: a coating step of forming a coating film by applying a photosensitive resin composition to a substrate, an exposure step of position-selectively exposing the coating film, a developing step of developing a coating film after exposure to expose a part of the substrate and obtain a patterned cured product, an etching step of etching the substrate to form a hole or groove in the substrate, with the etching being performed in the presence of a noble metal catalyst, using the patterned cured product as a mask and an aqueous solution including a corrosive agent and an oxidizing agent as an etchant, and a stripping step of stripping a patterned cured product after the etching step, from the substrate, wherein the photosensitive-resin composition comprises a resin (A), a photosensitizer (B), and a solvent (S), and wherein the resin (A) is a novolak resin.