Multi-layer Film for Semiconductor Patterning
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Solution Overview
Problem
Current multi-layer resist processes face challenges in achieving high dimensional accuracy and reducing substrate reflectance for fine pattern formation in semiconductor manufacturing, particularly due to insufficient dry etching resistance and thermal stability of under layer films, leading to increased reflection and processing costs.
Innovation Solution
A method involving the formation of a multi-layer film using an under layer film with a resin containing a fluorene structure, a titanium or zirconium oxide film, a hydrocarbon film, and a silicon oxide film, applied via spin coating, which reduces reflectance and enhances etching resistance through optimized film thickness and refractive index values, allowing for high-temperature processing without decomposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a hydrocarbon under layer film and silicon-containing intermediate film are formed by spin coating to flatten the film surface, then the film surface can be flattened by a simple process, but the dry etching resistance is insufficient for double-patterning or digging deep holes or grooves
Solution Approach 1:
The patent applies composite materials by combining a spin-coated under layer film with a metal oxide hard mask film (formed by sputtering or CVD). This composite structure integrates the flattening capability of spin coating with the high dry etching resistance of metal oxide films, allowing the under layer film to provide surface flattening while the metal oxide layer provides the necessary etching resistance for deep hole formation and double-patterning processes
2Reliability
If a metal hard mask is formed by sputtering or CVD to achieve high dry etching resistance, then the etching resistance is improved, but the film surface cannot flatten unevenness of the base material and requires additional CMP processing
Solution Approach 1:
The patent segments the film formation process into two distinct functional layers: an under layer film formed by spin coating that handles surface flattening, and a metal oxide hard mask film formed by sputtering or CVD that provides dry etching resistance. This segmentation allows each layer to perform its specific function optimally without requiring additional CMP processing steps
3Ease of manufacture
If the baking temperature is raised to 250°C or higher to form a metal oxide film by spin coating, then the metal oxide film can be formed, but the usual hydrocarbon under layer film is thermally decomposed
Solution Approach 1:
The patent uses the under layer film as an intermediary that protects the substrate during high-temperature metal oxide film formation. The under layer film is specifically designed with high heat resistance to withstand the 250°C or higher baking temperature required for metal oxide film formation without decomposing, thereby enabling the metal oxide film formation process while maintaining the integrity of the underlying structure
4Stability of the object's composition
If a novolac resin of fluorene bisnaphthol or aldehyde condensates of carbazole or fluorenone are used as under layer film material to achieve high heat resistance, then the thermal stability is improved, but the material selection and process complexity increase
Solution Approach 1:
The patent applies parameter changes by modifying the chemical structure of the under layer film material to incorporate fluorene structures with specific repeating units that provide high heat resistance. By changing the molecular parameters (introducing fluorene rings and specific functional groups), the material achieves the required thermal stability for withstanding 250°C or higher baking temperatures while maintaining ease of manufacture through spin coating processes
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 achieves reduced substrate reflectance and improved dimensional accuracy in dry etching, enabling efficient pattern transfer with high etching resistance and cost-effective processing by using spin coating, which is more economical than sputtering or CVD methods.
Implementation Method 1
forming an under layer film on the substrate by applying an under layer film material containing a resin having a repeating unit represented by the general formula (1) or (2) in which a fluorene structure is contained, and curing the same by heat treatment
Implementation Method 2
forming an under layer film on the substrate by applying an under layer film material
Data Source
AI summary
A method for forming multi-layer film on substrate, which includes steps (1) forming under layer film on substrate by applying under layer film material containing resin having repeating unit represented by the general formula (1) or (2) in which fluorene structure is contained, and curing the same by heat treatment, (2) forming metal oxide film on the under layer film by applying metal oxide film material selected from titanium oxide film material, zirconium oxide film material, and hafnium oxide film material, (3) forming hydrocarbon film on metal oxide film by applying hydrocarbon film material, and (4) forming silicon oxide film on the hydrocarbon film by applying silicon oxide film material. There can be provided a method for forming multi-layer film that can reduce reflectance, and useful for a patterning process with high dimensional accuracy of dry etching.