Integrated Filter for Lithography Coating Film Defect Reduction
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Solution Overview
Problem
The miniaturization of semiconductor device patterns leads to increased aspect ratios in photoresist films, causing processing failures due to reduced film thickness and the generation of coating defects in lithography films, which result in pattern defects and electrical faults in semiconductor devices.
Innovation Solution
A method involving the use of a spin coating device with an integrated filter that reduces eluting material to 3 mg or less per filter, achieved through circulative cleaning with an organic solvent, to form coating films with significantly reduced defects, suitable for resist upper layer, silicon-containing under layer, and organic under layer films.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the thickness of the photoresist film is reduced to maintain proper aspect ratio during miniaturization, then the aspect ratio of the photoresist pattern is kept within proper range, but processing failure of substrate occurs due to lack of durability to dry-etching
Solution Approach 1:
The patent divides the protective function into multiple layers: an organic underlayer film (first underlayer) and a silicon-containing underlayer film (second underlayer). This segmentation allows each layer to provide specific functions - the organic layer provides adhesion and basic protection, while the silicon-containing layer provides enhanced etch resistance, collectively solving the durability problem without requiring excessive thickness in a single layer
Solution Approach 2:
The patent uses composite material structure by combining organic polymer materials with silicon-containing materials in a multilayer configuration. This composite approach leverages the advantages of both material types - the organic material provides flexibility and adhesion, while the silicon-containing material provides hard protective function against dry-etching, resolving the contradiction between thin film requirement and etch durability
2Productivity
If spin coating is performed using a conventional filter, then coating film is formed efficiently, but coating defects are generated due to eluting material from the filter
Solution Approach 1:
The patent changes the critical parameter of filter eluting material content from conventional levels to 3 mg or less per filter. This parameter change is achieved through improved filter manufacturing processes and selection, directly reducing coating defects while maintaining the spin coating process efficiency, thus resolving the contradiction between productivity and manufacturing precision
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 approach effectively minimizes coating defects, enhancing the production yield of semiconductor devices by ensuring reliable pattern transfer during dry-etching processes, especially in multilayer resist methods for fine pitches like 40 nm or less.
Implementation Method 1
performing spin coating of a composition for forming a coating film for a lithography onto a substrate for producing a semiconductor device by using a spin coating device
Implementation Method 2
an integrated filter in which a filtration membrane and a housing are integrated
Implementation Method 3
heating the substrate for producing a semiconductor device coated with the composition for forming a coating film for a lithography; thereby forming a coating film
Data Source
AI summary
The present invention provides a method for forming a coating film for a lithography, comprising the steps of: performing spin coating of a composition for forming a coating film for a lithography onto a substrate for producing a semiconductor device by using a spin coating device provided with an integrated filter in which a filtration membrane and a housing are integrated; and heating the substrate coated with the composition for forming a coating film for a lithography; thereby forming a coating film for a lithography on the substrate, wherein the integrated filter is a filter in which eluting material is in at amount of 3 mg or less per a filter, the eluting material being extracted by circulating an organic solvent at a rate of 10 ml/min for 24 hours. This method enables to form a coating film for a lithography with its coating defects extremely reduced.