Sulfide-Bonded Organosilane Underlayer for Lithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The development of a resist underlayer film for semiconductor device production is hindered by the need for a material that prevents intermixing with the resist and offers a higher dry etching rate than the resist itself, while also serving as a hard mask and bottom anti-reflective coating, particularly with the increasing use of shorter wavelength active rays in lithography.
Innovation Solution
A resist underlayer film forming composition containing hydrolyzable organosilanes with sulfur atom-containing groups, their hydrolysis products, and hydrolysis-condensation products, which form a polysiloxane structure with a sulfur bond, enhancing dry etching resistance and etching rates when used in conjunction with specific etching gases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a hard mask containing metal elements such as silicon and titanium is used as an underlayer film, then the reflection preventing effect is achieved, but the removal rate by dry etching becomes highly dependent on gas type and requires careful selection to avoid excessive photoresist erosion
Solution Approach 1:
The patent combines multiple functions into a single underlayer film material. The silane compound with sulfide bond simultaneously provides reflection prevention, hard mask functionality, and controlled etching characteristics, eliminating the need for separate hard mask layers and reducing process complexity while maintaining effective reflection prevention
Solution Approach 2:
The underlayer film forming composition is designed to perform multiple functions: it acts as a bottom anti-reflective coating, a hard mask, and an etching rate control layer. This multi-functional material simplifies the overall lithography process by consolidating several required functions into one application layer
2Ease of manufacture
If the resist and hard mask have largely different components, then the hard mask can be removed by dry etching with appropriate gas selection, but the film thickness of the photoresist may decrease significantly
Solution Approach 1:
The patent modifies the chemical composition parameters of the underlayer film by incorporating specific silane compounds with sulfide bonds. This composition adjustment enables selective etching behavior where the underlayer film can be removed at controlled rates by dry etching while maintaining photoresist film thickness within acceptable tolerances
Solution Approach 2:
The underlayer film is formed from a composite chemical structure combining silicon, sulfur, and organic groups in specific ratios. This composite material provides both the hard mask properties needed for pattern transfer and the controlled etching characteristics that prevent excessive photoresist erosion during removal processes
3Adaptability or versatility
If a novel material for resist underlayer film is developed, then diverse characteristics such as reflection prevention and etching control can be achieved, but the material composition becomes more complex
Solution Approach 1:
The patent introduces local chemical functionality through sulfide bonds within the silane compound structure. This localized functional group provides specific interactions with etching gases and reflection control properties without requiring complex bulk material composition, achieving diverse characteristics through targeted molecular design
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 composition enables the formation of a resist underlayer film that functions as a hard mask and bottom anti-reflective coating, preventing intermixing with the resist and achieving a higher dry etching rate than the resist, thereby facilitating the production of semiconductor devices with improved pattern transfer and substrate processing.
Implementation Method 1
containing a hydrolyzable organosilane of Formula (1), a hydrolysis product thereof, or a hydrolysis-condensation product
Implementation Method 2
containing a hydrolyzable organosilane of Formula (1), a hydrolysis product thereof, or a hydrolysis-condensation product
Data Source
AI summary
There is provided a resist underlayer film forming composition for lithography for forming a resist underlayer film capable of being used as a hard mask; and a forming method of a resist pattern using the underlayer film forming composition for lithography. A resist underlayer film forming composition for lithography comprising: as a silicon atom-containing compound, a hydrolyzable organosilane containing a sulfur atom-containing group, a hydrolysis product thereof, or a hydrolysis-condensation product thereof, wherein in the whole silicon atom-containing compound, the ratio of a sulfur atom to a silicon atom is less than 5% by mole. The hydrolyzable organosilane is preferably a compound of Formula (1): [R1aSi(R2)3-a]bR3 wherein R3 has a partial structure of Formula (2): R4—S—R5.