Protective Polymer Layer for Small-Gap Semiconductor Patterning
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Solution Overview
Problem
As semiconductor devices shrink in size, the process windows for photolithographic processing become tighter, making it challenging to maintain the ability to scale down devices due to issues with gap-filling ability, wet etch resistance, and adhesion of etching masks in small gaps, particularly in forming metal-containing layers like work function metal layers in FinFETs.
Innovation Solution
A composition of cross-linkable polymers is used to form a protective layer as part of an etching mask, which includes polymers with specific molecular weights and functional groups to enhance gap-filling ability, wet etch resistance, and adhesion to metal-containing layers, along with a cross-linking process to create larger, more resistant grains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional photolithographic materials are used, then existing process capabilities are maintained, but gap-filling ability deteriorates in small gaps
Solution Approach 1:
The patent changes the chemical parameters of the photolithographic material by using a polymer with specific functional groups (carboxyl, hydroxyl, or amine groups) and controlled molecular weight (1,000-10,000 daltons). These parameter changes improve gap-filling ability while maintaining adhesion to metal-containing layers, effectively resolving the contradiction between manufacturing precision and process window adaptability.
Solution Approach 2:
The patent employs a composite material system consisting of a polymer backbone with specific functional groups attached. This composite structure combines the gap-filling properties of the polymer chain with the adhesion properties of the functional groups, achieving both improved gap-filling ability and maintained process window for photolithographic processing.
2Manufacturing precision
If etching mask materials are optimized for gap-filling, then adhesion to metal-containing layers deteriorates
Solution Approach 1:
The patent introduces functional groups (carboxyl, hydroxyl, or amine) as key parameters in the polymer structure. These functional groups provide strong adhesion to metal-containing layers through chemical interaction, while the polymer backbone maintains gap-filling ability. This parameter change resolves the contradiction between gap-filling and adhesion strength.
Solution Approach 2:
The patent applies local quality by having different parts of the polymer molecule serve different functions: the polymer backbone provides gap-filling capability while the terminal functional groups provide adhesion to metal layers. This differentiation of local properties within the single material resolves the contradiction between gap-filling and adhesion.
3Volume of moving object
If device size is reduced, then miniaturization is achieved, but wet etch resistance of etching masks deteriorates
Solution Approach 1:
The patent changes the chemical composition parameters of the etching mask material by incorporating polymers with specific functional groups and molecular weights. This compositional change enhances wet etch resistance even as device dimensions are reduced, allowing miniaturization while maintaining reliability of the etching process.
Solution Approach 2:
The patent uses a composite polymer material that combines the structural properties needed for small-gap filling with chemical properties (functional groups) that provide wet etch resistance. This composite approach allows the etching mask to maintain reliability during miniaturization.
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 solution provides a protective layer with improved gap-filling, wet etch resistance, and adhesion, enabling effective patterning and protection of metal-containing layers in semiconductor devices, even in small gaps, thus supporting the miniaturization of semiconductor devices.
Implementation Method 1
a cross-linking process to create larger, more resistant grains
Data Source
AI summary
A method of manufacturing a semiconductor device includes the following operations. A protective layer is formed over a substrate, in which the protective layer is formed by a composition including a polymer having a polymer backbone and end groups. The polymer backbone is formed by polymerizing a monomer composition including first monomers, and each of the first monomer independently has an aryl substituted with 1, 2, 3, 4, or 5 hydroxyl groups. The end groups include:or combinations thereof. A is a substituted or unsubstituted hydrocarbon group. B is a hydroxyl group, an alkyl group, or a fluoroalkyl group. A photoresist layer is formed over the protective layer. The photoresist layer is patterned.