Phenolic Monomer Polymer for Semiconductor Underlayer Film
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the semiconductor industry, the miniaturization of devices requires thinner photoresist layers, which are prone to collapse and have difficulty etching target layers due to lack of etching resistance, necessitating an under-layer with high thermal resistance and low reflection to prevent contamination and equipment damage during high-temperature processing.
Innovation Solution
A phenolic monomer and polymer with high transparency, thermal resistance, low reflection, and low shrinkage are developed, capable of self-crosslinking at high temperatures, forming a spin-on-carbon hard mask that functions as both an organic bottom anti-reflective coating and provides excellent etching resistance and gap-filling performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the photoresist layer is made thinner to prevent collapse and enable miniaturization, then pattern stability is improved, but etching resistance deteriorates
Solution Approach 1:
An organic under-layer is introduced as an intermediary between the thin photoresist layer and the target layer. This under-layer serves as a hard mask that provides the necessary etching resistance, allowing the photoresist to remain thin for pattern stability while the under-layer handles the etching protection function.
Solution Approach 2:
The structure is segmented into multiple functional layers: the photoresist layer for patterning and the organic under-layer for etching resistance. This segmentation allows each layer to be optimized independently - the photoresist can be made thin for pattern stability while the under-layer provides sufficient thickness and material properties for etching protection.
2Strength
If an inorganic under-layer is used to provide high etching resistance, then etching resistance is improved, but particle contamination and facility investment increase
Solution Approach 1:
The patent uses an organic under-layer that can be applied via spin-coating as a disposable, single-use layer. This replaces expensive, complex inorganic CVD facilities with a simpler, lower-cost organic material application process that achieves the same protective function without generating particle contamination.
Solution Approach 2:
The mechanical/physical CVD deposition process for inorganic layers is replaced with a chemical solution-based spin-coating process for organic layers. This substitution eliminates the need for expensive vacuum facilities and reduces particle generation associated with inorganic material deposition.
3Ease of manufacture
If the resist under-layer is exposed to high temperature (240-500°C) to form the inorganic hard mask, then the inorganic layer formation is enabled, but the organic under-layer decomposes and contaminates equipment
Solution Approach 1:
The patent modifies the thermal stability parameter of the under-layer by using specially designed organic materials with high glass transition temperatures and thermal resistance. This allows the under-layer to withstand the 240-500°C processing temperatures required for inorganic layer formation without decomposing and contaminating equipment.
Solution Approach 2:
The patent employs composite organic materials with enhanced thermal stability, combining multiple functional groups and molecular structures that provide both the necessary etching resistance and high-temperature stability. This composite approach enables the under-layer to maintain structural integrity at high temperatures.
4Volume of moving object
If the photoresist layer is made thinner for miniaturization, then device size reduction is achieved, but light reflection control becomes more difficult
Solution Approach 1:
The organic under-layer acts as an intermediary layer between the photoresist and substrate that provides optical properties for light reflection control. This under-layer functions as a bottom anti-reflective coating, absorbing or scattering reflected light and preventing standing wave formation, which is particularly important when using thin photoresist layers for 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 phenolic monomer and polymer solution enables effective patterning with high thermal stability, low out-gassing, and improved etching resistance, maintaining smoothness on patterned wafers with height differences, while functioning as a high-temperature SOC material.
Implementation Method 1
capable of self-crosslinking at high temperatures
Implementation Method 2
A phenolic monomer and polymer with high transparency, thermal resistance, low reflection, and low shrinkage are developed
Implementation Method 3
forming a spin-on-carbon hard mask
Data Source
AI summary
A phenolic monomer used in the lithographic process for semiconductor fabrication, a polymer for preparing a resist under-layer comprising the same, and a resist under-layer composition comprising the same, are disclosed. The phenolic monomer is represented by the formula 1 of the specification, in Formula 1, R1, R2, R3, and R4 are independently a hydrogen atom, or a straight-chain, branched, monocyclic or polycyclic saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms with or without a hetero atom; A is a monocyclic or polycyclic aromatic hydrocarbon group having 4 to 20 carbon atoms; X is an oxygen atom (O) or a sulfur atom (S); and Y is a single bond, a methylene group (—CH2-), an oxygen atom (O), a sulfur atom (S), an amino group (—NH—), or two isolated hydrogen atoms, wherein A, R1, R2, R3, and R4 can be substituted with a straight-chain, branched, monocyclic or polycyclic saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms with or without a hetero atom; and either R1 and R2 or R3 and R4 are independently linked to each other to form a ring.