Metal Oxide Resist Underlayer for High Selectivity Etching

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Solution Overview

Problem

Conventional multilayer resist methods face challenges in achieving high etching selectivity and mild stripping conditions for semiconductor manufacturing, particularly in forming fine patterns with existing organic and silicon-containing films, which are prone to substrate damage and pattern collapse.

Innovation Solution

A composition for forming a metal oxide-containing film using hydrolysable metal compounds and aromatic compounds, which provides high etching selectivity and can be stripped under mild conditions, enhancing pattern adhesiveness and allowing for the formation of fine patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional organic and silicon-containing films are used in multilayer resist methods, then the process is simple to implement, but etching selectivity is insufficient and substrate damage occurs during stripping

Engineering Contradiction:
Improveetching selectivityVSAvoidsubstrate damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent uses a composite material consisting of a metal oxide-containing film (formed from hydrolysable metal compounds) combined with an organic resist film. This composite structure provides high etching selectivity between the metal oxide layer and underlying layers, while the organic resist provides pattern definition. The metal oxide film can be selectively stripped without damaging the substrate, resolving the contradiction between achieving high etching selectivity and preventing substrate damage.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the chemical composition parameters of the resist system by introducing metal oxide-containing compounds with specific properties (hydrolyzable groups, controlled decomposition temperatures). These parameter changes enable the film to exhibit high etching selectivity under specific etching conditions and allow for mild stripping conditions that prevent substrate damage while maintaining pattern integrity.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If conventional multilayer resist methods are used, then the manufacturing process is straightforward, but pattern adhesiveness is insufficient leading to pattern collapse

Engineering Contradiction:
Improvepattern adhesivenessVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent employs a composite resist system where a metal oxide-containing film is formed over an organic resist film. The metal oxide layer provides enhanced pattern adhesiveness and structural support, preventing pattern collapse during subsequent processing steps. The organic resist layer maintains ease of patterning and manufacturing. This composite approach improves pattern adhesiveness without significantly complicating the manufacturing process.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The metal oxide-containing film is formed in advance as an underlayer before the organic resist patterning step. This preliminary action creates a stable, adhesive foundation that supports the subsequent resist pattern, preventing collapse during etching and other processing steps while maintaining a straightforward manufacturing sequence.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If existing resist films are used, then the coating process is simple, but the film cannot be stripped under mild conditions resulting in residue formation

Engineering Contradiction:
Improvestripping conditionsVSAvoidresidue formation
Core Design Contradiction:
Ease of operationVSLoss of substance

Solution Approach 1:

The patent modifies the chemical parameters of the resist system by incorporating metal oxide-containing compounds with hydrolysable groups and controlled thermal stability. These parameter changes enable the film to be stripped under mild conditions (such as aqueous ammonia or hydrochloric acid solutions at elevated temperatures) without leaving residues, while the organic resist component can be removed by conventional means. This resolves the contradiction between achieving mild stripping conditions and preventing residue formation.

Inventive Principle:
Principle #35Parameter changes

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 metal oxide-containing film exhibits improved etching selectivity and adhesiveness, enabling precise pattern formation on semiconductor substrates without damaging the substrate, and can be stripped using aqueous ammonia or hydrochloric acid solutions, preventing residue formation.

Implementation Method 1

component (A), a metal oxide-containing compound A1 obtained by hydrolysis and/or condensation of one or more kinds of hydrolysable metal compounds

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 2

an aromatic compound shown by the following general formula (B-1), the compound generating a hydroxyl group by thermal and/or an acid

Methodology Applied
Scientific EffectThermal decomposition: Thermolysis

Data Source

PatentUS9377690B2Compositon for forming metal oxide-containing film and patterning process
Publication Date: 2016.06.28 SHIN ETSU CHEMICAL CO LTD

AI summary

The invention provides a composition for forming a metal oxide-containing film comprising, as a component (A), a metal oxide-containing compound A1 obtained by hydrolysis and/or condensation of one or more kinds of hydrolysable metal compounds shown by the following general formula (A-1), as a component (B), an aromatic compound shown by the following general formula (B-1), the compound generating a hydroxyl group by thermal and/or an acid. There can be provided a composition for a resist lower layer film, which has high etching selectivity, capable of subjecting to stripping under mild conditions than the conventional process, has excellent pattern adhesiveness, and fine pattern formation can be performed.