Inverted Pattern Formation Using Tin-Containing Materials

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Solution Overview

Problem

Current pattern formation methods using tin-containing photoresist films struggle with reducing pattern width and achieving high etching selectivity, particularly when using tin-containing materials, as they are typically negative resist films that are difficult to narrow and require specific reactive gases for removal.

Innovation Solution

A method involving forming a first pattern with a tin-containing material on a substrate, followed by filling the pattern with a second material and removing the first pattern to create an inverted pattern, using gases like hydrogen bromide to enhance etching selectivity without plasma, allowing for smaller pattern widths and increased material choices for the filling material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If tin-containing photoresist film is used for pattern formation, then etching selectivity is improved, but pattern width reduction becomes difficult

Engineering Contradiction:

Improveetching selectivityVSAvoidpattern width

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The patent inverts the conventional pattern formation approach by using a positive resist film instead of negative resist, allowing the pattern to be formed in the underlying film rather than the resist itself. This inversion enables simultaneous achievement of narrow pattern widths and high etching selectivity with tin-containing materials

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent segments the pattern formation process into distinct steps: forming the resist pattern, transferring it to the underlying film through etching, and then removing the resist. This segmentation allows the tin-containing material to serve its primary function of providing etching selectivity while the pattern width is controlled by the resist and transfer process

Inventive Principle:

Principle #1Segmentation

2Productivity

If plasma is used for removing tin-containing pattern, then removal efficiency is improved, but etching selectivity decreases

Engineering Contradiction:

Improveremoval efficiencyVSAvoidetching selectivity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent replaces the plasma-based removal process with a chemical wet etching process using selective etchants. This substitution maintains high removal efficiency while preserving etching selectivity, as the chemical process can be tuned to selectively remove tin-containing materials without affecting other film layers

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the removal mechanism from physical plasma etching to chemical wet etching, altering the process parameters to achieve both high removal efficiency and maintained selectivity. The chemical etchants are specifically selected to react with tin-containing materials at controlled rates

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If negative resist film is used, then tin-containing material can be utilized, but pattern width reduction is limited

Engineering Contradiction:

Improvematerial compatibilityVSAvoidpattern width

Core Design Contradiction:

Adaptability or versatilityVSLength of moving object

Solution Approach 1:

The patent inverts the resist type from negative to positive, fundamentally changing how the pattern is transferred. This allows tin-containing materials to be used in the underlying film while achieving narrow pattern widths through the positive resist's inherent ability to form fine features that are then transferred to the film

Inventive Principle:

Principle #13The other way round (Inversion)

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 method effectively inverts patterns from tin-containing materials to smaller widths, improving etching selectivity and material options for the filling portion, enabling the formation of precise patterns like contact holes with enhanced aspect ratios.

Implementation Method 1

removing the first pattern, wherein the first pattern is removed by using a hydrogen bromide gas

Methodology Applied

Scientific EffectEtching:

Data Source

PatentUS20230130385A1Method for forming a pattern

Publication Date: 2023.04.27 TOKYO ELECTRON LTD

AI summary

In one exemplary embodiment, a method for forming a pattern includes (a) forming, on a substrate, a first pattern having an opening and containing a first material, (b) forming a filling portion in the opening, the filling portion containing a second material different from the first material, and (c) removing the first pattern so that the filling portion remains as a second pattern inverted with respect to the first pattern. At least one of the first material or the second material contains tin.