Sealed Air Gap Plasma Removal for Consistent Semiconductor Cavities

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Solution Overview

Problem

Existing semiconductor device manufacturing methods face challenges in completely removing residues from air gaps, leading to variations in gap volume due to incomplete decomposition of organic materials during thermal processing.

Innovation Solution

A method involving embedding a sacrificial material in a substrate recess, covering it with a sealing film, and using plasma to decompose and remove residues through the film, with optional heating to facilitate thermal decomposition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If thermal decomposition is used to remove sacrificial material, then the organic material is decomposed and removed, but residues remain in the air gap due to incomplete decomposition

Engineering Contradiction:

Improveair gap volume consistencyVSAvoidresidue amount

Core Design Contradiction:

Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent changes the processing parameters by introducing plasma treatment as a subsequent step after thermal decomposition. The plasma processing modifies the chemical and physical state of the sacrificial material removal process, enabling complete elimination of residues that thermal decomposition alone cannot remove, thereby achieving consistent air gap volume without residues

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite processing approach combining thermal decomposition and plasma treatment. The sealing film serves as a composite structure that allows plasma species to penetrate and decompose trapped sacrificial material while maintaining the sealed environment, achieving complete material removal without compromising the air gap structure

Inventive Principle:

Principle #40Composite materials

2Loss of substance

If plasma is used to decompose sacrificial material through the sealing film, then residues are removed, but the processing complexity increases

Engineering Contradiction:

Improveresidue amountVSAvoidprocess steps

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

The sealing film serves multiple functions: it seals the recess during sacrificial material deposition, maintains the sealed environment during thermal decomposition, and allows plasma species to penetrate for residue removal. This multi-functionality eliminates the need for separate structures for each process step, reducing overall system complexity despite adding plasma processing

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent maintains continuous processing by performing thermal decomposition and plasma treatment in sequence without breaking the sealed environment. The sacrificial material is first thermally decomposed, then plasma is introduced to remove residues, creating a continuous material removal process that minimizes additional handling and setup steps

Inventive Principle:

Principle #20Continuity of useful action

3Stability of the object's composition

If high temperature heating is applied to decompose organic material, then decomposition is enhanced, but substrate integrity may be compromised

Engineering Contradiction:

Improveorganic material decompositionVSAvoidsubstrate integrity

Core Design Contradiction:

Stability of the object's compositionVSStrength

Solution Approach 1:

The patent replaces purely thermal processing with plasma processing for the final residue removal step. Plasma provides chemical decomposition through reactive species rather than relying solely on thermal energy, enabling complete material removal at lower temperatures that protect the substrate from thermal damage while maintaining decomposition effectiveness

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Reduces residues in air gaps, ensuring consistent volume and minimizing variations, while maintaining substrate integrity by controlling thermal exposure.

Implementation Method 1

decomposing the sacrificial material in the recess by turning a processing gas into plasma outside the recess and supplying active species contained in the plasma to the sacrificial material via the sealing film

Methodology Applied

Scientific EffectPlasma: Plasma

Implementation Method 2

heating the substrate to a predetermined temperature to thermally decompose the organic material and desorbing the organic material below the silicon nitride film

Methodology Applied

Scientific EffectThermal decomposition: Pyrolysis

Implementation Method 3

desorbing the organic material below the silicon nitride film via the silicon nitride film

Methodology Applied

Scientific EffectDesorption: Desorption

Data Source

PatentUS20250210344A1Semiconductor device manufacturing method and semiconductor device manufacturing system

Publication Date: 2025.06.26 TOKYO ELECTRON LTD

AI summary

A semiconductor device manufacturing method includes: a) embedding a sacrificial material in a recess formed in a substrate; b) covering the recess in which the sacrificial material is embedded with a sealing film; and c) decomposing the sacrificial material in the recess by turning a processing gas into plasma outside the recess and supplying active species contained in the plasma to the sacrificial material via the sealing film, and removing the sacrificial material in the recess via the sealing film.