Sacrificial Sublimation Filling for Semiconductor Feature Collapse

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Solution Overview

Problem

During semiconductor processing, high aspect ratio features are prone to collapse due to capillary forces from residual solvent after wet cleaning, leading to defects and potential device failure.

Innovation Solution

Forming a sacrificial material in the openings between features, which displaces the solvent and can be removed via sublimation, thereby preventing feature collapse.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wet cleaning is performed to remove residue, then cleaning effectiveness is improved, but capillary forces from residual solvent cause feature collapse

Engineering Contradiction:

Improvecleaning effectivenessVSAvoidfeature structural integrity

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

A sacrificial material is introduced as an intermediary substance that occupies the openings between features during drying. This sacrificial material acts as a mediator that prevents capillary forces from acting directly on the features, thereby eliminating the mechanism of feature collapse while allowing wet cleaning to proceed effectively

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The sacrificial material is deposited in advance before the drying step occurs. By preliminarily filling the openings with sacrificial material, the structure is prepared to resist capillary forces before they can cause damage during the subsequent drying process

Inventive Principle:

Principle #10Preliminary action

2Stability of the object's composition

If sacrificial material is deposited in openings to prevent collapse, then feature stability is improved, but process complexity increases

Engineering Contradiction:

Improvefeature stabilityVSAvoidprocessing steps

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The sacrificial material undergoes phase transition from solid to gas through sublimation, allowing it to be removed without leaving residue. This phase change mechanism provides a clean removal process that integrates seamlessly into existing semiconductor manufacturing workflows, minimizing added complexity

Inventive Principle:

Principle #36Phase transitions

Solution Approach 2:

The mechanical removal process is replaced by a thermal field-based sublimation process. Instead of using mechanical means to remove the sacrificial material, thermal energy is applied to induce sublimation, which simplifies the removal mechanism and reduces process complexity

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

The sacrificial material effectively reduces the likelihood of feature collapse during processing, maintaining structural integrity and preventing defects in semiconductor devices.

Implementation Method 1

removing the sacrificial material via sublimation by exposing the sacrificial material to sub-atmospheric pressure

Methodology Applied

Scientific EffectSublimation: Sublimation

Data Source

PatentUS12322585B2Sublimation in forming a semiconductor

Publication Date: 2025.06.03 MICRON TECHNOLOGY INC

AI summary

The present disclosure includes apparatuses and methods related to sublimation in forming a semiconductor. In an example, a method may include forming a sacrificial material in an opening of a structure, wherein the sacrificial material displaces a solvent used in a wet clean operation and removing the sacrificial material via sublimation by exposing the sacrificial material to sub-atmospheric pressure.