Carbon Gapfill Densification Using LFRF Plasma Treatment

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Solution Overview

Problem

Conventional carbon gapfill processes struggle to uniformly fill high aspect ratio features in semiconductor devices, leading to issues such as film density, etch selectivity, film shrinkage, delamination, and the formation of voids or seams, which negatively impact device performance and fabrication costs.

Innovation Solution

The use of low frequency radio frequency (LFRF) plasma treatment during and/or after carbon gapfill deposition, combined with dual-frequency biased plasma treatment, to densify the carbon material and improve film quality, reducing voids and seams in high aspect ratio structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional carbon gapfill deposition is used to fill high aspect ratio features, then the gapfill operation can be performed, but the film density decreases and voids or seams form

Engineering Contradiction:

Improvegapfill uniformityVSAvoidfilm density

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies low frequency radio frequency (LFRF) plasma treatment to change the physical and chemical parameters of the deposited carbon film. This treatment densifies the film by altering its microstructure, converting porous carbon to denser forms, and improving film quality without requiring changes to the deposition process itself

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The LFRF plasma treatment is performed as a preliminary densification step before subsequent processing operations. By densifying the carbon film in advance, the process prevents formation of voids and seams that would otherwise occur during later fabrication steps, ensuring film integrity throughout the manufacturing process

Inventive Principle:

Principle #10Preliminary action

2Productivity

If conventional carbon gapfill deposition is used, then the process can be completed, but film shrinkage and delamination occur

Engineering Contradiction:

Improvegapfill process completionVSAvoidfilm stability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The LFRF plasma treatment modifies the physical parameters of the carbon film, densifying it and improving its mechanical properties. This parameter change stabilizes the film composition, preventing shrinkage and delamination that would otherwise occur during subsequent processing

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies LFRF plasma treatment as a cushioning step that pre-stabilizes the carbon film before it undergoes subsequent processing operations. This preliminary treatment creates a more stable film structure that can withstand the stresses of later fabrication steps without shrinking or delaminating

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Length of moving object

If device features are reduced in size with higher aspect ratios, then device scaling is achieved, but gapfill performance decreases

Engineering Contradiction:

Improvefeature sizeVSAvoidgapfill quality

Core Design Contradiction:

Length of moving objectVSManufacturing precision

Solution Approach 1:

The LFRF plasma treatment changes the physical parameters of the deposited carbon material, densifying it and improving film quality. This parameter change compensates for the difficulties associated with filling high aspect ratio features, enabling successful gapfill even as device dimensions continue to scale down

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces reliance on mechanical deposition control with a plasma-based densification process. Instead of attempting to control film formation during deposition of high aspect ratio features, the process deposits carbon material and then uses LFRF plasma treatment to achieve the desired film quality, substituting a chemical/plasma process for mechanical control

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

This approach enables the formation of high-density carbon gapfill structures without sacrificing film quality, enhancing pattern fidelity and reducing fabrication costs by mitigating film shrinkage and delamination.

Implementation Method 1

exposing the semiconductor substrate to a low frequency radio frequency (LFRF) biased plasma treatment to densify the carbon material of the film deposited on the structure

Methodology Applied

Scientific EffectPlasma: Plasma

Implementation Method 2

exposing the semiconductor substrate to a low frequency radio frequency (LFRF) biased plasma treatment

Methodology Applied

Scientific EffectRadio frequency heating: Dielectric Heating

Data Source

PatentUS20250316476A1Densification of carbon gapfill using low frequency radio frequency (LFRF) treatment

Publication Date: 2025.10.09 APPLIED MATERIALS INC

AI summary

The present disclosure provides methods and apparatus that facilitate the formation of high-quality carbon gapfill structures and that address the issues related to conventional carbon gapfill methods. In certain embodiments, the carbon gapfill methods and apparatus described herein utilize a low frequency radio frequency (LFRF) biased plasma treatment to gapfill structures with high-quality and high-density carbon films.