Partial Carbon Gapfill for HDP Topography Planarization

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Solution Overview

Problem

Conventional high-density plasma (HDP) deposition processes result in thick overburden on semiconductor device structures, leading to non-uniform device topography that negatively impacts performance and subsequent processing operations.

Innovation Solution

A method involving deposition of a carbon gapfill layer into trenches, followed by selective etching of the oxide layer and carbon gapfill layer using plasma-based etching, and subsequent chemical mechanical polishing (CMP) to planarize the substrate, reducing overburden thickness and improving topography.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If high-density plasma (HDP) deposition is used to fill trenches, then gapfilling capability is improved, but overburden is generated causing non-uniform topography

Engineering Contradiction:

Improvegapfilling capabilityVSAvoiddevice topography uniformity

Core Design Contradiction:

Manufacturing precisionVSShape

Solution Approach 1:

The patent segments the gapfilling process into multiple steps: initial HDP deposition to fill trenches, followed by selective removal of overburden through etch-back and CMP. This segmentation allows the process to achieve both complete trench filling and uniform final topography by treating different regions (trenches vs. overburden) differently at different stages.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary HDP deposition to completely fill trenches before addressing the overburden issue. By ensuring trenches are fully filled first, the process guarantees gapfilling capability is achieved, and then subsequent steps (etch-back and CMP) are used to remove the intentionally created overburden to restore uniformity.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If thicker oxide layers are deposited to ensure complete trench filling, then gapfilling reliability is improved, but subsequent CMP process time and cost increase

Engineering Contradiction:

Improvetrench filling completenessVSAvoidCMP process time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the deposition parameters by using HDP with controlled deposition rates and patterns, rather than simply increasing oxide layer thickness. This allows complete trench filling at moderate thickness levels, and the selective etch-back step then removes excess material, preventing excessive CMP time while ensuring reliable filling.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces a carbon gapfill layer as an intermediary material during the HDP process. This carbon layer facilitates complete trench filling by modifying deposition behavior, and is subsequently selectively removed through plasma etching, allowing reliable filling without requiring excessively thick oxide layers that would increase CMP time.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If conventional HDP deposition is used, then process simplicity is maintained, but extensive CMP is required to achieve uniformity

Engineering Contradiction:

Improveprocess simplicityVSAvoidCMP process time

Core Design Contradiction:

Device complexityVSLoss of time

Solution Approach 1:

The patent performs preliminary selective removal of overburden through plasma etching before the final CMP step. This preliminary action reduces the amount of material that needs to be removed during CMP, significantly reducing CMP time while maintaining process simplicity through the addition of only one selective etching step.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent modifies the HDP deposition parameters and introduces selective plasma etching to change the material removal characteristics. This allows the process to achieve uniform topography with reduced CMP time by pre-removing overburden, balancing process simplicity with time efficiency.

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 method achieves a more uniform device topography, enhancing device performance and reducing manufacturing costs by minimizing the need for extensive CMP processes.

Implementation Method 1

a material may be deposited via high-density plasma chemical vapor deposition (HDPCVD)

Methodology Applied

Scientific EffectChemical Vapour Deposition: Chemical Vapour Deposition

Implementation Method 2

etching, via a plasma-based etch process, the carbon gapfill layer

Methodology Applied

Scientific EffectPlasma: Plasma

Implementation Method 3

performing a chemical mechanical polishing (CMP) process to planarize the oxide layer

Methodology Applied

Scientific EffectChemical mechanical polishing:

Data Source

PatentUS20250313948A1High-density plasma (HDP) topography improvement with partial gapfill carbon

Publication Date: 2025.10.09 APPLIED MATERIALS INC

AI summary

Embodiments disclosed herein generally relate to high-density plasma (HDP) deposition and other gapfilling processes for semiconductor manufacturing. The process includes depositing a carbon gapfill layer into one or more trenches formed in an oxide layer of a semiconductor device structure, etching at least a portion of the oxide layer, etching, via a plasma-based etch process, the carbon gapfill layer, and performing a chemical mechanical polishing (CMP) process to planarize the oxide layer. Implementing such processes for HDP deposition and gapfilling results in various improvements in the manufacturing of semiconductor substrates.