Seed Layer Thickness Gradient for Substrate Feature Filling

Solution Overview

Problem

Conventional seed layer deposition processes in integrated circuit fabrication result in uneven thickness distribution within substrate features, leading to material buildup on corners and partial or complete closure of openings, preventing subsequent material filling.

Innovation Solution

A method involving the deposition of a seed layer with controlled thickness on substrate features, where the thickness is greater on the lower sidewall portion near the bottom than on the upper sidewall portion near the opening, followed by etching to remove excess material from the upper corners, creating an inwardly sloped profile to prevent closure and allow complete filling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional seed layer deposition is performed, then the seed layer covers the substrate features, but the thickness is greater on sidewalls proximate the opening than at the bottom, causing material buildup on corners and closure of openings

Engineering Contradiction:

Improveseed layer thickness uniformityVSAvoidmaterial buildup on corners

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by creating a non-uniform seed layer thickness distribution where the thickness varies along the sidewalls of the substrate features. Specifically, the seed layer is deposited with greater thickness on lower portions of sidewalls and lesser thickness on upper portions proximate the openings, which prevents material buildup on corners while ensuring adequate coverage at the bottom of features

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs preliminary action by performing an etch process on the deposited seed layer to remove excess material from upper sidewall portions and corner regions before subsequent material deposition. This preliminary removal of material prevents the harmful buildup that would otherwise occur during later processing steps

Inventive Principle:

Principle #10Preliminary action

2Reliability

If conventional seed layer deposition is performed, then the seed layer is deposited on substrate features, but openings are partially or fully closed, preventing material filling

Engineering Contradiction:

Improvefeature filling completenessVSAvoidopening closure

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by creating a non-uniform seed layer thickness distribution where the thickness varies along the sidewalls of the substrate features. Specifically, the seed layer is deposited with greater thickness on lower portions of sidewalls and lesser thickness on upper portions proximate the openings, which prevents material buildup on corners while ensuring adequate coverage at the bottom of features

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs preliminary action by performing an etch process on the deposited seed layer to remove excess material from upper sidewall portions and corner regions before subsequent material deposition. This preliminary removal of material prevents the harmful buildup that would otherwise occur during later processing steps

Inventive Principle:

Principle #10Preliminary action

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 ensures that substrate features are filled completely without void formation, as the seed layer thickness gradient facilitates uniform material deposition from the bottom to the top, preventing premature closure and ensuring effective layer formation.

Implementation Method 1

depositing a seed layer within the one or more features

Methodology Applied

Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Implementation Method 2

depositing a seed layer within the one or more features

Methodology Applied

Scientific EffectChemical Vapour Deposition: Chemical Vapour Deposition

Implementation Method 3

etching the seed layer to remove at least a portion of the seed layer proximate an opening of the feature

Methodology Applied

Scientific EffectPlasma Etching: Plasma

Data Source

PatentUS8993434B2Methods for forming layers on a substrate

Publication Date: 2015.03.31 APPLIED MATERIALS INC

AI summary

Methods for forming layers on a substrate having one or more features formed therein are provided herein. In some embodiments, a method for forming layers on a substrate having one or more features formed therein may include depositing a seed layer within the one or more features; and etching the seed layer to remove at least a portion of the seed layer proximate an opening of the feature such that the seed layer comprises a first thickness disposed on a lower portion of a sidewall of the feature proximate a bottom of the feature and a second thickness disposed on an upper portion of the sidewall proximate the opening of the feature and wherein the first thickness is greater than the second thickness.