Flowable Material Stop Layer for Semiconductor Planarization

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Solution Overview

Problem

The increasing complexity of manufacturing smaller semiconductor devices has led to difficulties in planarization, resulting in undesirable defects that can affect device performance and yield, as existing methods struggle to create a flat surface effectively.

Innovation Solution

A method involving the formation of a patterned material layer with regions of different heights, followed by the application of a flowable material layer that exposes and removes the higher region as a stop layer, reducing stress and preventing cracks during planarization, using techniques like etching and chemical mechanical polishing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional planarization methods are used on material layers with high step heights, then the manufacturing process can proceed, but defects such as cracks and poor planarization occur

Engineering Contradiction:

Improveplanarization qualityVSAvoiddevice yield

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The material layer is divided into multiple regions with different heights (first region with lower top surface, second region with higher top surface). This segmentation allows selective processing of different regions, enabling the protrusion in the second region to be removed separately before final planarization, thereby preventing defects while maintaining manufacturing precision.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A flowable material layer is formed in advance on the material layer before the final planarization process. This preliminary action serves as a protective layer that prevents cracks during planarization and as a stop layer that enables selective removal of the protrusion. The flowable material layer is removed after serving its protective and guiding functions.

Inventive Principle:

Principle #10Preliminary action

2Ease of manufacture

If the material layer has regions with different heights, then selective processing is enabled, but the manufacturing complexity increases

Engineering Contradiction:

Improveselective processing capabilityVSAvoidprocess steps

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The flowable material layer serves multiple functions: it acts as a protective layer preventing cracks during planarization, as a stop layer enabling selective removal of the protrusion, and as a temporary structure facilitating the manufacturing process. After serving these functions, it is removed. This multi-functionality reduces the need for multiple separate process steps.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The method utilizes changes in material properties and process parameters. The flowable material layer has specific etch selectivity relative to the material layer, allowing selective removal. The protrusion height and flowable material layer thickness are controlled within specific ranges to enable the selective etching process while maintaining process simplicity.

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

This approach effectively reduces step heights between material layers, enhancing the yield and reliability of semiconductor devices by minimizing defects and ensuring a flat surface for subsequent processes.

Implementation Method 1

removing the protrusion on the second region of the material layer with the flowable material layer as a stop layer

Methodology Applied

Scientific EffectEtching:

Implementation Method 2

planarizing the material layer

Methodology Applied

Scientific EffectChemical mechanical polishing:

Data Source

PatentUS10615046B2Methods of forming semiconductor devices with flowable material for better planarization method

Publication Date: 2020.04.07 WINBOND ELECTRONICS CORP

AI summary

A method of forming semiconductor devices includes providing a substrate with a patterned material layer formed thereon, forming a material layer on the patterned material layer, wherein the material layer has a first region with a lower top surface and a second region with a higher top surface, forming a flowable material layer on the material layer, wherein the flowable material layer exposes at least a portion of the second region of the material layer, removing the exposed portion of the second region of the material layer with the flowable material layer as a stop layer, removing the flowable material layer, and planarizing the material layer.