Wet Etching Additive Control for Semiconductor Defect Suppression

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Solution Overview

Problem

The integration of two-dimensional semiconductor devices is limited by expensive processing equipment, and three-dimensional semiconductor devices face challenges in defect minimization during the wet etching process, particularly in controlling etch selectivity and suppressing abnormal oxide growth.

Innovation Solution

A method of wet etching that involves using a process bath with a primary etchant, a first additive to increase specific material concentration, and a second additive to suppress defects, with separate supply of these components to maintain optimal silicon concentration and prevent oxide growth, utilizing a controlled etching apparatus.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the concentration of specific material in the etchant is increased to improve etch selectivity, then etching precision is improved, but abnormal oxide growth occurs causing defects

Engineering Contradiction:

Improveetch selectivityVSAvoiddefect occurrence

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

A second additive is introduced as an intermediary substance that suppresses abnormal oxide growth while allowing the first additive to increase silicon concentration for improved etch selectivity. This mediator resolves the conflict between achieving high etch selectivity and preventing defect formation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the chemical parameters of the etchant by controlling the concentration of silicon through separate additives. By independently adjusting the silicon concentration and oxide growth suppression parameters, the system achieves optimal etch selectivity without causing abnormal oxide growth defects.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If processing equipment is upgraded to increase pattern fineness for higher integration, then manufacturing precision is improved, but device complexity and cost increase

Engineering Contradiction:

Improvepattern finenessVSAvoidprocessing equipment complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical processing equipment with a chemically-controlled wet etching system. By using precisely controlled chemical reactions with multiple additives to achieve pattern fineness, the need for expensive and complex lithography equipment is reduced, lowering device complexity while maintaining high manufacturing precision.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If the concentration of specific material in the etchant is increased to control etch selectivity, then etching precision is improved, but oxide growth occurs causing defects

Engineering Contradiction:

Improveetch selectivityVSAvoidabnormal oxide growth

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The second additive serves as a mediator that counteracts the harmful oxide growth effect caused by increased silicon concentration. It is supplied separately to specifically suppress oxide growth without interfering with the etch selectivity enhancement provided by the first additive.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful oxide growth effect is extracted and addressed separately from the etching process by introducing a dedicated second additive whose sole function is to suppress oxide growth, allowing the primary etching function to operate at optimal silicon concentration without side effects.

Inventive Principle:

Principle #2Taking out (Extraction)

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 controls etch selectivity and minimizes defects in the wet etching process, enabling efficient fabrication of semiconductor devices with reduced abnormal oxide growth and improved integration capabilities.

Implementation Method 1

selectively wet etching a portion of the stacked thin layers

Methodology Applied

Scientific EffectWet etching:

Implementation Method 2

the wet etching process may be performed using an etchant having an etch selectivity

Methodology Applied

Scientific EffectEtch selectivity:

Data Source

PatentUS10242880B2Method of wet etching and method of fabricating semiconductor device using the same

Publication Date: 2019.03.26 SAMSUNG ELECTRONICS CO LTD

AI summary

Disclosed are a method of wet etching and a method of fabricating a semiconductor device. The wet etching method includes providing a wafer in a process bath and an etchant is accommodated, supplying the process bath with a primary etchant to control a concentration of a specific material in the etchant, supplying the process bath with a first additive to increase the concentration of the specific material in the etchant, and supplying the process bath with a second additive to suppress a defect caused by an increase in the concentration of the specific material in the etchant. The etchant includes at least one, of the primary etchant, the first additive, and the second additive. The first additive and the second additive are separately supplied to the process bath.