Composite Plasma Modulator for Etching Uniformity

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Solution Overview

Problem

Conventional dry etching techniques face challenges in maintaining uniformity across semiconductor wafers as structures become more complex and wafer sizes increase, leading to non-uniform plasma distribution and decreased manufacturing yield.

Innovation Solution

A composite plasma modulator is introduced, comprising a substrate with a first dielectric material and a modulating portion made of a second dielectric material, which is positioned between the plasma generator and the plasma zone to modulate plasma energy distribution, compensating for non-uniformities by adjusting the energy of plasma ions using different band gaps and dielectric constants.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional dry etching techniques are used, then the etching process can be performed, but etching uniformity across the wafer deteriorates due to plasma non-uniformity

Engineering Contradiction:

Improveetching uniformityVSAvoidplasma distribution uniformity

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies local quality by positioning dielectric blocks with different dielectric constants at specific locations within the plasma chamber. These blocks create localized modifications to the plasma field, allowing different regions of the wafer to receive tailored plasma conditions that compensate for geometry-induced non-uniformities, thereby improving overall etching uniformity

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent utilizes parameter changes by selecting dielectric materials with different dielectric constants and strategically positioning them to modify the plasma field distribution. By changing the local electrical parameters through these dielectric blocks, the plasma density and ion energy distribution are adjusted to achieve more uniform etching across the wafer surface

Inventive Principle:

Principle #35Parameter changes

2Productivity

If wafer size increases, then production capacity improves, but plasma uniformity deteriorates leading to decreased manufacturing yield

Engineering Contradiction:

Improveproduction capacityVSAvoidetching uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

For larger wafers, the patent employs multiple dielectric blocks positioned at different locations to create localized plasma field adjustments. This allows each region of the expanded wafer area to receive optimized plasma conditions, compensating for the increased difficulty of maintaining uniformity across larger surfaces

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite dielectric structures with different material properties (different dielectric constants) to create a distributed plasma control system. This composite approach allows tailored modification of the plasma field across different zones of large wafers, maintaining etching uniformity despite increased wafer size

Inventive Principle:

Principle #40Composite materials

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 modulator improves etching uniformity by reducing plasma ion energy in specific regions, thereby enhancing the consistency of etching processes and manufacturing yield by addressing local geometry-induced non-uniformities.

Implementation Method 1

Methodology Applied

Scientific EffectDielectric material properties (band gap and dielectric constant): Dielectric

Data Source

PatentUS11367591B2Composite plasma modulator for plasma chamber

Publication Date: 2022.06.21 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A plasma-processing apparatus includes a chamber, a plasma generator, and a composite plasma modulator. The chamber includes a plasma zone. The plasma generator is configured to generate a plasma in the plasma zone. The composite plasma modulator is configured to modulate the plasma. The composite plasma modulator includes a dielectric plate made of a first dielectric material and a first modulating portion made of a second dielectric material and coupled to the dielectric plate.