Segmented Gas Supply Mechanism for Uniform Plasma Processing

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Solution Overview

Problem

Conventional plasma processing apparatuses with inductively coupled plasma (ICP) face challenges in achieving uniform processing on semiconductor wafers due to limited gas discharge areas, which restricts the control over processing gas supply and leads to non-uniform processing states.

Innovation Solution

A plasma processing apparatus with a gas supply mechanism featuring a layered body of dielectric plates and groove-shaped gas channels under a dielectric window, allowing horizontal gas supply from multiple ports, preventing electric discharge, and enabling uniform gas distribution across the wafer surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a large structure for introducing gas to above the substrate is used, then gas supply capability is improved, but the substrate processing state becomes non-uniform due to blocking

Engineering Contradiction:

Improvegas supply capabilityVSAvoidprocessing uniformity

Core Design Contradiction:

Quantity of substanceVSManufacturing precision

Solution Approach 1:

The gas supply structure is segmented into multiple small openings distributed across the upper cover, replacing a single large gas introduction structure. This segmentation allows gas to be supplied to multiple locations simultaneously without blocking the substrate, thereby maintaining processing uniformity while improving overall gas supply capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The gas supply approach transitions from a vertical gas introduction path (from above) to a horizontal gas supply path (from the side edges of openings). This dimensional change allows gas to reach the substrate without requiring a large overhead structure that would cause blocking, thus resolving the contradiction between gas supply capability and processing uniformity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Quantity of substance

If a gas diffusion space is installed between the substrate and the high frequency coil, then gas distribution is improved, but electric discharge occurs in this space

Engineering Contradiction:

Improvegas distributionVSAvoidelectric discharge

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

A dielectric material is introduced as an intermediary between the gas supply path and the high frequency coil. The dielectric material allows electric field penetration for plasma generation while preventing electric discharge in the gas diffusion space. This enables gas distribution improvement without the harmful effect of electric discharge.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If gas discharge area is limited to central and outer peripheral areas, then electric discharge prevention is achieved, but processing uniformity control is restricted

Engineering Contradiction:

Improveelectric discharge preventionVSAvoidprocessing uniformity control

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The gas discharge area is segmented into multiple small openings distributed across the entire upper cover surface, including central, intermediate, and peripheral regions. This segmentation allows gas to be discharged uniformly across all areas without creating large continuous discharge zones, thereby maintaining electric discharge prevention while enabling comprehensive processing uniformity control.

Inventive Principle:

Principle #1Segmentation

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 configuration improves processing uniformity on the wafer surface by allowing gas supply to any position, reducing the risk of electric discharge, and maintaining a stable plasma state for uniform etching processes.

Implementation Method 1

a plasma processing apparatus using inductively coupled plasma (ICP) as an apparatus for performing a process

Methodology Applied

Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Implementation Method 2

an upper cover installed to cover a top opening of the processing chamber and having a dielectric window

Methodology Applied

Scientific EffectDielectric property: Dielectric

Data Source

PatentUS8674607B2Plasma processing apparatus and processing gas supply structure thereof

Publication Date: 2014.03.18 TOKYO ELECTRON LTD

AI summary

There is provided a plasma processing apparatus for generating inductively coupled plasma in a processing chamber and performing a process on a substrate accommodated in the processing chamber. The plasma processing apparatus includes an upper cover installed to cover a top opening of the processing chamber and having a dielectric window; a high frequency coil installed above the dielectric window at an outer side of the processing chamber; a gas supply mechanism supported by the upper cover and installed under the dielectric window. Here, the gas supply mechanism includes a layered body including plates having through holes. Further, the gas supply mechanism is configured to supply a processing gas into the processing chamber in a horizontal direction via groove-shaped gas channels installed between the plates or between the plate and the dielectric window, and end portions of the groove-shaped gas channels are opened to edges of the through holes.