Electromagnet-Controlled Plasma Chamber for Uniform Ion Distribution

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Solution Overview

Problem

Existing plasma processing apparatuses lack effective methods to control the distribution of ions and radicals reaching a workpiece, which affects the precision and consistency of plasma processing.

Innovation Solution

A plasma processing apparatus equipped with an upper and sidewall electromagnet unit, comprising concentrically arranged annular electromagnets, and a controller to adjust current supply to these electromagnets, allowing precise control over plasma electron density distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional plasma processing apparatus are used, then plasma processing can be performed, but the distribution of ions and radicals reaching the workpiece cannot be effectively controlled

Engineering Contradiction:

Improveprecision of plasma processingVSAvoidcontrol capability over ion and radical distribution

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The electromagnet system is divided into multiple independent coil units (first through fourth coil units) arranged at different positions and orientations around the plasma generation region. Each coil unit can be independently controlled to adjust magnetic field distribution, enabling precise control over ion and radical transport to different areas of the workpiece surface.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements position-dependent magnetic field control where each coil unit generates magnetic fields with specific characteristics tailored to its location. This allows different regions of the plasma process chamber to have optimized magnetic field conditions for controlling ion and radical distribution, achieving uniform processing quality across the workpiece surface.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If multiple electromagnet units are added to control plasma distribution, then ion and radical distribution control is improved, but device complexity increases

Engineering Contradiction:

Improveuniformity of plasma processingVSAvoidcomplexity of electromagnet system

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The multiple coil units serve multiple functions: they generate magnetic fields for plasma confinement, control ion and radical distribution patterns, and enable adjustment of plasma density uniformity. This multi-functionality reduces the need for separate systems for each function, managing overall device complexity while achieving precise plasma control.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The coil units are configured to generate magnetic fields that create equipotential conditions for plasma electron density distribution across the workpiece surface. By coordinating the magnetic fields from multiple coils, the system achieves uniform plasma conditions without requiring complex independent control of each region.

Inventive Principle:

Principle #12Equipotentiality

3Manufacturing precision

If magnetic field is used to control plasma electron density, then ion and radical distribution is improved, but energy consumption increases

Engineering Contradiction:

Improvecontrol over plasma electron density distributionVSAvoidenergy consumption of electromagnet system

Core Design Contradiction:

Manufacturing precisionVSUse of energy by stationary object

Solution Approach 1:

The coil units are configured to generate time-varying magnetic fields that dynamically control plasma electron density distribution. By using alternating current through the coils, the system achieves effective plasma control with reduced average power consumption compared to static magnetic fields, while maintaining precision in ion and radical distribution control.

Inventive Principle:

Principle #15Dynamics

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

Enables precise control over the distribution of ions and radicals, improving the precision and consistency of plasma processing on workpieces.

Implementation Method 1

an electromagnet assembly configured to generate a magnetic field in the plasma process chamber

Methodology Applied

Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

a plasma processing apparatus includes: a plasma process chamber; a substrate support disposed within the plasma process chamber; an antenna disposed above the plasma process chamber

Methodology Applied

Scientific EffectPlasma: Plasma

Data Source

PatentUS20250218744A1Plasma processing apparatus

Publication Date: 2025.07.03 TOKYO ELECTRON LTD

AI summary

A plasma processing apparatus includes: a plasma process chamber; a substrate support disposed within the plasma process chamber; an antenna disposed above the plasma process chamber; a source RF signal generator configured to generate a source RF signal; a bias signal generator configured to generate a bias signal; an upper electromagnet unit including a plurality of upper annular electromagnets arranged concentrically; a sidewall electromagnet unit including a plurality of sidewall annular electromagnets; an electromagnet excitation circuit configured to supply a current to at least one of the plurality of upper annular electromagnets or the plurality of sidewall annular electromagnets; and a controller configured to adjust the current supplied to at least one of the plurality of upper annular electromagnets or the plurality of sidewall annular electromagnets to control a plasma electron density distribution in the plasma process chamber.