Electrostatic Chuck Pixelated Magnetic Field Plasma Uniformity

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Solution Overview

Problem

Conventional electrostatic chucks in plasma processing chambers face challenges in achieving uniform temperature and plasma density control due to non-uniformities caused by auxiliary hardware, leading to hot or cold spots, which affect etch processes and plasma uniformity.

Innovation Solution

Incorporating a plurality of electromagnets into the electrostatic chuck to provide a variable pixelated magnetic field, allowing for independent control of magnetic field strength and polarity, enabling fine-tuning of plasma density and uniformity at the wafer level, with localized control down to the millimeter scale.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional thermal control methods are used with long heat transfer fluid loops, then heating and cooling power is provided, but temperature control response time is slow

Engineering Contradiction:

Improvetemperature control response timeVSAvoidheat transfer fluid loop length

Core Design Contradiction:

TemperatureVSLength of moving object

Solution Approach 1:

The patent segments the magnetic field control into multiple independently controllable electromagnets arranged in an array, allowing localized and rapid magnetic field adjustments without requiring long fluid loops. This segmentation enables fast response times by eliminating the thermal inertia associated with large-volume fluid circulation systems.

Inventive Principle:

Principle #1Segmentation

2Temperature

If point-of-use thermal systems are used to reduce fluid loop lengths, then temperature control response time improves, but power load capability is limited by physical space constraints

Engineering Contradiction:

Improvetemperature control response timeVSAvoidpower load capability

Core Design Contradiction:

TemperatureVSPower

Solution Approach 1:

The patent replaces the mechanical thermal control system (heat transfer fluid loops) with an electromagnetic field system. The electromagnets generate magnetic fields that directly interact with the plasma, providing both temperature control and plasma density modulation without the physical space constraints and power limitations of thermal systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Quantity of substance

If temperature-based control is used, then plasma density can be influenced, but optimal plasma density tunability is not achieved

Engineering Contradiction:

Improveplasma density tunabilityVSAvoidplasma density control flexibility

Core Design Contradiction:

Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic control of plasma density through independently adjustable electromagnets that can rapidly change magnetic field strength and distribution. This dynamic electromagnetic control provides superior adaptability and versatility compared to static temperature-based control, allowing real-time optimization of plasma density across different processing conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the physical parameter from temperature control to magnetic field control. By adjusting magnetic field strength, distribution, and configuration through the electromagnet array, the system achieves broader and more precise plasma density tunability than thermal methods alone.

Inventive Principle:

Principle #35Parameter changes

4Quantity of substance

If auxiliary hardware is added to electrostatic chucks for control, then plasma density control is enabled, but non-uniformities cause hot or cold spots

Engineering Contradiction:

Improveplasma density controlVSAvoidtemperature uniformity

Core Design Contradiction:

Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent applies local quality control by arranging electromagnets in a pixelated array where each electromagnet can be independently controlled. This allows localized magnetic field adjustments to compensate for hot or cold spots, creating uniform plasma density across the substrate surface while maintaining the ability to perform localized process optimization.

Inventive Principle:

Principle #3Local quality

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 pixelated magnetic field arrangement enhances plasma density uniformity and etch rate control, allowing for precise tuning of etch processes on a die-by-die basis, improving the overall efficiency and accuracy of semiconductor processing.

Implementation Method 1

A plurality of electromagnets is disposed in the base, the plurality of electromagnets configured to provide pixelated magnetic field tuning capability for the ESC

Methodology Applied

Scientific EffectElectromagnetic field generation: Electromagnet

Data Source

PatentUS10790180B2Electrostatic chuck with variable pixelated magnetic field

Publication Date: 2020.09.29 APPLIED MATERIALS INC

AI summary

Electrostatic chucks with variable pixelated magnetic field are described. For example, an electrostatic chuck (ESC) includes a ceramic plate having a front surface and a back surface, the front surface for supporting a wafer or substrate. A base is coupled to the back surface of the ceramic plate. A plurality of electromagnets is disposed in the base, the plurality of electromagnets configured to provide pixelated magnetic field tuning capability for the ESC.