Magnetoresistive Element Etching Coercive Force Restoration

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The magnetic characteristics of magnetoresistive effect elements are compromised during etching processes, particularly when reactive ion etching is used, leading to a need for techniques that can suppress this reduction.

Innovation Solution

A method involving etching of multilayer films with a heating process that adjusts the ambient conditions of the workpiece, either during or after etching, to restore the coercive force of the magnetoresistive effect elements, using a plasma processing apparatus to control temperature and gas environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If reactive ion etching is used to process the magnetoresistive effect element, then the etching process can be performed effectively, but the magnetic characteristics of the magnetoresistive effect element are reduced

Engineering Contradiction:

Improveetching efficiencyVSAvoidmagnetic characteristics

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies parameter changes by heating the workpiece to a specific temperature range (100°C to 300°C) after etching to restore magnetic characteristics. This thermal parameter change reverses the damage caused by etching without compromising the etching efficiency itself, thus resolving the contradiction between productivity and reliability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the harmful effect of etching (reduction in magnetic characteristics) into a beneficial outcome by applying a subsequent heating process. The heating process exploits the temperature-dependent magnetic properties to restore and even enhance the magnetic characteristics that were degraded during etching, effectively turning the etching damage into an opportunity for property optimization.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If heating is applied after etching to restore coercive force, then magnetic characteristics are improved, but additional process time and complexity are required

Engineering Contradiction:

Improvecoercive forceVSAvoidprocess complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the heating process with the existing etching process by performing heating in the same vacuum chamber and using the same heating apparatus that is already part of the etching system. This integration combines two processes into one operational sequence, reducing overall process complexity while achieving the desired restoration of coercive force.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The heating process uses the vacuum chamber and heating capabilities that are already inherent to the etching system. Rather than requiring a completely separate processing system, the etching apparatus itself provides the heating function, making the system self-sufficient and avoiding additional external equipment complexity.

Inventive Principle:

Principle #25Self-service

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 method effectively restores the coercive force of magnetoresistive effect elements, ensuring the magnetic characteristics are preserved and maintained, even after etching, by controlling the ambient conditions and temperature within specific ranges.

Implementation Method 1

heating the workpiece after the etching or during the etching, wherein the heating includes heating the workpiece while adjusting an ambient condition of the workpiece

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

restores the coercive force of the magnetoresistive effect element by heating the workpiece while adjusting the ambient condition

Methodology Applied

Scientific EffectMagnetic properties restoration through thermal treatment: Heat Treatment

Implementation Method 3

using a plasma processing apparatus to control temperature and gas environments

Methodology Applied

Scientific EffectPlasma: Plasma

Data Source

PatentUS11171286B2Method of processing workpiece

Publication Date: 2021.11.09 TOKYO ELECTRON LTD

AI summary

There is provided a method of processing a workpiece for manufacturing a magnetoresistive effect element, the workpiece including a first multilayer film and a second multilayer film, the first multilayer film including a first magnetic layer, a second magnetic layer and a tunnel barrier layer formed between the first magnetic layer and the second magnetic layer, and the second multilayer film constituting a pinning layer in the magnetoresistive effect element. The method includes etching the first multilayer film and the second multilayer film, and heating the workpiece after the etching or during the etching. The heating includes heating the workpiece while adjusting an ambient condition of the workpiece.