Etching Apparatus Using Dual-Angle Ion Beam to Remove Magnetic Redeposition
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Solution Overview
Problem
The redeposition of magnetic material during the patterning of magnetic layers in devices such as magnetic memory (MRAM) degrades the characteristics of these devices, as existing etching methods fail to effectively remove redeposition, leading to inefficiencies and electrical short failures.
Innovation Solution
An etching apparatus and method that utilizes a combination of low and high angle ion beam etchings to pattern magnetic layers, where the low angle etching is followed by a high angle etching to remove redeposition, improving the uniformity and reducing redeposition, thereby enhancing the characteristics of the magnetic memory.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If low angle ion beam etching is used to pattern magnetic layers, then etching efficiency is improved, but redeposition of magnetic material occurs which degrades device characteristics
Solution Approach 1:
The etching process is divided into multiple sequential steps with different beam angles. The first step uses a low beam angle (0° to 30°) for efficient patterning, followed by a second step using a high beam angle (60° to 85°) to remove redeposition. This segmentation allows each step to optimize for its specific function, resolving the contradiction between etching efficiency and device characteristics.
Solution Approach 2:
The invention converts the harmful effect of redeposition into a beneficial process by using the high angle ion beam etching in the second step to deliberately remove the redeposited material. The redeposition that initially degrades device characteristics becomes a temporary intermediate state that is subsequently eliminated, improving final device reliability.
2Device complexity
If conventional single-angle etching is used, then process simplicity is maintained, but redeposition cannot be effectively removed
Solution Approach 1:
The etching process is divided into multiple sequential steps with different beam angles. The first step uses a low beam angle (0° to 30°) for efficient patterning, followed by a second step using a high beam angle (60° to 85°) to remove redeposition. This segmentation allows each step to optimize for its specific function, resolving the contradiction between etching efficiency and device characteristics.
Solution Approach 2:
The invention converts the harmful effect of redeposition into a beneficial process by using the high angle ion beam etching in the second step to deliberately remove the redeposited material. The redeposition that initially degrades device characteristics becomes a temporary intermediate state that is subsequently eliminated, improving final device reliability.
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 reduces redeposition, improving the uniformity of the etching rate and preventing electrical short failures, thereby enhancing the performance and reliability of magnetic memory devices.
Implementation Method 1
a plasma generator in the etching chamber, the plasma generator being opposite to the stage and irradiating an ion beam toward the stage
Data Source
AI summary
According to one embodiment, an etching apparatus includes an etching chamber, a stage in the etching chamber, a plasma generator in the etching chamber, the plasma generator being opposite to the stage and irradiating an ion beam toward the stage, a supporter supporting the stage, the supporter having a rotational axis in a direction in which the ion beam is irradiated, a first driver changing a beam angle between a direction which is perpendicular to an upper surface of the stage and the direction in which the ion beam is irradiated, and a second driver which rotates the stage on the rotational axis.