Plasma Processing Apparatus Ion Shielding Plate
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Solution Overview
Problem
The existing plasma processing apparatuses fail to effectively separate ion and radical plasma generation, leading to unwanted ion irradiation during radical-only processing due to the lack of consideration for the vertical position of shielding plates, resulting in incomplete control over ion flux to the sample.
Innovation Solution
A plasma processing apparatus with a dielectric window and an ion shielding plate having through holes positioned at a distance greater than a predetermined radius from the center, combined with a magnetic field mechanism to control plasma generation, preventing ion penetration and ensuring isotropic etching with reduced ion flux and allowing anisotropic etching by adjusting the plasma generation regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a shielding plate is provided to shield ion incidence, then ion flux to sample is reduced, but electromagnetic waves may pass through and generate plasma below the shielding plate
Solution Approach 1:
The shielding plate is segmented with through-holes positioned at specific distances from the center. This segmentation allows selective passage of particles while maintaining the overall shielding function, preventing electromagnetic waves from generating unwanted plasma below the plate while still reducing ion flux to the sample.
Solution Approach 2:
The solution moves from considering only the vertical position of the shielding plate to incorporating the radial dimension by positioning through-holes at specific distances from the center. This two-dimensional positioning (radial distance and vertical position) enables precise control over particle and wave transmission.
2Ease of operation
If plasma is generated above the shielding plate for radical-only processing, then ion irradiation is reduced, but plasma may also generate below the shielding plate causing unwanted ion irradiation
Solution Approach 1:
The shielding plate with strategically positioned through-holes segments the plasma generation regions. During radical-only processing, plasma generated above the plate can pass through the through-holes while ions are blocked, enabling selective radical irradiation without unwanted ion irradiation from below the plate.
Solution Approach 2:
The through-holes in the shielding plate act as intermediaries that selectively transmit radicals while blocking ions. This intermediary structure enables the differentiation between radical-only processing and ion irradiation modes within the same chamber.
3Device complexity
If the same chamber is used for both isotropic and anisotropic etching, then device complexity is reduced, but control over ion flux and plasma generation becomes difficult
Solution Approach 1:
The system dynamically switches between different plasma generation modes by controlling the electromagnetic wave supply and magnetic field strength. The same chamber can adapt between isotropic etching (with shielding plate in place) and anisotropic etching (with adjusted plasma generation conditions) without structural modifications.
Solution Approach 2:
The shielding plate with through-holes serves multiple functions: it shields ions during radical-only processing, enables isotropic etching by blocking ion flux, and allows anisotropic etching when plasma is generated in specific regions. This universal component enables diverse etching modes in a single chamber.
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 enables both isotropic etching with reduced ion flux and anisotropic etching in the same chamber by preventing ion penetration and controlling plasma generation, effectively isolating ions from the sample during radical-only processing.
Implementation Method 1
a radio frequency power source configured to supply radio frequency power for generating plasma through a first member of a dielectric material disposed above the processing chamber
Implementation Method 2
a magnetic field forming mechanism configured to form a magnetic field inside the processing chamber
Implementation Method 3
a second member disposed between the first member and the sample stage and having a through hole formed therein, in which the through hole is formed at a position where a distance thereof from a center of the second member is a predetermined distance or more
Data Source
AI summary
An object of the invention is to provide a plasma processing apparatus capable of both isotropic etching in which a flux of ions to a sample is reduced and anisotropic etching in which ions are incident on a sample in the same chamber. For this purpose, the invention includes: a processing chamber in which a sample is subjected to plasma processing; a radio frequency power source configured to supply radio frequency power for generating plasma through a first member of a dielectric material disposed above the processing chamber; a magnetic field forming mechanism configured to form a magnetic field inside the processing chamber; a sample stage where the sample is placed; and a second member disposed between the first member and the sample stage and having a through hole formed therein, in which the through hole is formed at a position where a distance thereof from a center of the second member is a predetermined distance or more, and a distance from the first member to the second member is a distance such that a density of plasma generated between the first member and the second member is a cutoff density or higher.