Ion Beam Extraction Assembly for High-Angle Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ion beam processing techniques for complex 3D semiconductor structures face non-uniformity issues due to inherent beam divergence when using ion beams with high incidence angles, leading to variations in ion beam dose across the wafer surface during scanning.
Innovation Solution
A plasma processing apparatus with a novel ion extraction optics system, including a plasma chamber, a plasma plate, a beam blocker, a non-planar electrode, and an extraction plate, which generates high-angle ion beams by applying a bias voltage to extract ion beamlets through aligned apertures, allowing for controlled angular distribution and uniform processing of substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If ion beams are extracted at zero degrees and the wafer is tilted to achieve high incidence angles, then high incidence angles (>50°) can be obtained for controlled etching of trench sidewalls, but process non-uniformity occurs across the wafer surface due to inherent beam divergence causing variation in ion beam dose
Solution Approach 1:
The single ion beam is segmented into multiple beamlets by the aperture plate with multiple apertures. This segmentation allows each beamlet to be independently directed at high angles to specific regions of the substrate, enabling high incidence angle processing while maintaining uniform dose distribution across the entire substrate surface through coordinated scanning of multiple beamlets.
Solution Approach 2:
The invention transitions from a single zero-degree extracted beam requiring wafer tilting to a multi-beamlet configuration where beamlets are extracted at high angles in multiple dimensions. The aperture plate creates a spatial distribution of beamlets that can simultaneously cover different areas of the substrate, adding a dimensional aspect to beam delivery that eliminates the need for wafer tilting while maintaining high incidence angles.
2Temperature
If a single ion beam is used with wafer tilting and scanning, then high incidence angles can be achieved, but the system complexity increases due to the need for precise wafer positioning and scanning mechanisms
Solution Approach 1:
Instead of tilting the wafer to achieve high incidence angles, the invention inverts the approach by extracting multiple beamlets at high angles from the plasma source and directing them onto a horizontally positioned substrate. This inversion eliminates the need for complex wafer tilting and scanning mechanisms, simplifying the overall system while maintaining high incidence angle processing capability.
Solution Approach 2:
The single complex beam path requiring wafer tilting and scanning is segmented into multiple simpler beamlet paths that can be generated simultaneously by the aperture plate. Each beamlet travels in a fixed high-angle trajectory, eliminating the need for dynamic wafer positioning and reducing mechanical complexity.
3Device complexity
If ion beams are extracted through a single aperture, then the extraction optics can be compact, but the beam angular distribution is limited and cannot achieve high mean angles required for sidewall etching
Solution Approach 1:
The single aperture is segmented into multiple apertures in the aperture plate, creating multiple extraction paths for ion beamlets. Each aperture can be optimized for specific angular distribution requirements, enabling the system to achieve high mean angles (>50°) necessary for sidewall etching while maintaining a compact extraction optics design without requiring complex tilting mechanisms.
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 system achieves uniform ion beam distribution across the substrate, enabling effective processing of complex 3D structures with high-angle ion beams, reducing contamination and maintaining a compact ion beam source design.
Implementation Method 1
applying a bias voltage to extract ion beamlets through a pair of apertures, defined by the plasma plate, the beam blocker, the non-planar electrode and the extraction plate
Implementation Method 2
generating a plasma in a plasma chamber
Data Source
AI summary
An ion beam processing apparatus may include a plasma chamber, and a plasma plate, disposed alongside the plasma chamber, where the plasma plate defines a first extraction aperture. The apparatus may include a beam blocker, disposed within the plasma chamber and facing the extraction aperture. The apparatus may further include a non-planar electrode, disposed adjacent the beam blocker and outside of the plasma chamber; and an extraction plate, disposed outside the plasma plate, and defining a second extraction aperture, aligned with the first extraction aperture.