Segmented Electrostatic Lens for Ribbon Ion Beam Shaping
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Solution Overview
Problem
Existing electrostatic triode deceleration lenses suffer from significant space charge effects that cause ion beam divergence and energy loss, limiting the effective dose and uniformity of ion beams in semiconductor manufacturing, particularly for low-energy ribbon-shaped beams.
Innovation Solution
An electrostatic lens with segmented suppression electrodes and independently biased focusing elements along the edges, allowing for flexible manipulation of ion beam shape and energy, including curved surfaces and adjustable distances, to counteract space charge effects and achieve precise equipotential boundaries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional electrostatic triode deceleration lenses are used, then ion beam energy can be controlled, but space charge effects cause significant ion beam divergence and energy loss
Solution Approach 1:
The suppression electrode is divided into multiple independently biased segments rather than a single electrode. This segmentation allows different regions of the electrode to apply different voltage potentials, creating localized electric field configurations that counteract space charge effects more effectively, thereby reducing ion beam divergence and energy loss
Solution Approach 2:
Different segments of the suppression electrode are biased at different potentials to create non-uniform electric fields tailored to local requirements. This local quality adjustment enables precise control over the electric field distribution, addressing space charge effects in specific regions where they are most problematic
2Use of energy by moving object
If conventional electrostatic triode deceleration lenses are used, then ion beam energy can be manipulated, but ion beam shape uniformity deteriorates due to space charge effects
Solution Approach 1:
The suppression electrode is segmented into multiple independently controllable sections, allowing differential biasing to maintain uniform ion beam shape across the beam profile. Each segment can be adjusted to compensate for local distortions caused by space charge effects
Solution Approach 2:
The voltage potentials applied to different suppression electrode segments are varied to optimize ion beam shape uniformity. By changing the electrical parameters (voltages) of individual segments, the electric field distribution is tuned to counteract space charge-induced distortions and maintain consistent beam shape
3Device complexity
If single voltage potential is applied to each electrode set, then device complexity is reduced, but ability to counteract space charge effects is limited
Solution Approach 1:
The suppression electrode is divided into multiple segments that can be independently biased, providing additional control degrees of freedom to counteract space charge effects. This segmentation increases control capability while maintaining manageable device complexity through modular architecture
Solution Approach 2:
The electrode system transitions from static, uniform biasing to dynamic, non-uniform biasing where different segments can be adjusted independently. This dynamic control allows the system to adapt to varying space charge conditions and optimize performance for different operating parameters
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 solution effectively reduces ion beam divergence and enhances dose uniformity, achieving less than 1% variations in dose and 0.5-degree angular uniformity, improving the transport and implantation of low-energy ribbon-shaped ion beams by mitigating space charge effects and electric field aberrations.
Implementation Method 1
By applying different combinations of voltage potentials to the multiple electrodes, the D1 and D2 deceleration lenses can manipulate ion energies
Implementation Method 2
The D1 and D2 deceleration stages (also known as 'deceleration lenses') are each comprised of multiple electrodes with a defined aperture
Implementation Method 3
The significant changes in ion energies that take place in the electrostatic triode deceleration lens can have a substantial impact on a shape of the ion beam. Space charge effects are more significant in low-energy ion beams
Data Source
AI summary
A technique for shaping a ribbon-shaped ion beam is disclosed. In one particular exemplary embodiment, the technique may be realized as an apparatus for shaping a ribbon-shaped ion beam. The apparatus may comprise an electrostatic lens having a substantially rectangular aperture for a ribbon-shaped ion beam to pass through, wherein a plurality of focusing elements are positioned along short edges of the aperture, and wherein each focusing element is separately biased and oriented to shape the ribbon-shaped ion beam.