Window Frame Magnet Assembly for Ion Beam Mass Resolution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ion implantation systems face challenges in achieving broad ribbon-shaped ion beams with uniform density and adequate mass resolution, often requiring complex and expensive architectures with inefficient magnetic field configurations and limited mass resolving power.
Innovation Solution
A single window frame magnet assembly with a special cross-field configuration, utilizing two pairs of magnetic coils to create both vertical and horizontal magnetic fields, deflects and focuses the ion beam to achieve uniform density and improved mass resolution, allowing for a single scan implantation of semiconductor wafers without additional mechanical or magnetic scanning devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional mass analysis apparatus with single magnet is used, then device complexity is reduced, but mass resolution and beam uniformity deteriorate
Solution Approach 1:
The magnet assembly is segmented into two independent pairs of coils (first pair for vertical field, second pair for horizontal field) that can be controlled separately. This segmentation allows each coil pair to optimize for its specific function while working together to achieve both mass resolution and beam uniformity, resolving the contradiction between device simplicity and performance.
Solution Approach 2:
The invention transitions from conventional single-plane magnetic field configuration to a two-dimensional cross-field configuration with vertical and horizontal components. This dimensional expansion enables simultaneous mass analysis (via horizontal deflection) and beam uniformity control (via vertical focusing), achieving both goals without proportionally increasing device complexity.
2Device complexity
If conventional single magnetic field configuration is used, then device complexity is reduced, but beam uniformity and mass resolution deteriorate
Solution Approach 1:
The magnetic field is segmented into two orthogonal components generated by separate coil pairs. The first pair (vertical field) controls beam uniformity through vertical focusing, while the second pair (horizontal field) handles mass analysis. This functional segmentation allows each field component to optimize for its specific role, achieving beam uniformity without excessive complexity.
Solution Approach 2:
Different regions of the magnet assembly provide different field characteristics: the vertical field region optimizes for beam uniformity and focusing, while the horizontal field region optimizes for mass resolution. This local optimization of field quality in different spatial regions enables simultaneous achievement of beam uniformity and mass resolution.
3Productivity
If broad ribbon beam is generated, then productivity is improved through single scan implantation, but mass resolution deteriorates due to reduced analyzing power
Solution Approach 1:
The invention uses a two-dimensional cross-field configuration where horizontal magnetic field components provide mass analysis (momentum resolution) while vertical components maintain beam uniformity. This dimensional separation allows broad ribbon beams to achieve both high productivity through single-scan implantation and adequate mass resolution, as the orthogonal field components independently optimize for their respective functions.
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 enables the generation of broad ribbon-shaped ion beams with enhanced mass resolution and uniform density, reducing system complexity and cost while allowing for efficient single-scan implantation of semiconductor wafers, and supports the use of smaller ion sources, improving beam transmission and mass analysis capabilities.
Implementation Method 1
a mass analysis magnet for mass resolving the ion beam
Implementation Method 2
a single window frame magnet assembly operable to receive a broad ribbon-shaped ion beam and deflect the ion beam
Data Source
AI summary
An ion implantation system for providing a mass analyzed ribbon beam that comprises an ion beam source that includes a plasma source and an extraction component, wherein the extraction component is configured to extract a diverging ion beam and direct the ion beam to a window frame magnet assembly. The window frame magnet assembly comprises two pairs of coils orthogonally arranged within a window shaped yoke to produce an independently controllable uniform cross-field magnetic field. The first set of coils create an uniform field across the width of the diverging beam to convert it to a uniform parallel broad ion beam. The second set of coils bend the sheet of the ion beam in orthogonal direction to give mass dispersion for ion mass selection.