Segmented Electrode Assembly for Ion Beam Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ion implanters face challenges in achieving uniform beam current profiles during ion beam extraction due to variations in electrode characteristics, contaminants, pressure, and temperature, leading to non-uniform ion implantation on semiconductor wafers.
Innovation Solution
A segmented electrode assembly with actuators is used to displace electrode segments within the extraction slot, allowing for precise control of ion beam current density by modifying the position of the segments, thereby achieving a uniform beam profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single electrode with a slot is used to extract ions, then the structure is simple, but the beam current density is non-uniform
Solution Approach 1:
The electrode is divided into multiple independently controllable segments along the slot length. Each segment can be adjusted individually to compensate for non-uniform beam current density, transforming a single complex electrode into multiple simpler controllable units that collectively achieve uniform beam extraction
Solution Approach 2:
The electrode segments are made dynamically adjustable through actuators that can change the position of each segment in real-time. This dynamic capability allows the system to adapt to varying beam conditions and maintain uniform current density across the beam profile
2Manufacturing precision
If insulating sections are added to prevent interference between electrode sections, then the device complexity increases, but beam uniformity is only partially improved
Solution Approach 1:
The harmful interference effect is isolated and contained by extracting only the necessary insulating function into specific insulating sections, while the rest of the electrode maintains its conductive and adjustable properties. This selective extraction of the insulating function minimizes added complexity while achieving the desired beam uniformity
3Ease of operation
If actuators are used to displace insulating ring portions, then power delivery control is achieved, but beam non-uniformities are not sufficiently corrected
Solution Approach 1:
Instead of moving insulating components to control the beam, the invention inverts the approach by moving conductive electrode segments themselves to directly control beam extraction. The actuators now displace functional electrode portions rather than passive insulating elements, directly addressing the root cause of beam non-uniformity
4Manufacturing precision
If corrector magnet rods and poles are employed for beam uniformity tuning, then beam profile can be adjusted, but tune times are long
Solution Approach 1:
The magnetic field-based corrector system is replaced with a direct mechanical adjustment system where electrode segments are physically positioned to control beam extraction. This mechanical substitution at the source provides faster response times compared to adjusting magnetic fields downstream, reducing the overall tune time while maintaining beam uniformity
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 corrects beam current density non-uniformities, ensuring consistent ion implantation across the wafer surface, improving the uniformity and accuracy of semiconductor device fabrication.
Implementation Method 1
The series of electrodes are regulated at particular voltages with respect to ground to extract ions from the ion source chamber
Data Source
AI summary
An electrode assembly for use with an ion source chamber or as part of an ion implanter processing system to provide a uniform ion beam profile. The electrode assembly includes an electrode having an extraction slot with length L aligned with an aperture of the ion source chamber for extracting an ion beam. The electrode includes a plurality of segments partitioned within the length of the extraction slot where each of the segments is configured to be displaced in at least one direction with respect to the ion beam. A plurality of actuators are connected to the plurality of electrode segments for displacing one or more of the segments. By displacing at least one of the plurality of electrode segments, the current density of a portion of the ion beam corresponding to the position of the segment within the extraction slot is modified to provide a uniform current density beam profile associated with the extracted ion beam.