Isocentric Ion Beam Scanning via Deflector Tilt
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Solution Overview
Problem
Existing ion implantation systems face challenges in achieving precise doping profiles due to beam-line variations, particularly with low-energy ion beams, which require complex and costly end stations for isocentric scanning, especially when angled ion implantation is necessary.
Innovation Solution
The technique involves tilting the ion beam to a predetermined angle using an electrostatic, magnetic, or electromagnetic field before directing it into the end station, allowing for two-dimensional wafer translation during isocentric scanning, eliminating the need for complex three-dimensional wafer movement and costly end station designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If isocentric scanning is implemented with angled ion implantation using conventional methods, then precise doping profiles can be achieved, but the end station design becomes complex and costly requiring three-dimensional wafer movement
Solution Approach 1:
Instead of tilting the wafer to achieve angled ion implantation (conventional approach), the patent inverts the approach by tilting the ion beam itself while keeping the wafer in a fixed orientation. This allows isocentric scanning to be performed with simple two-dimensional wafer translation, eliminating the need for complex three-dimensional wafer movement mechanisms while maintaining precise doping profiles.
Solution Approach 2:
The patent changes the dimension of wafer movement from three-dimensional (required in conventional angled implantation) to two-dimensional by tilting the ion beam. The wafer only needs to translate in the X and Y directions on a fixed plane, while the ion beam tilt angle provides the angular component, effectively reducing system complexity.
2Manufacturing precision
If low-energy ion beams are used for wafer implantation, then smaller feature sizes can be processed, but beam-line variations cause different dopant profiles across the wafer surface
Solution Approach 1:
The patent applies preliminary action by tilting the ion beam to a predetermined angle before the beam enters the end station. This pre-tilting ensures that as the wafer translates in two dimensions, the beam spot remains stationary relative to the wafer surface (isocentric scanning), preventing beam-line variations from causing doping profile inconsistencies across different wafer regions.
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 approach simplifies the end station design, reduces costs, and ensures consistent dopant profiles across the wafer surface by maintaining the ion beam at a fixed angle during scanning, thereby improving beam utilization and uniformity.
Implementation Method 1
The deflector may tilt the ion beam with an electrostatic field, a magnetic field, or an electromagnetic field.
Implementation Method 2
The deflector may tilt the ion beam with an electrostatic field, a magnetic field, or an electromagnetic field.
Implementation Method 3
The deflector may tilt the ion beam with an electrostatic field, a magnetic field, or an electromagnetic field.
Implementation Method 4
Ion implantation is a process of depositing chemical species into a substrate by direct bombardment of the substrate with energized ions.
Data Source
AI summary
A technique for isocentric ion beam scanning is disclosed. In one particular exemplary embodiment, the technique may be realized by an apparatus for isocentric ion beam scanning. The apparatus may comprise an end station having a mechanism for holding and translating a wafer. The apparatus may also comprise a deflector that tilts an ion beam to a predetermined angle and directs the ion beam into the end station. The wafer may be translated with respect to the ion beam for isocentric scanning at least a portion of a surface of the wafer, and wherein the ion beam is maintained at the predetermined angle during isocentric scanning.