Adaptive Ion Beam Scanning for Wafer Contour Matching
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Solution Overview
Problem
Current ion implantation methods result in beam waste and inefficiency due to a fixed scanning path that does not perfectly fit the circular shape of silicon wafers, leading to unnecessary ion beam implantation in cavity walls and reduced production capacity.
Innovation Solution
An ion implantation method that adjusts the scanning width of a spot-shaped ion beam current in real-time based on the width of the wafer being scanned, using a deflection unit and beam current sensor to control the scanning path, ensuring a circular distribution that matches the wafer shape, thereby reducing beam waste and increasing effective beam flow without increasing the actual beam current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed rectangular scanning path is used for ion beam implantation, then the control is simple and uniform doping is achieved, but the ion beam is wasted on cavity walls and non-wafer areas
Solution Approach 1:
The patent applies dynamics by making the scanning path adaptive rather than fixed. The ion beam scanning path dynamically adjusts to match the circular wafer geometry, changing from a static rectangular pattern to a dynamic circular contour-following path. This allows the system to maintain simple control while eliminating waste on cavity walls by conforming the scanning path to the actual wafer shape.
Solution Approach 2:
The patent changes the scanning path parameters from a fixed rectangular coordinate system to a variable path that follows the circular wafer contour. By modifying the scanning parameters to adapt to the wafer geometry, the system achieves both simple control and reduced ion beam waste, resolving the contradiction between operational simplicity and material efficiency.
2Device complexity
If the ion beam scanning path does not match the wafer shape, then the scanning system is simpler, but the production capacity is reduced due to beam waste
Solution Approach 1:
The scanning system uses dynamic path adjustment to match the circular wafer geometry without significantly increasing system complexity. By implementing an adaptive scanning path that follows the wafer contour, the system improves productivity by eliminating beam waste while maintaining relatively simple scanning control mechanisms.
Solution Approach 2:
The patent modifies the scanning path parameters to conform to the wafer shape, transforming the scanning approach from a fixed geometric pattern to an adaptive contour-following path. This parameter change increases effective beam utilization and production capacity without requiring complex additional hardware.
3Manufacturing precision
If a spot-shaped ion beam is used for precise doping control, then the doping precision is improved, but the beam must scan the entire wafer surface increasing complexity
Solution Approach 1:
The patent applies dynamics by making the scanning path adaptive to the wafer geometry while maintaining spot beam precision. The dynamic circular scanning path allows the focused spot beam to cover the entire wafer surface efficiently, achieving uniform doping without requiring overly complex scanning mechanisms. The system dynamically adjusts the path to match the circular wafer shape, simplifying the overall scanning complexity.
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 method effectively reduces beam waste and increases production capacity by ensuring the ion beam is uniformly implanted on the wafer surface, improving the efficiency of the ion implantation process and minimizing pollution in the implanter cavity.
Implementation Method 1
controlling the spot-shaped ion beam current to scan back and forth in a second direction perpendicular to the first direction
Implementation Method 2
Ion implantation introduces impurities into the silicon wafer by high-pressure ion bombardment, and the impurities can be implanted only by atomic high-energy collision with the silicon wafer
Data Source
AI summary
The present disclosure provides an ion implantation method and an ion implanter for realizing the ion implantation method. The above-mentioned ion implantation method comprises: providing a spot-shaped ion beam current implanted into the wafer; controlling the wafer to move back and forth in a first direction; controlling the spot-shaped ion beam current to scan back and forth in a second direction perpendicular to the first direction; and adjusting the scanning width of the spot-shaped ion beam current in the second direction according to the width of the portion of the wafer currently scanned by the spot-shaped ion beam current in the second direction. According to the ion implantation method provided by the present disclosure, the scanning path of the ion beam current is adjusted by changing the scanning width of the ion beam current, so that the beam scanning area is attached to the wafer, which greatly reduces the waste of the ion beam current, improves the effective ion beam current and increases productivity without increasing actual ion beam current.