Non-Uniform Helium Implantation for Controlled Wafer Splitting
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Solution Overview
Problem
Existing methods for splitting a workpiece using ion implantation result in random split initiation due to uniform doses of hydrogen or hydrogen and helium, leading to potential damage and inefficiency in thermal or mechanical processing.
Innovation Solution
Implementing a non-uniform dose of helium alongside a uniform dose of hydrogen by adjusting the scan speed or ion beam current, ensuring a higher dose at the workpiece periphery to control split initiation at the edge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a uniform dose of hydrogen or hydrogen and helium is implanted into the workpiece, then the entire surface receives consistent implantation, but random split initiation occurs with no control over where the split begins
Solution Approach 1:
The patent applies local quality by implanting helium at a non-uniform dose distribution, specifically increasing the dose at the periphery region compared to the center. This creates localized differences in microbubble formation and stress distribution, enabling controlled initiation of splits at specific peripheral locations rather than random initiation across the entire workpiece surface.
Solution Approach 2:
The patent introduces asymmetry in the implantation process by using a non-uniform helium dose that is higher at the periphery than at the center. This asymmetric dose distribution creates preferential stress concentration zones at the edges, guiding the split initiation to occur at predetermined peripheral locations rather than uniformly or randomly across the workpiece.
2Productivity
If a uniform dose of hydrogen and helium is used, then the implantation process is simple, but thermal or mechanical processing becomes less efficient and may cause damage due to uncontrolled split initiation
Solution Approach 1:
The patent applies preliminary action by pre-positioning higher concentrations of helium at the periphery through non-uniform implantation before the thermal or mechanical splitting process. This pre-established stress concentration pattern guides the split propagation along predetermined paths, enabling more efficient and controlled splitting while reducing uncontrolled damage to the workpiece.
3Reliability
If the implanted dose is optimized for split propagation, then effective splitting is achieved, but the dose distribution remains uniform causing random split initiation
Solution Approach 1:
The patent combines local quality with split propagation optimization by using a non-uniform helium dose distribution that is higher at the periphery. This localized dose enhancement at edge regions creates reliable stress concentration zones that both initiate splits predictably and ensure effective propagation across the workpiece, achieving both control and reliability simultaneously.
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 allows for precise control over split initiation and propagation, reducing damage and improving the efficiency of the splitting process by optimizing the thermal or mechanical stress on the workpiece.
Implementation Method 1
a non-uniform dose of helium is implanted into the workpiece by altering at least one of a scan speed of the workpiece and an ion beam current of the helium
Implementation Method 2
implanting a first species into an entire surface of the workpiece... implanting a uniform dose of hydrogen into the workpiece
Data Source
AI summary
A first species is implanted into an entire surface of a workpiece and helium is implanted into this entire surface with a non-uniform dose. The first species may be, for example, hydrogen, helium, or nitrogen. The helium has a higher dose at a portion of a periphery of the workpiece. When the workpiece is split, this split is initiated at the periphery with the higher dose. The non-uniform dose may be formed by altering a scan speed of the workpiece or an ion beam current of the helium. In one instance, the non-uniform dose of the helium is larger than a uniform dose of the hydrogen.