Wire Saw Wafer Slicing With Independent Wire Group Compensation
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Solution Overview
Problem
Existing procedures for producing semiconductor slices using a wire saw face challenges in accurately compensating for axial movement due to heat expansion, leading to suboptimal warp and nanotopography in the produced slices.
Innovation Solution
The procedure involves dividing wires into multiple wire groups, each with its own compensation movement, activated by drive elements, to correct for misalignments in the cutting gap, thereby improving the precision of semiconductor slice production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If axial movement of wire guide rollers is used to compensate for thermal expansion, then thermal expansion can be approximately compensated, but the compensation is only approximate and cannot achieve high precision warp control
Solution Approach 1:
The wire arrangement is divided into multiple wire groups (e.g., four wire groups), each with its own drive element for independent actuation. This segmentation allows different regions of the wire field to be compensated independently, enabling precise control of cutting gap positions across the workpiece width, thereby achieving high precision warp control that exceeds simple axial movement compensation.
Solution Approach 2:
The system transitions from static wire guide roller positions to dynamic, independently controllable wire groups. Each wire group can be actuated separately by its drive element during the cutting process, allowing real-time adaptation to thermal expansion and other deviations, thus achieving superior precision compared to fixed axial compensation.
2Measurement precision
If temperature control of wire guide rollers is used to control axial positions of wires, then wire positions can be adjusted, but the control process is comparatively slow
Solution Approach 1:
The patent replaces thermal control mechanisms with direct mechanical actuation through drive elements (such as piezoelectric actuators) for each wire group. This mechanical substitution enables immediate, precise positioning of wires without the thermal inertia and slow response characteristics of temperature-based control, thereby achieving fast and accurate wire position control.
3Manufacturing precision
If axial movement of the entire workpiece is used to compensate for warp deviations, then some compensation can be achieved, but only partial compensation is possible and precision is limited
Solution Approach 1:
Instead of moving the entire workpiece axially, the patent segments the wire arrangement into multiple independently controllable wire groups. Each wire group can be actuated separately to compensate for local warp deviations, providing fine-grained control that achieves high precision compensation without requiring complex workpiece movement mechanisms.
Solution Approach 2:
The patent transitions from one-dimensional axial workpiece movement to multi-dimensional wire group actuation. By controlling multiple wire groups independently in the transverse direction (perpendicular to wire running direction), the system achieves precise warp compensation through a different dimensional approach, avoiding the limitations of simple axial displacement.
4Manufacturing precision
If wire groups are divided and independently actuated, then cutting gap position precision is improved, but the device complexity increases
Solution Approach 1:
The wire arrangement is divided into a manageable number of wire groups (e.g., four groups), each with its own drive element. This segmentation strikes a balance between achieving sufficient cutting gap position precision and avoiding excessive device complexity. The segmented approach allows independent control of critical regions while maintaining system simplicity through a limited number of actuation points.
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 results in semiconductor slices with reduced warp and improved nanotopography, enhancing the quality of the slices and reducing the need for subsequent refining processes.
Implementation Method 1
Electromagnetic, mechanical, hydraulic, pneumatic, magnetostrictive, and preferably piezoelectric actuators can be considered as drive elements
Data Source
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AI summary
A method for producing semiconductor wafers from a workpiece by machining the workpiece with a wire saw, a wire saw, and a semiconductor wafer made of single-crystal silicon. The method comprises feeding the workpiece by means of an arrangement of wires, which are grouped into wire clusters and tensioned between wire guide rollers and move in one direction; creating cutting gaps as the wires engage the workpiece; determining a misalignment of the cutting gaps in each wire cluster; and inducing compensatory movements of the wires in each wire cluster, depending on the determined misalignment of the cutting gaps in a direction perpendicular to the direction of travel of the wires, during the feeding of the workpiece by the arrangement of wires, by activating at least one drive element.