Crystal Wafering with 3D Defect Mapping and Axis-Aligned Slicing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for wafering industrially grown crystals, such as sapphire, silicon, or silicon carbide, are time-consuming, costly, and result in significant waste due to internal defects in the crystals.
Innovation Solution
A method and system for wafering crystals that involves scanning the crystal to create a 3D digital model, measuring crystal axes, optimizing core extraction and slicing to minimize defects, and adjusting the slicing tool position to reduce waste and increase yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional manual methods are used to determine crystal axes and optimize core distribution, then human operators can make decisions on layout, but the process becomes time-intensive and costly
Solution Approach 1:
The patent replaces manual human operator measurements and decisions with an automated optical measurement system that captures 3D images of the crystal, automatically determines crystal axes through image processing, and computes optimal core distributions using a computer. This substitution of mechanical/manual operations with automated optical and computational systems directly resolves the contradiction by eliminating time-intensive manual work while maintaining or improving decision quality.
Solution Approach 2:
The patent creates a digital 3D model (copy) of the crystal from optical images, which allows virtual planning and optimization of core extraction without physically handling or measuring the actual crystal repeatedly. This digital copy enables rapid iteration and optimization that would be time-consuming with physical measurements, thus reducing process time while preserving operational quality.
2Productivity
If conventional processes are used to extract cores and slice wafers, then production can proceed, but significant waste occurs due to internal defects in the crystals
Solution Approach 1:
The patent performs preliminary 3D scanning and defect mapping of the crystal before any core extraction or wafer slicing occurs. By identifying the spatial locations of internal defects in advance, the system can pre-plan core positions and slicing offsets to avoid defective regions, thereby maximizing yield and minimizing waste before the actual production process begins.
Solution Approach 2:
The patent computes an optimized offset position for the slicing tool along the crystal axis, shifting the slicing pattern by a calculated amount to minimize the number of wafers containing defects. This parameter adjustment (offset position) transforms the slicing process from a fixed-pattern operation to an optimized operation that adapts to the specific defect distribution in each crystal, thereby reducing waste while maintaining productivity.
3Loss of substance
If automated computing is used to determine offset position, then waste is minimized and yield increases, but the system complexity increases
Solution Approach 1:
The patent introduces a computer as an intermediary that processes the 3D crystal model and defect data to compute optimal offset positions. Rather than requiring complex mechanical adjustment mechanisms or manual calculation procedures, the computational intermediary handles the optimization complexity in software, keeping the physical slicing system relatively simple while achieving waste reduction through intelligent computation.
Data Source
AI summary
A method of producing wafers or discs from an industrially grown crystal includes:scanning a crystal in volume and forming a 3D volumetric digital model of the crystal,recording 3D spatial coordinates of defects detected during said scanning,measuring one or more crystal axes provided by a crystalline structure of the crystal, and recording this crystal axis in said 3D model of the crystal,coring out one or more cores from the crystal in a selected crystal direction which is parallel to one of said crystal axes or at a defined angle with respect to said crystal axis, andslicing the core orthogonally to the selected crystal direction with a wafer slicing machine comprising a slicing tool comprising a plurality of cutting wires or blades spaced at a regular slicing pitch configured to cut wafers of identical thicknesses from the core.