Semiconductor Wafer Splitting via Stress-Guided Separation Regions
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Solution Overview
Problem
The integration of SiC wafer splitting into the standard SiC production process is complex and requires modifications, leading to inefficiencies and increased costs, necessitating a cost-sensitive and efficient method for integrating wafer splitting and production processes.
Innovation Solution
A method involving the formation of a separation region with altered physical properties to increase thermo-mechanical stress, followed by applying an external force or laser radiation to propagate cracks, allowing the wafer to split into two pieces, one retaining device structures, using carriers for stabilization and potentially combining techniques like ultrasonic vibrations or polymer application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If wafer splitting is integrated into standard SiC production process, then material utilization improves and costs reduce, but process complexity increases and requires modifications to production process
Solution Approach 1:
A separation region is formed within the semiconductor wafer before the splitting operation. This preliminary action creates a predefined path for crack propagation, enabling controlled splitting into a first wafer portion containing device structures and a second wafer portion for reuse. The separation region is created through laser radiation or ion implantation, which alters physical properties to facilitate subsequent clean separation without damaging the device structures.
Solution Approach 2:
The semiconductor wafer is divided into two distinct portions through controlled cracking along the separation region. The first wafer portion retains the device structures and is processed separately, while the second wafer portion is reclaimed and reused for forming additional device structures. This segmentation enables multiple utilization cycles of the original wafer material, reducing waste and overall production costs.
2Productivity
If external force is applied to propagate cracks along separation region, then wafer splitting efficiency improves, but risk of damaging device structures increases
Solution Approach 1:
The separation region is pre-formed within the wafer through laser radiation or ion implantation, creating a zone with altered physical properties that guides crack propagation. This preliminary preparation ensures that when external force is applied, cracks follow the predetermined separation region path rather than randomly propagating through the wafer, thereby protecting device structures from damage while maintaining splitting efficiency.
Solution Approach 2:
The separation region acts as an intermediary zone between the two wafer portions. It is formed by laser radiation or ion implantation that creates a controlled weakness path. When external force is applied, this intermediary region facilitates crack propagation in a controlled manner, enabling efficient splitting while preventing uncontrolled cracking that could damage device structures.
3Manufacturing precision
If laser radiation is used to increase thermo-mechanical stress in separation region, then controlled splitting is achieved, but energy consumption increases
Solution Approach 1:
Laser radiation is applied selectively only to the separation region rather than the entire wafer. This partial action concentrates energy where needed to create the separation zone with altered physical properties, achieving precise control over crack propagation paths while minimizing overall energy consumption. The laser parameters (power, duration, focal point) are optimized to provide sufficient stress concentration only in the separation region.
Solution Approach 2:
The laser radiation creates localized thermo-mechanical stress specifically in the separation region, altering physical properties only in that targeted area. This local modification enables precise control of crack propagation without requiring excessive energy input across the entire wafer. The separation region exhibits different physical properties (increased stress concentration) compared to the rest of the wafer, enabling controlled splitting with minimal energy expenditure.
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 reduces material waste, facilitates controlled and reproducible wafer splitting, and lowers manufacturing costs by reusing reclaimed wafers for additional device structures, while maintaining the integrity of the device structures.
Implementation Method 1
applying laser radiation to a separation region within the semiconductor wafer such that the separation region has increased thereto-mechanical stress relative to the remainder of the semiconductor wafer
Implementation Method 2
forming a separation region within the semiconductor wafer, the separation region having at least one altered physical property which increases thereto-mechanical stress within the separation region relative to the remainder of the semiconductor wafer
Implementation Method 3
applying an external force to the semiconductor wafer such that at least one crack propagates along the separation region and the semiconductor wafer splits into two separate pieces
Implementation Method 4
at least one crack propagates along the separation region and the semiconductor wafer splits into two separate pieces
Implementation Method 5
combining techniques like ultrasonic vibrations or polymer application
Data Source
AI summary
A method of splitting off a semiconductor wafer from a semiconductor bottle includes: forming a separation region within the semiconductor boule, the separation region having at least one altered physical property which increases thermo-mechanical stress within the separation region relative to the remainder of the semiconductor boule; and applying an external force to the semiconductor boule such that at least one crack propagates along the separation region and a wafer splits from the semiconductor boule.