Semiconductor Substrate Etching for Laser Dicing Strength
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Solution Overview
Problem
Laser dicing of wafers results in weakened die-strength of semiconductor elements due to microcracks and defects at the interface between the recast layer and the base material, leading to increased fracture risk during handling and reduced reliability of semiconductor devices.
Innovation Solution
A method of controlled etching is applied to remove part of the semiconductor material, specifically targeting microcracks and defects near the interface between the recast layer and the base material, using optimized etch compositions and processes to improve mechanical strength without damaging the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If laser dicing is used to separate semiconductor elements from wafers, then productivity is improved, but die strength deteriorates due to microcracks and defects at the interface between recast layer and base material
Solution Approach 1:
The patent applies preliminary action by performing controlled etching of the recast layer and interface region immediately after laser dicing, before the microcracks can propagate during subsequent handling. The etching process is specifically targeted to remove the recast layer and expose the interface region containing microcracks, thereby preventing future fracture issues before they occur during die handling or assembly operations
Solution Approach 2:
The patent extracts the harmful recast layer and interface region containing microcracks from the semiconductor substrate through controlled etching. By selectively removing this problematic layer, the source of microcracks and defects is eliminated, thereby improving die strength without affecting the underlying base material or semiconductor elements
2Object-generated harmful factors
If high pressure cleaning is applied to remove debris after laser dicing, then cleaning effectiveness is improved, but die strength further deteriorates due to damage of sensible surface structures
Solution Approach 1:
The patent performs preliminary etching to remove the recast layer and expose the interface region before applying any cleaning operations. This preliminary action eliminates the need for aggressive high-pressure cleaning that would damage the substrate, as the harmful recast layer is already removed and debris can be cleaned more gently
Solution Approach 2:
The patent replaces the mechanical high-pressure cleaning system with a chemical etching process that selectively removes the recast layer through chemical reaction rather than mechanical force. This substitution allows for effective removal of harmful materials without the mechanical stress and damage associated with high-pressure cleaning methods
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 enhances the die strength of semiconductor elements by removing crack-initiating defects, reducing the risk of fracture, and improving the reliability and service life of semiconductor devices.
Implementation Method 1
laser dicing method... laser ablation scribing process for forming scribing lines
Implementation Method 2
recast material deposited on said body during said laser processing
Implementation Method 3
a step of etching said substrate for removing from said body of semiconductor material recast material deposited on said body
Data Source
AI summary
A method and arrangement for treating a substrate processed using a laser beam, wherein said substrate comprises at least a body of semiconductor material. The method comprises a step of etching said substrate for removing from said body of semiconductor material recast material deposited on said body during said laser processing. The step of etching is controlled for removing in addition to said recast layer, at least a part of said semiconductor material of said body for improving mechanical strength of said substrate.