Wafer Metallization Openings for Laser Stealth Dicing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Laser stealth dicing struggles to effectively separate thick metal layers in semiconductor wafers, often causing damage and inefficiency, especially for larger chips with thick metallization structures.
Innovation Solution
Incorporating an easy-to-crack position within the metallization structures by forming openings such as slits or holes that intersect the separation line regions, allowing for precise laser machining without additional process steps and maintaining probing conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If laser stealth dicing is used to separate thick metal layers, then processing speed is improved, but separation quality deteriorates causing damage to the metal layers
Solution Approach 1:
The patent applies preliminary action by forming openings in the thick metal layers before the dicing process. These openings create weakened paths that guide the fracture during laser stealth dicing, ensuring clean separation without damaging the surrounding metal structures. The openings are created in advance to prepare the metal layers for successful separation.
Solution Approach 2:
The patent applies segmentation by dividing the thick metal layers into sections separated by openings. These openings act as predetermined fracture lines that guide the separation process, allowing the laser to cleanly split the metal layers along the opening paths without causing uncontrolled damage to the entire structure.
2Manufacturing precision
If mechanical dicing is used to separate thick metal layers, then separation quality is maintained, but processing speed decreases
Solution Approach 1:
The patent replaces the mechanical dicing system with a laser-based stealth dicing process. By combining laser processing with pre-formed openings in the metal layers, the method achieves clean separation similar to mechanical dicing but at much higher speeds, eliminating the need for physical contact and mechanical force.
3Reliability
If testlines and pads are placed in separation line regions for large chips, then electrical functionality is improved, but dicing difficulty increases due to thick metal layers
Solution Approach 1:
The patent applies preliminary action by creating openings in the thick metal layers of testlines and pads before dicing. This preparation ensures that when laser stealth dicing is performed, the fracture will follow the opening paths rather than rupturing the metal structures, thereby maintaining electrical functionality while enabling successful separation.
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
Enables efficient separation of thick metal layers during laser stealth dicing, reducing damage and improving processing efficiency for both small and large chips by creating a weakened path for fracture, thus facilitating clean separation without rupturing the thick metal layers.
Implementation Method 1
scanning a laser beam (typically, an infrared (IR) laser beam) along the separation line region or regions and secondly an underlying elastic carrier, e.g. a carrier membrane or tape, may be expanded to induce fracture of the wafer
Data Source
AI summary
A wafer in accordance with various embodiments may include: at least one metallization structure including at least one opening; and at least one separation line region along which the wafer is to be diced, wherein the at least one separation line region intersects the at least one opening.