Semiconductor Wafer Dicing Structure for Straight Cleavage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The laser dicing technique for semiconductor wafers results in low straightness of cleavage, leading to meandering of the division line during the thinning process, which can cause cracks to reach the device region inside the semiconductor chip.
Innovation Solution
A semiconductor wafer design that includes a first stacked body with alternately stacked first and second material films in the dicing region, which helps maintain linearity of the cleavage and prevents meandering of the division line.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If laser dicing technique is used to cleave the semiconductor wafer, then the wafer can be divided into chips, but the division line meanders and cracks may reach the device region
Solution Approach 1:
A groove structure is formed in advance at the dicing line position before the actual dicing process. This groove serves as a predetermined cleavage path that guides the laser dicing process, ensuring that the division line follows the straight groove rather than meandering. The groove is created using standard photolithography and etching processes, establishing a physical template for accurate chip separation.
Solution Approach 2:
The groove structure acts as an intermediary element between the laser dicing process and the final chip separation. During dicing, the laser modifies the material along the groove, and the cleavage propagates through the groove, using it as a pathway. This intermediary structure ensures that the division line remains straight and prevents cracks from deviating into the device region, while still enabling efficient wafer division.
2Length of moving object
If the semiconductor wafer is thinned in a polish process after laser modification, then the wafer thickness is reduced, but the division line curves largely
Solution Approach 1:
The groove structure is prepared in advance before the thinning process. During subsequent polishing and thinning operations, the groove structure remains as a physical guide that maintains the straightness of the division line. The groove walls provide mechanical constraints that prevent the division line from curving during the thinning process, ensuring that even as the wafer becomes thinner, the cleavage path remains linear and accurate.
3Ease of manufacture
If laser modification is applied to the semiconductor wafer, then the wafer can be cleaved, but the cleavage has low straightness
Solution Approach 1:
The groove structure serves as an intermediary that mediates between the laser modification process and the final cleavage outcome. The laser modifies the material within the groove, and the groove geometry ensures that the resulting cleavage follows a straight path. This intermediary structure transforms the inherently imprecise laser modification into a high-precision cleavage process by providing a physical template for the division line.
Solution Approach 2:
The groove structure changes the physical parameters of the dicing region, creating a localized structure with different mechanical and optical properties than the bulk wafer material. This parameter change in the dicing region enables the laser to produce straight cleavage by confining the modification and subsequent crack propagation within the groove boundaries, rather than allowing random meandering in the bulk material.
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 proposed design effectively restricts the meandering of the division line and prevents cracks from reaching the chip region, ensuring the integrity of the semiconductor chip.
Implementation Method 1
A laser dicing technique is a method using a laser to modify the inside of a semiconductor wafer to cleave the semiconductor wafer from a modified portion as the starting point
Data Source
AI summary
A semiconductor wafer according to the present embodiment includes a plurality of semiconductor chip regions and a division region. The plurality of semiconductor chip regions have a semiconductor element. The division region is provided between the semiconductor chip regions adjacent to each other. A first stacked body is provided on the division region. The first stacked body is configured with a plurality of first material films and a plurality of second material films alternately stacked.