Semiconductor Wafer Backside Dicing with Sacrificial Layer
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Solution Overview
Problem
Existing semiconductor wafer dicing techniques, such as blade dicing, cause debris, chipping, and damage, while stealth dicing from the backside can result in tape residue on patterned surfaces, affecting the functionality of optical devices.
Innovation Solution
A sacrificial layer is formed on the backside of the semiconductor wafer to isolate the patterned surface from the tape, preventing contamination and residue during the dicing process, and a specialized tape is used for expansion to separate individual chips without adhering to the optical devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If stealth dicing from the backside is used, then damage to the semiconductor material is reduced, but tape residue is deposited on the patterned surface affecting optical device functionality
Solution Approach 1:
A sacrificial layer is introduced as an intermediary between the patterned backside surface and the tape. This layer prevents direct contact between the tape and the patterned surface during dicing and expansion, thereby eliminating tape residue contamination while maintaining the benefits of backside dicing
Solution Approach 2:
The backside surface is segmented into two functional zones: the patterned surface that should remain clean, and the sacrificial layer that accepts the tape adhesion. This segmentation allows the tape to adhere to the sacrificial layer rather than the patterned surface, preventing contamination
2Manufacturing precision
If blade dicing is used, then debris and chipping are reduced, but the patterned surface becomes contaminated with debris
Solution Approach 1:
Instead of dicing from the front side where debris would directly contaminate the patterned surface, the dicing is performed from the backside. Combined with the sacrificial layer, this inversion ensures that any debris generated during dicing does not contact the patterned surface
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 prevents tape residue on optical devices, reduces damage to the semiconductor material, and ensures clean separation of chips, maintaining the functionality of patterned features and minimizing material loss.
Implementation Method 1
adhesion strength between the sacrificial layer and the patterned surface is larger than that between the sacrificial layer and the tape
Implementation Method 2
expanding the tape to separate the chips from each other
Data Source
AI summary
A method of processing a semiconductor wafer is provided. The method includes providing a semiconductor wafer having a front side and a back side, the semiconductor wafer provided with a circuit layer at the front side and a patterned surface at the back side, forming a sacrificial layer on the back side, mounting a tape on the sacrificial layer, the sacrificial layer isolating the patterned surface from the tape, wherein adhesion strength between the sacrificial layer and the patterned surface is larger than that between the sacrificial layer and the tape, dicing the semiconductor wafer at the back side through the tape, defining individual chips on the semiconductor wafer, and expanding the tape to separate the chips from each other.