Semiconductor Test Pad Laser Annealing for Flat Bonding Surfaces
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Solution Overview
Problem
Current methods for ensuring flatness of surfaces in 3D IC bonding processes are complex and prone to metal contamination due to probe marks left by testing, which require additional layers and complex processes for removal and re-thickening of test pads.
Innovation Solution
The method involves using laser annealing to melt and reduce the height of protrusions on test pads, ensuring the surface is flat and preventing metal contamination by fusing the protrusions with the test pads, thus simplifying the process and maintaining the test pads' functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If etching process is employed to remove the first test pad exposed from the third insulating material layer, then the probe mark is eliminated, but the wiring complexity increases due to requiring two parallel test pads
Solution Approach 1:
The invention extracts and removes only the protruding metal portion of the test pad that causes the probe mark, while preserving the rest of the test pad structure and its electrical connection functionality. This selective removal eliminates the harmful protrusion without requiring complete test pad removal or additional parallel test pads, thus avoiding increased wiring complexity
Solution Approach 2:
The invention applies local quality by treating only the specific protruding region of the test pad with the etching process, while leaving the rest of the test pad intact. This localized treatment removes the harmful probe mark area while maintaining the electrical functionality of the test pad, avoiding the need for complex global redesign or additional test pads
2Object-generated harmful factors
If the test pad consists of at least two layers and the second metal layer is removed, then the probe mark is eliminated, but the process complexity and cost increase due to requiring growth of a third metal layer
Solution Approach 1:
The invention extracts and removes only the protruding second metal layer portion that creates the probe mark, while preserving the first metal layer and the electrical connection. This selective extraction eliminates the need for complete test pad removal and subsequent regrowth of entire metal layers, significantly reducing process complexity and cost
Solution Approach 2:
The invention discards only the harmful protruding portion of the second metal layer while recovering and preserving the functional first metal layer and its electrical connection. This selective discarding and recovery approach eliminates the probe mark without requiring complete test pad reconstruction, reducing manufacturing complexity
3Manufacturing precision
If additional insulating material layers are formed to cover the protrusion, then the surface flatness is improved, but the process complexity increases
Solution Approach 1:
The invention takes out and removes the protruding metal portion before forming subsequent insulating material layers. By eliminating the protrusion source first, the patent achieves surface flatness without requiring additional compensatory insulating layers, thus reducing process complexity while maintaining manufacturing precision
Solution Approach 2:
The invention performs preliminary action by removing the protruding test pad portion before forming the second insulating material layer. This preliminary removal ensures that subsequent layers can be formed with proper flatness without requiring additional corrective steps or extra insulating layers, reducing overall process complexity
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 achieves good surface flatness with reduced process complexity and lower costs by eliminating the need for additional layers and complex removal processes, while preventing metal contamination during bonding.
Implementation Method 1
heating and melting the protrusion by laser annealing
Implementation Method 2
heating and melting the protrusion by laser annealing, thereby reducing a height of the protrusion
Data Source
AI summary
A method of handling a test pad and a method of fabricating a semiconductor device are disclosed. The method of handling a test pad includes: providing a substrate formed thereon with a first insulating dielectric layer and a first test pad in the first insulating dielectric layer, wherein a surface of the first test pad is at least partially exposed from the first insulating dielectric layer, and there is a probe mark with a protrusion resulting from testing with probe tips on the surface portion of the first test pad exposed from the first insulating dielectric layer; and heating and melting the protrusion by laser annealing, thereby reducing a height of the protrusion. This invention can ensure good flatness of a surface to be bonded while enabling reduced process complexity and preventing metal contamination of the surface to be bonded.