Probe Tip Fabrication Using Patterned Protective Layer
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Solution Overview
Problem
Conventional methods for fabricating probe tips result in a front end with a 54.7-degree angle due to crystallographic reasons, leading to rapid surface size increase during wear, making it difficult to maintain miniaturization and accuracy, especially when mechanical processes like sanding deteriorate fabrication precision.
Innovation Solution
A method involving the formation of a patterned first protective layer to expose the front end of the probe tip, followed by a trench formation and secondary coating processes to create a sharp front end without relying on mechanical processes like sanding, allowing for adjustable angles and precise control over the probe tip's shape and size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional fabrication method is used to form a probe tip on a silicon wafer, then the probe tip can be manufactured with standard processes, but the front end of the probe tip will have a fixed angle of 54.7 degrees due to crystallographic reasons, causing the surface size to increase rapidly during wear
Solution Approach 1:
A protective layer is formed on the silicon wafer before forming the probe tip. This preliminary action allows the front end angle to be controlled by the protective layer's thickness and pattern rather than being determined by silicon crystal orientation, enabling precise angle control (e.g., 45 degrees) while maintaining ease of manufacture through standard semiconductor processes
Solution Approach 2:
The invention changes the controlling parameter for the front end angle from silicon crystal orientation (which fixes the angle at 54.7 degrees) to the protective layer's dimensions (which can be precisely controlled during fabrication). This parameter change allows the angle to be adjusted to optimal values for minimizing wear-induced surface size increase
2Area of moving object
If mechanical processes like sanding are applied to reduce the front end surface size, then the surface size can be reduced, but the fabrication precision deteriorates notably
Solution Approach 1:
The protective layer is formed with the desired pattern and thickness before the probe tip is created. This preliminary structuring defines the exact front end geometry, eliminating the need for subsequent mechanical reduction processes like sanding that would compromise precision
Solution Approach 2:
The invention replaces mechanical reduction processes (sanding, machining) with a deposition-based approach where the protective layer is formed using standard semiconductor fabrication techniques. This substitution maintains fabrication precision while achieving the desired front end surface size
3Manufacturing precision
If the probe tip front end is made sharp to maintain miniaturization, then contact with miniaturized pads is improved, but the probe tip wears out faster due to the small surface area
Solution Approach 1:
The protective layer provides localized protection at the probe tip's front end, creating an optimized geometry that balances sharpness and durability. The front end can be designed with precise angles (e.g., 45 degrees) that maintain contact accuracy with miniaturized pads while the overall structure retains sufficient material to resist wear over the probe tip's service life
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 the fabrication of probe tips with a sharp front end that maintains precision and prevents rapid surface size increase during wear, eliminating the need for additional machining processes and ensuring accurate contact with miniaturized semiconductor pads.
Implementation Method 1
the photoresist layer 110 is exposed by means of an ultraviolet exposure device or the like by using a mask layer
Implementation Method 2
an exposed portion of the silicon nitride film 105 through the pattern of the photoresist layer 110 is etched by using a plasma device
Implementation Method 3
the silicon nitride film 105 formed on the silicon wafer 100 is removed by using phosphoric acid or the like
Implementation Method 4
the silicon wafer 100 having the silicon nitride film 105 formed thereon is dipped in a solution such as KOH, TMAH or the like capable of performing an anisotropic etching process on the silicon, whereby a trench 120 is formed
Data Source
AI summary
Disclosed is a method for fabricating a probe tip, capable of preventing a rapid increase of a surface size of a front end of the probe tip as the probe tip is worn out by a frequent contact with a wafer chip and, also, capable of improving the precision of the front end of the probe tip. The method for fabricating a probe tip includes forming a front end of the probe tip on a silicon wafer; forming a first protective layer which is patterned to expose a part of the front end of the probe tip; and forming a body of the probe tip in a portion opened by the pattern of the first protective layer.