Titanium Tungsten Layer Termination Angle Control
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Solution Overview
Problem
Integrated circuit components with titanium tungsten layers are prone to cracking and seam formation due to steep termination angles, which can lead to device failure.
Innovation Solution
A method is developed to reduce termination angles in titanium tungsten layers by applying a photoresist material and exposing it under defocused conditions, followed by etching, resulting in sloped terminations with angles of less than 32 degrees, thereby preventing cracks and seams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional photolithography exposure is used, then manufacturing process is simple, but termination angles are steep causing cracks and seams
Solution Approach 1:
The photoresist is exposed under defocused conditions before etching to pre-form the sloped termination profile. This preliminary action creates the desired angle geometry in the photoresist mask, which then transfers to the titanium tungsten layer during etching, preventing cracks and seams before they can occur.
Solution Approach 2:
The exposure is performed under defocused conditions, changing the optical parameter from focused to defocused. This parameter change in the photolithography process creates the sloped termination angle instead of a vertical edge, directly addressing the crack and seam problem while maintaining manufacturing simplicity.
2Manufacturing precision
If photoresist is exposed under defocused condition, then sloped termination is achieved, but exposure process complexity increases
Solution Approach 1:
Changing the exposure condition from focused to defocused is a single parameter adjustment in the photolithography process. This parameter change achieves consistent sloped terminations without requiring additional process steps, equipment, or complex procedures, thus maintaining process simplicity while improving precision.
3Reliability
If etching removes photoresist completely, then clean edges are formed, but steep angles cause cracking
Solution Approach 1:
The photoresist is pre-shaped with sloped edges through defocused exposure before etching occurs. This preliminary shaping ensures that when the etch removes the photoresist, the titanium tungsten layer follows the sloped profile, creating gentle termination angles that prevent cracking while still achieving complete photoresist removal for clean edges.
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 consistently maintains termination angles at 32 degrees or less, reducing the likelihood of cracks and seams in titanium tungsten layers, enhancing the reliability of bulk acoustic wave devices by preventing discontinuities and failures.
Implementation Method 1
The photo resist material is exposed under a defocus condition to generate a resist mask
Implementation Method 2
The titanium tungsten layer is etched with an etching material, wherein the etching material at least partially etches the photo resist material exposed under the defocused condition
Data Source
AI summary
Method of forming a termination angle in a titanium tungsten layer include providing a titanium tungsten layer and applying a photo resist material to the titanium tungsten layer. The photo resist material is exposed under a defocus condition to generate a resist mask, wherein an edge of the exposed photo resist material corresponds to the sloped termination. The titanium tungsten layer is etched with an etching material, wherein the etching material at least partially etches the photo resist material exposed under the defocused condition, and wherein the etching results in the sloped termination in the titanium tungsten layer.