Substrate Structure With Roughened Conductive Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge lies in forming a substrate structure with a thinner metal layer and smaller via aperture, as existing methods face difficulties in controlling via aperture during wet etching and often result in crater structures during dry etching due to small via apertures.
Innovation Solution
A substrate structure comprising a first conductive layer, a dielectric layer, and a second conductive layer, with a sacrificial layer used in a laser drilling process to form a via, where the aperture is controlled by adjusting the thickness of the sacrificial layer, allowing for precise formation of the via without generating protrusions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a wet etching process is used to form a via, then the etching process can be performed, but the via aperture cannot be controlled precisely when the metal layer thickness is less than 18 μm
Solution Approach 1:
A sacrificial layer is formed on the metal layer before the laser drilling process. This preliminary action protects the metal layer and enables precise via aperture control by using the sacrificial layer as a template during laser drilling, eliminating the need for wet etching that cannot control aperture precisely on thin metal layers.
Solution Approach 2:
The patent replaces the wet etching process with a laser drilling process. Laser drilling uses optical energy instead of chemical etchants to form vias, providing precise aperture control independent of metal layer thickness, thereby resolving the contradiction between thin metal layers and precise via aperture control.
2Ease of manufacture
If a dry etching process is performed on the metal layer, then the etching can be completed, but a crater structure is generated due to small via aperture
Solution Approach 1:
The sacrificial layer acts as an intermediary between the laser beam and the metal layer. It absorbs excess laser energy and prevents direct interaction that would cause crater formation, thereby completing the etching process while maintaining via structure uniformity without the harmful crater effects.
3Volume of moving object
If the metal layer is made thinner to decrease substrate structure size, then the device size decreases, but the via aperture control becomes difficult
Solution Approach 1:
The sacrificial layer is formed in advance on the thin metal layer before laser drilling. This preliminary protective layer enables precise via aperture control even when the metal layer is very thin, allowing substrate structure size reduction without sacrificing manufacturing precision.
Solution Approach 2:
The patent replaces traditional wet etching with laser drilling assisted by a sacrificial layer. This substitution enables precise via formation on thin metal layers, allowing further reduction of substrate structure size while maintaining or improving via aperture control.
4Device complexity
If laser drilling is performed without a sacrificial layer, then the process is simpler, but protrusions are generated on the metal layer surface
Solution Approach 1:
The sacrificial layer serves as a mediator between the laser beam and the metal layer during laser drilling. It prevents direct laser-metal interaction that causes protrusion formation, maintaining surface uniformity. Although it adds a process step, it is removed after via formation, so the final device complexity increase is minimal.
Solution Approach 2:
The sacrificial layer is a temporary, disposable component used only during the laser drilling process. It performs its protective function and is then removed, leaving no permanent trace in the final device. This approach accepts temporary process complexity to achieve permanent surface quality improvement.
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 enables the formation of substrate structures with precise via apertures and reduced surface roughness, suitable for high-frequency semiconductor devices, improving design and performance by preventing crater formation and maintaining uniform thickness.
Implementation Method 1
performing a laser drilling process to form a via exposing the first conductive layer
Data Source
AI summary
A substrate structure and a method for manufacturing the same are provided. The substrate structure includes a first conductive layer, a dielectric layer, a second conductive layer and a connection layer. The dielectric layer is disposed on the first conductive layer. The dielectric layer defines an opening exposing the first conductive layer. The second conductive layer is disposed on the dielectric layer. The connection layer extends from an upper surface of the first conductive layer to a lateral surface of the second conductive layer. A surface roughness of an upper surface of the second conductive layer ranges from about 0.5 μm to about 1.25 μm.