Semiconductor Align Mark Light-Transmitting Protection Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor devices experience alignment errors due to thickness deviations in the passivation layer, which affect the contrast of the alignment mark, leading to improper alignment during assembly and increased costs.
Innovation Solution
A semiconductor device with a pad electrode layer, an align mark layer, and a passivation layer, where a light-transmitting protecting layer covers the passivation layer, maintaining consistent contrast and reducing alignment errors, and a method involving forming a bump on the pad electrode layer and using a second barrier metal layer to prevent mutual diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a passivation layer is formed on the align mark layer to protect the semiconductor device, then the device protection is improved, but the alignment error increases due to thickness deviation affecting the contrast of the align mark layer
Solution Approach 1:
A light-transmitting protecting layer is introduced as an intermediary between the passivation layer and the align mark layer. This intermediate layer transmits light to maintain the contrast of the align mark layer while providing protection, thus resolving the contradiction between device protection and alignment precision.
Solution Approach 2:
The light-transmitting protecting layer is selectively positioned to cover only specific regions where alignment marks are located, while the passivation layer provides general protection. This localized approach preserves the optical properties needed for alignment while maintaining overall device protection.
2Manufacturing precision
If the thickness of the passivation layer is controlled to maintain alignment contrast, then the alignment precision is improved, but the manufacturing complexity increases due to stringent thickness control requirements
Solution Approach 1:
The light-transmitting protecting layer serves as a mediator that decouples the relationship between passivation layer thickness and alignment contrast. By introducing this intermediate layer, the system becomes less sensitive to passivation layer thickness variations, reducing process control complexity while maintaining alignment precision.
Solution Approach 2:
The invention changes the optical parameters of the protecting layer by making it light-transmitting, which fundamentally alters how light interacts with the align mark layer. This parameter change makes the system robust against thickness variations without requiring stringent control.
3Manufacturing precision
If a light-transmitting protecting layer is added to cover the passivation layer, then the alignment error is reduced by maintaining consistent contrast, but the device complexity increases due to additional layer structure
Solution Approach 1:
The light-transmitting protecting layer performs multiple functions: it protects the underlying structures, maintains light transmission for alignment mark visibility, and provides a planar surface for subsequent processing. By consolidating these functions into a single layer, the actual increase in complexity is minimized despite the additional structural element.
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 solution enhances alignment sensitivity and reduces alignment errors by maintaining consistent contrast, even with variations in the light-transmitting protecting layer thickness, and simplifies the fabrication process while preventing damage to the align mark layer.
Implementation Method 1
a light-transmitting protecting layer covering at least a portion of the passivation layer, exposing the portion of the top of the pad electrode layer exposed from the passivation layer, and covering the portion of the top of the align mark layer exposed from the passivation layer
Data Source
AI summary
A semiconductor device includes a pad electrode layer and an align mark layer, formed on the semiconductor substrate. A passivation layer is formed on the semiconductor substrate and exposes at least a portion of the top of the pad electrode layer and at least a portion of the top of the align mark layer. A light-transmitting protecting layer covers at least a portion of the passivation layer, exposes the top portion of the pad electrode layer exposed from the passivation layer, and covers the portion of the align mark layer exposed from the passivation layer.