Semiconductor Contact Pad Slot for Halide Contamination Control
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Solution Overview
Problem
The existing bond pad structures in semiconductor devices are prone to contamination and corrosion due to the diffusion of halides from molding compounds during the molding process, which affects the electrical connection between the copper pads and vias, leading to delamination and reliability issues.
Innovation Solution
A semiconductor structure with a conductive pad, a slot filled with insulating material through the pad, and a passivation layer exposing a portion of the pad, along with electrical interconnects, is designed to divert contaminants away from the vias, using dummy interconnects and metals to absorb contaminants and reduce exposure to the main interconnects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a copper pad with TaN/Ta liner and vias is used for electrical connection, then electrical conductivity is improved, but contamination and corrosion occur due to halide diffusion from molding compound
Solution Approach 1:
A slot filled with insulating material is introduced as an intermediary barrier between the copper pad and the molding compound. This slot prevents direct contact and diffusion pathways, blocking halide contaminants from reaching the copper pad and vias while maintaining the electrical connection function through the pad structure.
Solution Approach 2:
The copper pad structure is segmented by introducing a slot that divides the pad into regions. This segmentation creates a physical barrier that interrupts the diffusion path of halide contaminants, allowing the pad to maintain its electrical function while protecting the underlying vias from contamination.
2Strength
If molding compound is deposited over semiconductor dies, then encapsulation and protection are achieved, but halide contaminants diffuse through copper pads to contaminate vias
Solution Approach 1:
The slot filled with insulating material serves as an intermediary layer between the molding compound and the copper pad/via structure. This intermediary barrier allows the molding compound to provide encapsulation protection while preventing the diffusion of halide contaminants to the sensitive electrical interconnects.
Solution Approach 2:
The slot structure converts the potential harm of direct exposure by creating a controlled barrier. The insulating material in the slot, which would otherwise be a defect in the conductive pad, is transformed into a beneficial protective feature that blocks contamination while allowing the molding process to proceed with its protective function.
3Object-affected harmful factors
If a slot filled with insulating material is introduced through the conductive pad, then contamination protection is improved, but device structure complexity increases
Solution Approach 1:
The slot introduces a simple segmentation to the pad structure - a single linear division filled with insulating material. This minimal segmentation approach provides effective contamination protection without creating complex multi-layer or multi-component structures, maintaining fabrication simplicity.
Solution Approach 2:
The insulating material is applied locally only in the slot region where contamination protection is needed, rather than modifying the entire pad structure. This localized approach protects the vias from contamination while maintaining the electrical conductivity of the rest of the copper pad, avoiding unnecessary structural 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 design enhances the reliability of the electrical connection by reducing contamination and corrosion, thereby improving the unbiased highly accelerated stress test (UHAST) performance of the semiconductor structure.
Implementation Method 1
Due to the heat and humidity applied during the molding process, these contaminates may diffuse through the copper pads of the bond pad structures to reach the vias thereunder
Implementation Method 2
The slot may be arranged laterally between the exposed portion of the conductive pad and the plurality of electrical interconnects
Data Source
AI summary
A semiconductor structure may be provided, including a conductive pad, a slot arranged through the conductive pad, a passivation layer arranged over the conductive pad and a plurality of electrical interconnects arranged under the conductive pad. The conductive pad may include an electrically conductive material and the slot may include an electrically insulating material. The passivation layer may include an opening that may expose a portion of the conductive pad and the slot may be arranged laterally between the exposed portion of the conductive pad and the plurality of electrical interconnects.