Through Electrode Capping with Self-Aligned Protection Layers
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Solution Overview
Problem
Existing semiconductor devices with through electrodes face electrical defectiveness due to diffusion of metallic constituents, which affects their electrical characteristics and reliability.
Innovation Solution
A semiconductor device structure where the top portion of the through electrode is capped with a self-aligned protection layer, comprising a conductive material like copper and silicon, and an optional second layer with nitrogen, to prevent diffusion and enhance electrical connectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If through electrodes are used to electrically connect semiconductor devices, then electrical connectivity and three-dimensional mounting are improved, but metallic constituents diffuse away from the through electrode causing electrical defectiveness
Solution Approach 1:
A protection layer comprising copper and silicon is formed as an intermediary between the through electrode and the surrounding environment. This protection layer acts as a barrier that prevents metallic constituents from diffusing away while maintaining electrical connectivity. The protection layer is formed by providing a copper layer and then reacting it with a reaction gas containing silicon to form a copper-silicon compound layer.
Solution Approach 2:
The protection layer is formed as a composite material combining copper and silicon in a copper-silicon compound structure. This composite material provides both protective function (preventing diffusion) and maintains electrical properties. The composite structure of copper and silicon compounds offers superior performance compared to single-material barriers.
2Reliability
If conventional protection methods are used, then some diffusion prevention is achieved, but additional alignment steps and complexity are required
Solution Approach 1:
The protection layer formation process is self-aligning to the through electrode structure. The copper layer is formed to fill or cover the through electrode, and subsequent silicon reaction automatically creates the protection layer precisely where needed on the through electrode surface. This self-service mechanism eliminates the need for separate alignment steps and complex positioning procedures.
Solution Approach 2:
The copper layer is formed in advance on or around the through electrode before the silicon reaction occurs. This preliminary action ensures that when the reaction gas is introduced, the silicon reacts specifically with the copper layer to form the protection layer in the correct position, preventing diffusion before it can occur during subsequent processing steps.
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 self-aligned protection layers effectively prevent the diffusion of metallic constituents, reducing electrical defects and improving the electrical characteristics and reliability of the semiconductor devices.
Implementation Method 1
The top end of the through electrode may be capped with a first protection layer capable of preventing a constituent of the through electrode from being diffused away from the through electrode
Implementation Method 2
The first protection layer may include a combination of copper and silicon
Data Source
AI summary
Semiconductor devices having through electrodes capped with self-aligned protection layers. The semiconductor device comprises a semiconductor substrate including an integrated circuit formed therein, an interlayer dielectric layer on the semiconductor substrate to cover the integrated circuit, an intermetal dielectric layer having at least one metal line that is provided on the interlayer dielectric layer and is electrically connected to integrated circuit, and a through electrode that vertically penetrates the interlayer dielectric layer and the semiconductor substrate. The through electrode includes a top portion that is capped with a first protection layer capable of preventing a constituent of the through electrode from being diffused away from the through electrode.