Through-Silicon Via Stress Relaxation via Insulating Film Gap
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Solution Overview
Problem
Conventional methods for relaxing stress in semiconductor substrates induced by through-silicon vias require additional processes and materials, complicating the manufacturing process and limiting performance.
Innovation Solution
A semiconductor device with a through-silicon via and an insulating film gap between the substrate and the via, where the gap is formed by removing the upper part of the insulating film to equalize distance and depth, and a second interlayer insulating film is embedded in part of the gap, using a silicon nitride film to reduce stress on the transistor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional stress relaxation methods (adding metal layers or relaxation layers) are used, then stress on the semiconductor substrate is reduced, but the manufacturing process becomes more complex and material selection is limited
Solution Approach 1:
The patent extracts the stress-inducing element (metal in through-silicon via) from direct contact with the semiconductor substrate by creating a gap between them. This is achieved by removing the insulating film in the region close to the substrate surface, allowing the metal to be separated from the substrate while maintaining electrical connectivity through the via, thereby reducing stress without adding complex layers
Solution Approach 2:
The patent introduces an intermediary structure (the gap formed by removing insulating film) between the metal in the through-silicon via and the semiconductor substrate. This intermediary gap acts as a stress isolation zone that prevents direct stress transmission from the metal to the substrate, achieving stress relaxation without requiring additional functional layers
2Reliability
If thick copper is used in through-silicon via, then electrical conductivity is improved, but thermal expansion stress on the semiconductor substrate increases
Solution Approach 1:
The patent extracts the source of thermal expansion stress by creating a gap that separates the thick copper from the semiconductor substrate. This allows the use of thick copper for electrical conductivity while preventing the thermal expansion stress from being transmitted to the substrate, as the gap acts as a stress isolation zone
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 configuration effectively relaxes stress on the semiconductor substrate, preventing property fluctuations in transistors near the through-silicon via, enhancing the reliability and performance of the semiconductor device.
Implementation Method 1
This configuration effectively relaxes stress on the semiconductor substrate, preventing property fluctuations in transistors near the through-silicon via
Implementation Method 2
stress is generated on semiconductor substrate 11 due to a difference in a thermal expansion coefficient between copper and silicon forming semiconductor substrate 11
Data Source
AI summary
The present invention aims to relax stress induced by through-silicon via formed on semiconductor substrate in order to prevent property fluctuation of a transistor. A semiconductor device includes a semiconductor substrate, a through-silicon via formed in semiconductor substrate, an insulating film formed between the semiconductor substrate and the through-silicon via, and a transistor formed on the semiconductor substrate so as to be apart from the through-silicon via with a predetermined distance. The insulating film does not exist on a region close to a surface of the semiconductor substrate between the semiconductor substrate and the through-silicon via. A gap is formed to be surrounded by the semiconductor substrate, the through silicon via, and the insulating film under the region close to the surface of the semiconductor substrate.