Through Silicon Via Insulation Structure for Semiconductor Reliability
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Solution Overview
Problem
Conventional semiconductor devices with through silicon vias (TSV) face reliability issues due to insulation film deterioration, leading to reduced performance and reliability.
Innovation Solution
A method and semiconductor device design that includes forming a through hole in a semiconductor substrate, extending an insulation film from the bottom of the hole to the surface, coating an organic member on the insulation film, removing air bubbles, and forming an opening to create a through electrode with a thicker conductive layer on the surface than within the hole, enhancing insulation and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an insulation film is disposed in the through hole formed in the silicon substrate, then the electrical insulation is provided, but the reliability is lowered when the insulation film deteriorates
Solution Approach 1:
The patent uses a composite insulation structure consisting of an inorganic insulation film (such as silicon oxide or silicon nitride) combined with an organic insulation film (such as benzocyclobutene or polyimide). This composite structure leverages the advantages of both materials: the inorganic film provides excellent electrical insulation and thermal stability, while the organic film offers flexibility and stress relief, together preventing deterioration and enhancing long-term reliability.
Solution Approach 2:
The patent applies a stress relief layer or buffer layer between the insulation film and the through-hole walls to preemptively compensate for thermal expansion mismatches and mechanical stresses. This beforehand cushioning prevents crack formation and film deterioration before they occur, maintaining insulation integrity over the device lifetime.
2Reliability
If the conductive layer thickness is increased on the surface, then the electrical connectivity is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent implements a through-electrode structure where the conductive layer thickness is locally optimized: thicker at the surface for excellent electrical connectivity and signal integrity, and tapered or thinner deeper in the hole to reduce manufacturing difficulty and material usage. This local quality variation achieves high reliability without proportionally increasing overall manufacturing complexity.
Solution Approach 2:
The patent employs preliminary plating or seed layer formation before the main conductive layer deposition. This preliminary action creates a foundation that facilitates subsequent thick conductive layer formation on the surface while maintaining process control, reducing the overall manufacturing complexity despite the increased thickness requirement.
Data Source
AI summary
A semiconductor device includes a semiconductor substrate having a first main surface and a second main surface opposite to the first main surface; a first conductive layer disposed on the second main surface; a second conductive layer passing through the semiconductor substrate from the first main surface to the second main surface so that the second conductive layer is connected to the first conductive layer; an organic insulation film disposed to contact with the first conductive layer; and a first insulation layer disposed to contact with the organic insulation film. The second conductive layer has a first portion passing through the semiconductor substrate so that the first portion contacts with the semiconductor substrate through the organic insulation film and the first insulation layer.