Low-Capacitance Through-Substrate Via Structure for Stable Signal Speed

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Solution Overview

Problem

Semiconductor devices with through substrate conductive paths face reliability issues due to parasitic capacitances that affect performance and increase power consumption, and these capacitances may degrade over time.

Innovation Solution

The introduction of additional capacitors in series with the TSV capacitance, coupled to a reference voltage, to maintain the composite capacitance below target levels by isolating individual capacitances, thereby reducing parasitic effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If through substrate conductive paths are formed, then connectivity between substrate layers is improved, but parasitic capacitance increases causing performance degradation

Engineering Contradiction:
ImproveconnectivityVSAvoidparasitic capacitance
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The conductive path is segmented into multiple sections by inserting dielectric material in alternating pattern with conductive material along the via structure. This segmentation divides the continuous conductive path into discrete segments separated by low-k dielectric layers, reducing the overall parasitic capacitance while maintaining electrical connectivity between layers.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If conventional TSV structure is used, then manufacturing simplicity is maintained, but capacitance increases reducing operating speed

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidoperating speed
Core Design Contradiction:
Ease of manufactureVSSpeed

Solution Approach 1:

The alternating conductive and dielectric layers are formed preliminarily during the TSV fabrication process before final via completion. By pre-forming the low-k dielectric layers between conductive segments during the manufacturing process, the structure is prepared in advance to minimize capacitance effects, enabling faster signal propagation without complicating the overall manufacturing flow.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3427294B1Low capacitance through substrate via structure and method of fabrication
Publication Date: 2025.12.03 MICRON TECHNOLOGY INC
  • EP3427294B1 patent drawingFigure 1A~1C
  • EP3427294B1 patent drawingFigure 2A~2C
  • EP3427294B1 patent drawingFigure 3A~3E

AI summary

Apparatuses and methods are disclosed herein for the formation of low capacitance through substrate via structures. An example apparatus includes an opening formed in a substrate, wherein the opening has at least one sidewall, a first dielectric at least formed on the sidewall of the opening, a first conductor at least formed on the first dielectric, a second dielectric at least formed on the first conductor, and a second conductor at least formed on a sidewall of the second dielectric.