Stacked-Chip TSV Structure Without Additional Conductive Bumps

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Solution Overview

Problem

Conventional through silicon via (TSV) technology requires additional conductive structures, such as solder balls, to establish electrical connections between chips, complicating the semiconductor structure and manufacturing process.

Innovation Solution

The method involves forming TSVs that penetrate through the second chip and a part of the first chip, with a conductive layer in the TSV, allowing for electrical connection between the metal layers of the two chips without additional conductive structures. This simplifies the semiconductor structure and process steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional conductive structures (such as solder balls) are used to establish electrical connections between chips, then electrical connection reliability is improved, but device complexity and manufacturing process complexity increase

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the TSV structure with the inter-chip connection function by extending the TSV through the bonding interface. The conductive layer within the TSV continuously connects metal layers across both chips, eliminating the need for separate solder balls or conductive bumps. This integration of connection pathways into the TSV structure itself reduces device complexity while maintaining electrical connection reliability.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If additional conductive structures (such as solder balls) are used to establish electrical connections between chips, then electrical connection reliability is improved, but manufacturing process complexity increases

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The manufacturing process merges TSV formation with inter-chip connection creation. The same etching, insulating layer deposition, and conductive layer formation steps that create TSVs also establish the continuous conductive pathways through the bonding interface. This eliminates separate manufacturing steps for adding solder balls or conductive bumps, thereby simplifying the overall manufacturing process while ensuring reliable electrical connections.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent performs preliminary action by forming the conductive layer in the TSV before the bonding process. The TSV is prepared with the conductive layer in advance, so that when chips are bonded together, the conductive pathways are already established and ready to connect metal layers across the interface. This preliminary preparation eliminates the need for post-bonding steps to add conductive structures.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If TSV penetrates through both chips to enable direct electrical connection, then device complexity is reduced, but manufacturing precision requirements increase

Engineering Contradiction:
Improvestructure complexityVSAvoidTSV alignment precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent applies the nesting principle by placing the TSV structure within the bonding interface region. The TSV extends through the bonding layer and aligns with metal layers in both chips, creating a nested configuration where the conductive pathway is embedded within the bonded structure. This nesting approach allows the TSV to serve dual purposes (internal connection and inter-chip connection) while managing alignment requirements through the bonding process.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP4207262B1Semiconductor structure and preparation method therefor
Publication Date: 2025.04.23 CHANGXIN MEMORY TECH INC
  • EP4207262B1 patent drawingFigure 1
  • EP4207262B1 patent drawingFigure 2
  • EP4207262B1 patent drawingFigure 3~4

AI summary

The present application provides a semiconductor structure and a manufacturing method thereof. The manufacturing method includes: providing a stacked structure, the stacked structure includes a first chip and a second chip; forming a through silicon via (TSV) in the stacked structure, the TSV includes a first part and a second part communicating with the first part, a sidewall of the first part is a vertical sidewall, and a sidewall of the second part is an inclined sidewall; forming an insulating layer on the sidewall of the first part; and forming a conductive layer in the TSV. By forming the TSV penetrating through the second chip and a part of the first chip, and forming the conductive layer in the TSV, the semiconductor structure and the manufacturing method thereof in the present application can implement electrical connection between the metal layers in the first chip and the second chip without an additional conductive structure, and thus the semiconductor structure and the process steps can be simplified. With the inclined sidewall of the second part, the present application only forms the insulating layer on the sidewall of the first part to simplify the process steps and reduce the cost.