Semiconductor Storage Contact Pad Structure for Bonding Reliability

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Solution Overview

Problem

Forming a pad on a contact plug connected to a circuit chip via a memory chip is difficult in semiconductor storage devices like NAND flash memory.

Innovation Solution

A semiconductor storage device comprising a first chip with a transistor and a second chip with a memory cell array, where a contact extends between the first and second surfaces, and a first wiring layer is provided above a contact end, connected to a first conductive layer, which is between the contact and the wiring layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a pad is formed directly on a contact plug connected to a circuit chip via a memory chip, then the connection reliability is improved, but the manufacturing difficulty increases significantly

Engineering Contradiction:
Improveconnection reliabilityVSAvoidmanufacturing difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent introduces a conductive layer as an intermediary between the contact plug and the pad. This conductive layer serves as a mediator that facilitates the formation of the pad on the contact plug, reducing the direct manufacturing difficulty while maintaining connection reliability. The conductive layer acts as a buffer and transition structure that simplifies the overall manufacturing process.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent divides the connection structure into multiple segments: the contact plug, the conductive layer, and the pad. By segmenting the direct contact structure into separate functional layers, the manufacturing process becomes more manageable and less difficult, while each segment contributes to the overall connection reliability.

Inventive Principle:
Principle #1Segmentation

2Productivity

If wire bonding is performed directly on the contact plug, then the connection is established, but the contact plug suffers from bonding damage

Engineering Contradiction:
Improveconnection establishmentVSAvoidcontact plug integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The conductive layer serves as a protective intermediary between the wire bonding process and the contact plug. The wire is bonded to the conductive layer rather than directly to the contact plug, which protects the contact plug from bonding damage while still establishing the necessary electrical connection.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The conductive layer is formed beforehand as a protective cushioning layer that absorbs the mechanical stress and damage from the wire bonding process, preventing this damage from reaching the contact plug and compromising its integrity.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Productivity

If the pad formation process is simplified, then the manufacturing efficiency is improved, but the device size may increase

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoiddevice size
Core Design Contradiction:
ProductivityVSVolume of moving object

Solution Approach 1:

The patent merges the conductive layer formation with the existing manufacturing process flow, combining multiple functions into integrated process steps. This merging approach simplifies the overall manufacturing process and improves efficiency without requiring additional space-bonus structures.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The conductive layer is formed in a different dimensional plane or processing layer, allowing the pad formation to occur in an optimized configuration that maintains compact device dimensions while simplifying the manufacturing process through alternative process sequencing.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4676182A1Semiconductor storage device and manufacturing method thereof
Publication Date: 2026.01.07 KIOXIA CORP
  • EP4676182A1 patent drawingFigure 1
  • EP4676182A1 patent drawingFigure 2
  • EP4676182A1 patent drawingFigure 3

AI summary

A semiconductor manufacturing device in which a pad can be easily formed on a contact plug and a manufacturing method thereof are provided. A semiconductor storage device according to the present embodiment includes a first chip including a transistor and a second chip including a memory cell array. The second chip has a first surface bonded to the first chip and a second surface opposite the first surface. A contact extends between the first surface and the second surface and is provided apart from the memory cell array. A first wiring layer is provided above a first end of the contact, which is an end on a second surface side, and is electrically connected to the contact. A first conductive layer is provided between the first end of the contact and the first wiring layer.