Backside Bonding Structure for TSV Protection

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Solution Overview

Problem

Existing semiconductor devices with through-silicon via (TSV) structures face challenges in protecting the backside end of TSVs from damage during subsequent processes like etching, grinding, or polishing, which can lead to adhesion degradation and affect yield, performance, and life cycle.

Innovation Solution

The semiconductor devices incorporate a backside bonding structure with a T-shaped longitudinal cross-section, featuring a backside bonding via plug portion and interconnection portion, where the backside bonding barrier layer is in direct contact with the TSV barrier layer, and the TSV structure has a recessed backside end to prevent exposure and damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the backside end of the TSV structure is exposed for subsequent processes like etching, grinding, or polishing, then manufacturing flexibility is improved, but the TSV structure becomes vulnerable to physical and chemical attacks leading to adhesion degradation

Engineering Contradiction:

Improvemanufacturing flexibilityVSAvoidadhesion strength

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies preliminary action by forming a protective layer over the backside end of the TSV structure before subsequent manufacturing processes. This protective layer is prepared in advance to prevent physical and chemical attacks during etching, grinding, or polishing operations, thereby maintaining adhesion strength while enabling manufacturing flexibility.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses an intermediary protective layer as a mediator between the TSV structure and the harsh chemical/physical environment of subsequent processes. This intermediary layer shields the TSV backside end from direct exposure to etchants and mechanical stress, preventing adhesion degradation while allowing the manufacturing processes to proceed.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the TSV structure is fully protected from subsequent processes, then adhesion and reliability are maintained, but access to the TSV backside end for bonding connections is restricted

Engineering Contradiction:

Improveadhesion strengthVSAvoidaccessibility for bonding

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent applies local quality by providing differentiated protection: the protective layer covers the TSV backside end to maintain adhesion, while specific localized areas are left accessible or selectively opened to allow bonding connections. This enables simultaneous achievement of reliability through protection and ease of operation through localized access points.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent segments the protective coverage by dividing the TSV backside end into protected regions and accessible regions. The protective layer is applied selectively to certain areas while leaving other areas exposed or providing controlled access, thereby balancing adhesion maintenance with bonding accessibility.

Inventive Principle:

Principle #1Segmentation

3Manufacturing precision

If the TSV structure is exposed to etching, grinding, or polishing processes, then substrate thinning and planarization are achieved, but the backside end of the TSV structure suffers damage and adhesion degradation

Engineering Contradiction:

Improvesubstrate planarizationVSAvoidphysical and chemical attacks

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies beforehand cushioning by providing a protective layer over the TSV backside end before the substrate undergoes etching, grinding, or polishing processes. This protective layer acts as a cushion that absorbs or resists the physical and chemical attacks during these processes, preventing damage to the TSV structure while allowing substrate planarization to proceed.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent converts the potentially harmful effects of etching, grinding, and polishing into beneficial outcomes by using the protective layer to enable these processes to proceed. The harmful physical and chemical attacks are redirected or neutralized by the protective layer, allowing substrate thinning and planarization to be achieved without damaging the TSV backside end.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS9147640B2Semiconductor devices having back side bonding structures

Publication Date: 2015.09.29 SAMSUNG ELECTRONICS CO LTD

AI summary

Semiconductor devices are provided including an internal circuit on a front side of a substrate, the substrate defining a through-silicon via (TSV) structure extending vertically therein; a back side insulating layer on a back side of the substrate; and a back side bonding structure on the back side insulating layer. The TSV structure includes a front side end on a front side of the substrate and contacts the internal circuit and a back side end extending toward a back side of the substrate. The back side bonding structure includes a back side bonding interconnection portion on the back side insulating layer defining a back side bonding via hole therein and a back side bonding via plug portion in the contact plug hole in the back side insulating layer connected to a back side end of the TSV structure.