Wire-Protrusion Bond Structure Without CMP Flattening

Solution Overview

Problem

Current hybrid bonding techniques for semiconductor wafers and devices result in uneven bonding surfaces due to chemical mechanical polishing (CMP) processes, leading to decreased bonding strength and reliability.

Innovation Solution

A bond structure comprising a seed layer and a conductive structure with a via portion and a plurality of wires protruding from the via portion, where the seed layer is on the lateral surface of the via portion and has a different material composition than the wires, eliminating the need for CMP processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If chemical mechanical polishing (CMP) processes are performed on semiconductor wafers before bonding, then the bonding surfaces can be flattened, but the bonding surfaces become uneven due to process limitations, resulting in decreased bonding strength and reliability

Engineering Contradiction:

Improvebonding surface flatnessVSAvoidbonding strength

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies preliminary action by forming protrusions on the bonding surfaces before the bonding process. These protrusions are pre-formed through a controlled process that creates intentional surface features, which then engage with complementary features on the opposing wafer during bonding. This pre-prepared surface structure ensures reliable mechanical interlocking and electrical connection, eliminating the need for CMP while maintaining or improving bonding strength and reliability.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If chemical mechanical polishing (CMP) processes are performed on semiconductor wafers, then surface flatness can be improved, but the manufacturing process complexity and cost increase

Engineering Contradiction:

Improvebonding surface flatnessVSAvoidmanufacturing process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies the extraction principle by removing the CMP process from the manufacturing sequence entirely. Instead of using CMP to achieve surface flatness, the invention extracts the surface preparation function and replaces it with a protrusion formation process that is integrated into the existing fabrication steps. This eliminates the need for separate CMP equipment and process control, thereby reducing manufacturing process complexity and cost while still achieving the desired surface characteristics for reliable bonding.

Inventive Principle:

Principle #2Taking out (Extraction)

3Manufacturing precision

If chemical mechanical polishing (CMP) processes are performed on semiconductor wafers, then surface flatness can be improved, but the bonding strength decreases due to surface unevenness

Engineering Contradiction:

Improvebonding surface flatnessVSAvoidbonding strength

Core Design Contradiction:

Manufacturing precisionVSStrength

Solution Approach 1:

The patent applies preliminary action by forming protrusions on the bonding surfaces before the bonding process. These protrusions are pre-formed through a controlled process that creates intentional surface features, which then engage with complementary features on the opposing wafer during bonding. This pre-prepared surface structure ensures reliable mechanical interlocking and electrical connection, eliminating the need for CMP while maintaining or improving bonding strength and reliability.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20250038106A1Bond structure

Publication Date: 2025.01.30 ADVANCED SEMICON ENG INC

AI summary

A bond structure is provided. The bond structure includes a seed layer and a conductive structure. The conductive structure includes a via portion over the seed layer and a plurality of wires protruding from the via portion.