Asymmetric Through Semiconductor Via Filling Method

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Solution Overview

Problem

Conventional through semiconductor via technology faces challenges in filling conductive material into through holes due to contamination and defects, especially when the opening on the opposite side of the substrate is smaller, leading to uneven and insufficient filling, which affects the conductive properties and reliability of the connections.

Innovation Solution

The method involves forming a through hole with a larger opening on the opposite side of the substrate by etching and filling it with a filling material, which is then removed to allow easy filling with a conductive material, ensuring better filling and reducing defects such as voids, thereby improving the conductive properties and reliability of the connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the through hole is filled with conductive material from the side where the opening is smaller, then the functional device can be formed first, but the conductive material cannot be filled evenly and sufficiently, leading to defects

Engineering Contradiction:

Improveconductive material filling qualityVSAvoiddifficulty of filling conductive material

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The through hole is designed with an asymmetric cross-sectional shape where the opening area at the second surface (opposite to the functional device side) is larger than the opening area at the first surface. This asymmetric geometry allows conductive material to be filled easily from the larger opening while maintaining proper alignment with the functional device, resolving the contradiction between filling quality and manufacturing ease

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

Instead of filling the through hole from the conventional side (where the opening is smaller and aligned with the functional device), the invention inverts the filling approach by filling from the opposite side where a larger opening is created. This inversion enables better filling while still achieving proper conductive material placement

Inventive Principle:

Principle #13The other way round (Inversion)

2Ease of manufacture

If the through hole opening at the opposite side is made larger to facilitate conductive material filling, then filling becomes easier, but the vertical section shape becomes more complex

Engineering Contradiction:

Improveease of filling conductive materialVSAvoidvertical section shape of through hole

Core Design Contradiction:

Ease of manufactureVSShape

Solution Approach 1:

The through hole employs an asymmetric cross-sectional configuration where one opening (at the second surface) is deliberately made larger than the other. This asymmetric design simplifies the filling process from the larger opening while the complex shape is confined to the internal structure, resolving the trade-off between manufacturing ease and geometric complexity

Inventive Principle:

Principle #4Asymmetry

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach allows for easier and more reliable filling of conductive material into the through holes, reducing defects and enhancing the electro-migration and stress migration performance of the connections by utilizing a larger opening for filling, resulting in improved conductive properties.

Implementation Method 1

etching a portion of the substrate from the first surface of the substrate to form a first portion of an opening

Methodology Applied

Scientific EffectEtching:

Data Source

PatentUS8476163B2Semiconductor device and manufacturing method therefor

Publication Date: 2013.07.02 SEMICON MFG INT (SHANGHAI) CORP

AI summary

A method for manufacturing a semiconductor device includes providing a substrate having a first surface and a second surface, the second surface is on the opposite side of the substrate facing away from the first surface. The method further includes forming a first portion of an opening by etching a portion of the substrate from the first surface, forming a buffer layer on an inner surface of the first portion, etching a bottom of the buffer layer to expose an area of the underlying substrate, and etching the exposed area of the substrate to form a second portion of the opening. The method also includes performing an isotropic etching on the second portion of the opening to obtain a flask-shaped opening and filling the opening with a filling material. The method also includes partially removing a portion of the second surface and the filling material from the second portion of the opening.