TSV Test Structure for Wafer-Stage Abnormal Via Detection

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Solution Overview

Problem

Existing methods are inadequate for detecting the integrity and quality of through-substrate vias (TSVs) on wafers during the wafer stage, making it difficult to identify abnormal TSVs.

Innovation Solution

A TSV test structure is introduced, which includes a substrate with a test region, a first TSV located within the substrate, and a test device positioned on the substrate. The test device and TSV are separated by a distance of less than 10 μm, allowing the stress from the TSV to affect the electrical properties of the test device, thereby enabling detection of abnormal TSVs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If general wafer test method is used, then the testing process is simple, but the integrity and quality of TSV cannot be detected

Engineering Contradiction:

ImproveTSV detection capabilityVSAvoidtest structure complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The substrate is divided into a device region and a test region, with the test region further containing a test device and a TSV. This segmentation allows independent testing of TSV quality without affecting the device region, enabling precise TSV detection while keeping the overall structure manageable.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A test device is introduced as an intermediary element between the TSV and the measurement system. The test device includes a test element that interacts with the TSV through stress coupling, translating TSV integrity information into measurable electrical property changes without requiring direct complex measurement of the TSV itself.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If test device is placed close to TSV, then stress effect on electrical property is enhanced, but manufacturing precision requirement increases

Engineering Contradiction:

Improvestress detection sensitivityVSAvoidpositioning accuracy

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The test device is positioned within a specific distance range (5-15 μm) from the TSV, optimizing the stress coupling effect. This parameter optimization ensures sufficient sensitivity for detecting TSV abnormalities while remaining achievable with standard manufacturing capabilities, balancing detection precision with manufacturing feasibility.

Inventive Principle:

Principle #35Parameter changes

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

The TSV test structure effectively detects abnormal TSVs by measuring changes in the electrical properties of the test device, which are caused by stress from the TSV. This method is compatible with wafer acceptance tests and does not require additional processing steps.

Implementation Method 1

the stress of the TSV will affect the electrical property (e.g., threshold voltage (Vt), on-current (Ion), or capacitance) of the test device

Methodology Applied

Scientific EffectStress:

Data Source

PatentUS12278149B2Through-substrate via test structure

Publication Date: 2025.04.15 POWERCHIP SEMICON MFG CORP

AI summary

A through-substrate via (TSV) test structure including a substrate, a first TSV, and a test device is provided. The substrate includes a test region. The first TSV is located in the substrate of the test region. The test device is located on the substrate of the test region. The test device and the first TSV are separated from each other. The shortest distance between the test device and the first TSV is less than 10 μm.