TSV Barrier Layer Stack to Prevent Copper Drift Leakage
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Solution Overview
Problem
Copper drift in semiconductor devices leads to current leakage and reliability issues due to re-sputtering onto TSV liner oxide, causing resistance variations and degradation of breakdown voltage.
Innovation Solution
A method involving forming a third and fourth barrier layer to separate re-sputtered metals from dielectric layers, using blanket deposition and in-situ argon plasma sputter cleaning to reduce metal contamination, followed by filling with a conductive material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copper is filled in TSV vias to improve electrical conductivity, then electrical performance is improved, but copper drift and re-sputtering cause current leakage and reliability degradation
Solution Approach 1:
A nitrogen-containing barrier layer is introduced as an intermediary between the copper fill and the dielectric layer. This barrier layer prevents copper atoms from migrating and re-sputtering onto the dielectric during subsequent processing, thereby eliminating the harmful copper drift effect while maintaining electrical conductivity
Solution Approach 2:
The barrier layer is formed by changing the chemical composition parameters of the interface between copper and dielectric. By introducing a nitrogen-containing material with different chemical properties, the interface characteristics are modified to prevent copper migration and improve reliability
2Reliability
If multiple barrier layers are formed to prevent copper drift, then reliability is improved, but manufacturing complexity increases
Solution Approach 1:
The barrier layer formation process is merged with existing manufacturing steps. The nitrogen-containing barrier layer is deposited using the same PVD equipment and process conditions as the existing TSV liner and barrier layers, combining multiple functions into a single integrated process step that reduces overall manufacturing complexity
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
Reduces the probability of leakage and improves electrical performance by isolating re-sputtered metals from dielectric layers, enhancing semiconductor device reliability.
Implementation Method 1
removing oxides formed from the exposed first metal and the exposed second metal is performed by an in-situ argon plasma sputter cleaning process
Implementation Method 2
forming the third dielectric layer on the substrate and the bottom and the inner sidewalls of the first via and the second via is performed by a blanket deposition process
Data Source
AI summary
The present disclosure provides a method of manufacturing a semiconductor device. The method includes: forming a first via and a second via on a semiconductor structure, wherein the semiconductor structure includes a first dielectric layer, a first barrier layer, a first metal, a second barrier layer, a second dielectric layer, a substrate, and a second metal; forming a third dielectric layer on the substrate and a bottom and the inner sidewalls of the first via and the second via; punching through the third dielectric layer on the bottom of the first via and the second via; forming a third barrier layer on the substrate and in the first via and the second via; removing oxides formed from the first metal and the second metal; forming a fourth barrier layer; and forming a conductive material in the first via and the second via.