TSV Barrier Layer Stack for Copper Drift Isolation
Find Innovative SolutionsGenerate Solutions
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 the formation of 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 and improve electrical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copper is filled in TSV vias and barriers are formed, then electrical conductivity is improved, but copper drift causes current leakage and reliability degradation
Solution Approach 1:
A nitrogen-containing dielectric layer is introduced as an intermediary barrier between the copper fill and the TSV liner oxide. This intermediate layer prevents direct interaction between copper atoms and the oxide surface, thereby stopping copper drift and re-sputtering while maintaining electrical conductivity through the via structure.
Solution Approach 2:
The nitrogen-containing dielectric layer is formed beforehand to prevent copper drift before it can occur. By pre-establishing this protective barrier, the harmful re-sputtering of copper onto the TSV liner oxide is prevented from happening in the first place, rather than attempting to remove or correct the problem after copper drift occurs.
2Ease of manufacture
If re-sputtered copper is not protected, then manufacturing process is simplified, but TSV liner breakdown voltage degrades due to metal contamination
Solution Approach 1:
The nitrogen-containing dielectric layer serves as a protective intermediary that maintains TSV liner breakdown voltage by preventing metal contamination. This intermediate layer is integrated into the existing manufacturing flow, providing the necessary protection without requiring complex additional process steps.
3Reliability
If barrier layers are added to prevent copper drift, then reliability is improved, but device complexity increases
Solution Approach 1:
The nitrogen-containing dielectric layer is applied locally only in the critical regions where copper drift prevention is needed, such as at the TSV via interfaces and around the copper fill. This localized approach provides necessary protection while minimizing the overall structural complexity and avoiding unnecessary material additions throughout the entire device.
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 method reduces the probability of leakage and enhances the electrical performance of semiconductor devices by isolating re-sputtered metals from dielectric layers through the use of barrier layers.
Implementation Method 1
removing oxides formed from the exposed first metal and the exposed second metal and forming a re-sputtered first metal and a re-sputtered second metal 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.